JPH03225263A - Inspecting device - Google Patents

Abstract

PURPOSE:To inspect the existence of a flaw on a work by rotating the work up to 180 deg. in each fixed angle, calculating the ratio of a bright part to a dark part and comparing the calculated rate with an optional threshold value by a binarizing means for binarizing a video signal. CONSTITUTION:The work 1 held and positioned by a holding means 2 is irradiated with light projected from an illumination 5 from its approximate front, the reflected light is detected by the approximate front of a camera 4 and the detected light is transmitted to an amplifier 6. A video signal from the amplifier 6 is binarized to a fixed level by a comparator 7, bright part and dark part signals are divided and applied to a gate circuit 8, a clock pulse is gated at the levels of respective parts of the work 1, the gated values are counted by counters 9, 10, the ratio of the areas of the bright and dark parts is calculated by a computing element 11 and stored in a memory 12. After completing the operation, a control circuit 13 drives a pulse motor driver 14 to rotate the work 1 by a fixed angle through a pulse motor 3 and repeats the similar operation for finding out the ratio of areas of the bright and dark parts. The similar operation is repeated by rotating the work 1 up to 180 deg. to inspect the existence of a flaw on the work 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to the prevention of defects (1) in the contents of resin molded products, especially stretch molded products.
! This relates to a device for inspecting a cross section of a material.

[Prior Art] Conventional inspections for defects (roughness) in resin molded products include visual inspection and image processing technology.

[Problems to be Solved by the Invention] The former visual inspection of the above-mentioned conventional inspection was inaccurate because quantitative judgment could not be made. Furthermore, in the latter case, what is discriminated by binarization is the appearance of the cross section, which may change due to, for example, cutting scratches, and methods that perform data processing by multi-value conversion are expensive.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned conventional problems, and includes means for holding and rotating a workpiece, means for imaging a cross section of the held workpiece from a vertical plane, illumination means for irradiating a light source from a substantially vertical surface of the held work; means for binarizing the video signal from the imaging means; means for counting each binarized value; The present invention proposes an inspection device having means for comparing values.

[Operation] The inspection device of the present invention rotates the workpiece to be inspected while holding it, compares each sampled binary value, and finds the value with the maximum (minimum) ratio, thereby inspecting the workpiece. It detects defects.

[Example code] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram of the entire inspection apparatus of the present invention, FIG. 2 is a schematic diagram of the present invention, and FIG. 3 is a diagram showing each pattern.

Reference numeral 1 denotes a workpiece to be inspected, which is held by holding means 2 such as a collet chuck or an arm. Further, the other end of the holding means 2 is connected to a pulse motor 3 as a driving means. Here, the cross-sectional surface 1a of the work 1
A camera 4 as an image sensor is mounted so as to be substantially perpendicular to the
and lighting 5 are arranged.

Light from the surface 1a of the workpiece 1 irradiated with light by the light source 5 is imaged by the camera 4, and an amplifier 6, a comparator 7 that discriminates the signal from the amplifier 6 at a certain level, and a comparator 7 that discriminates the signal from the amplifier 6 according to the discrimination signal of the comparator 7. A gate circuit 8 is arranged to allow the clock to pass through. Counters 9 and 10 that count the clock from the gate circuit 8; counters 9 and 1;
an arithmetic unit 11 that calculates the ratio of each count value of 0; a memory 12 that stores the results of this arithmetic unit 11;
2 to the pulse motor driver 14 via the control circuit 13
is connected.

In Figure 3, A is an image of the workpiece without grains, B is the shape of the workpiece with grains at the same angle, C is an image of the workpiece when A is rotated by a certain angle, and D is an image of the workpiece when B is rotated by a certain angle. This is a video of the work in case.

Next, to explain the operation, the work 1 (resin molded product) held and positioned by the holding means 2 is irradiated with the light of the illumination 5 from approximately the front, and the reflected light is received by the camera 4 approximately from the front, and the reflected light is received by the amplifier 6. Send to.

The cross section of the workpiece 1 is usually not smooth, but has fine grooves carved in it depending on the direction of the cutter, and the image shows the situation shown in FIG. 3 depending on the presence or absence of defects. The video signal from the amplifier 6 is binarized at a constant level by a comparator 7, separated into bright areas and dark areas, and applied to a gate circuit 8. A gate circuit 8 gates a clock pulse at the level of each part of the workpiece 1, and counters 9 and 10 count the values to calculate the areas of bright and dark parts. Arithmetic circuit 11
calculates the ratio of the areas of the bright and dark areas and stores the result in the memory 12. After the calculation is completed, the control circuit 13 immediately operates the pulse motor driver 14 to rotate the workpiece 1 at a constant angle via the pulse motor 3. Work 1
After rotating the image by a certain angle, the areas of the bright and dark areas and their ratio are determined in the same way as described above. Due to cutting scratches on the cross-sectional surface of the workpiece 1, the state of the image changes depending on the rotation angle of the workpiece 1, and an angle at which substantially total reflection occurs occurs from an optical axis angle within 180 degrees. At this time, when there is a defect (stickiness) in the workpiece 1, the image can be captured as a dark part without being reflected in this part. (See FIGS. 3C and 3D) That is, at this time, the ratio of dark to bright areas approaches zero when there are no defects, and on the other hand, when there are defects, it reaches a value above a certain level.

[Effects of the Invention] Since the present invention is constructed as described above, two relatively simple steps can be taken.
Since a value conversion method is adopted, the workpiece can be digitized at a constant angle of 18
The presence or absence of scratches on the workpiece can be detected by rotating the workpiece to 0 degrees, calculating the ratio of the bright part to the dark part, and comparing the ratio with an arbitrary threshold value.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall block diagram, FIG. 2 is a schematic diagram, and FIG. 3 is a pattern diagram. 1...Workpiece, 2...Holding means, 4.
...Camera, 5...Lighting, 7...
·comparator

Claims (1)

[Claims] means for holding and rotating a workpiece; means for imaging a cross section of the held workpiece from a vertical plane; illumination means for irradiating a light source from a substantially vertical plane of the held workpiece; and a video signal from the imaging means. 1. An inspection device comprising means for binarizing a value, means for counting each binarized value, and means for comparing the counted values.