JPH0221252A - Detection of shape of surface for planar product - Google Patents

Abstract

PURPOSE:To automate an inspection process by a method wherein a dew is formed on either one side of a transparent body or the surface of a body to be inspected or both thereof and the transparent body is brought into contact with the surface of the body to be inspected to detect light reflection from drops of dew-formed water at a non-contact part. CONSTITUTION:As a conveying belt 3 makes contact with a transparent cylinder 1, the rotation of the transparent cylinder 1 synchronizes the movement of the conveying belt 3. Then, a dew formation mechanism 6 is provided near the side X of the conveying belt on the outer circumference of the transparent cylinder 1 to make a dew formation uniform. At this point, when the resulting tight contact is viewed from the inside of the transparent cylinder 1, a contact image of an object to be inspected as illustrated. When a flaw exists on the surface of the object 8 to be inspected, a flaw part 15 appearing white can be observed containing the vicinity thereof without contact with the outer circumference of the transparent cylinder 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for detecting the surface shape of a plate-shaped product, and more particularly to a method for detecting surface flaws on a rubber product such as a diaphragm.

(Prior Art) Conventionally, surface flaws on rubber products have been detected using the naked eye, but this has been problematic in that it is inefficient and lacks accuracy.

Therefore, attempts were made to detect surface flaws using a camera and an image processing device.

(Problem to be solved by the invention) In the conventional surface flaw detection method using a camera and an image processing device, conditions such as the lighting environment for capturing surface flaws with the camera and the irradiation angle to the inspected material are difficult to detect. The problem was that setting was difficult due to the different types and materials, and the efficiency and accuracy were not that high despite the effort.

(Means for Solving the Problems) The present invention causes dew condensation on one side of a transparent body or the surface of an object to be inspected, or both, but fine dew condensation makes it possible to detect minute surface conditions, that is, resolution improves. When the roughness of the surface of the object to be inspected is large, this condition is also detected, which causes noise. On the other hand, large condensation drops the resolution, resulting in the opposite effect.

Therefore, the surface properties of the object to be inspected and the surface state to be detected fi1
The state of dew condensation is fi-controlled in consideration of (flaws, shape, etc.).

When a transparent object that has formed condensation is brought into contact with an object to be inspected, the non-contact areas due to surface scratches will receive a large amount of reflected light due to the diffuse reflection of the condensed water droplets, while the contact areas are transparent and there is no light coming from the surface of the object to be inspected. However, the amount of light is generally small, which can make surface scratches or surface shapes obvious.

Since the shape of the object to be inspected in the present invention is detected using a transparent object, it is preferable to use a hard transparent object + a soft object to be inspected or a soft transparent object + a hard object to be inspected.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An outline of a detection apparatus according to the method of the present invention will be explained below with reference to the drawings.

a transparent cylinder 1 rotatably provided by a holding roll 2;
A conveyor belt 3 stretched so as to partially contact the outer peripheral surface of the transparent cylinder l to form a contact part A, a wiping part 4, a drying part 5 and Contact area A between the dew condensation mechanism 6 and the transparent cylinder l and the transport heald 3
It is composed of a camera 7 provided inside a transparent cylinder l and an image processing device (not shown).

(Function) Detection of surface flaws on a rubber product (hereinafter referred to as inspected material) by the method of the present invention will be explained.

Since the conveyor belt 3 is in contact with the transparent cylinder 1, the rotation of the transparent cylinder 1 and the movement of the conveyor heald 3 are synchronized. A dew condensation mechanism 6 is provided on the outer periphery of the transparent cylinder l near the entrance side of the conveyor belt to create a --like dew condensation state.

When the conveyor belt 3 is moved and the outer periphery of the transparent cylinder 1 comes into contact with the material to be inspected 8 on the conveyor belt 3, the outer periphery of the transparent cylinder 1 and the material to be inspected 8 come into close contact with each other using water as a medium.

At this time, when this state of close contact is observed from inside the transparent cylinder 1, a close image of the inspected material is obtained as shown in FIG. if,
If there is a flaw on the surface of the material to be inspected 8, including the vicinity thereof, the outer peripheral surface of the transparent cylinder 1 and 1! ! A visible white wound portion 15 that never wears off is visible. Reference numeral 11 indicates the field of view of the camera, and 13 indicates a dew condensation area.

This state is captured by the camera 7, and image processing is performed to take measures such as issuing an alarm.

The outer periphery of the transparent cylinder 1 that is out of contact with the material to be inspected 8 is
A wiping section on the exit side of the transparent cylinder l removes water droplets and dirt from the surface, and a drying section 5 removes moisture from the surface. The transparent cylinder 1 is continuously subjected to dew condensation by the dew condensation mechanism 6, and the cycle of contacting the inspected material 8 is repeated.

Moreover, instead of placing the camera 7 inside the transparent cylinder l, as shown in FIG. 4, by providing a reflecting mirror 9 inside the transparent cylinder l and installing the camera 7 outside, can be made smaller, and the entire device can be made more compact.

Although the present invention has been described above mainly for detecting scratches on rubber products using a transparent cylindrical body, the present invention is not limited to this, and the transparent body may be a flat plate or a polygonal column, and it goes without saying that the scope of the present invention is not limited to this. It's not something to deviate from.

(Effects of the Invention) According to the method of the present invention, surface flaws on rubber products can be revealed with a simple device, and the inspection process can be automated and highly efficient.

[Brief explanation of the drawing]

1 and 2 are schematic explanatory diagrams of the present invention, FIG. 3 is an explanatory diagram of a state in which flaws on a material to be inspected have become apparent, and FIG. 4 is a detailed explanatory diagram of the present invention. 1: Transparent cylinder 2: Holding roll 3: 11 feeding belt 4: Condensation mechanism agent Patent attorney Chano
Tatsuo Ki No. 4J3 (Satoribe No. θ Factory Test

Claims (1)

[Claims] Condensation is caused on one side of the transparent object or the surface of the object to be inspected, or both surfaces of the object to be inspected, the transparent object and the surface of the object to be inspected are brought into contact, and the diffused reflection of the condensed water droplets on the non-contact area is detected to detect the surface to be inspected. A method for detecting the surface shape of a plate-shaped product, characterized by making the shape of the product obvious.