JPH04248449A - Apparatus for inspecting appearance of molded product - Google Patents

Abstract

PURPOSE:To inspect a molded product with high accuracy by uniformly and automatically adjusting the luminous intensity to the molded product. CONSTITUTION:In an apparatus for inspecting the appearance of a molded product 100 having a projector 10 consisting of a plurality of light projection parts 10-1-10-4 and irradiating the molded product 100 with light and a TV camera 20 obtaining the appearance image of the molded product 100 and discriminating the quality of the molded product 100 based on the appearance image, a control part constituted so that a plurality of divided regions are preset to the appearance image to detect the luminous intensities of the respective divided regions and a control signal is generated on the basis of the difference between the detected luminous intensities of the respective divided regions, a first adjusting part adjusting the projection angle alpha of the projector 10 to the molded product 100 based on the control signal and a second adjusting part adjusting the projection quantities of the respective projection parts based on the control signal are mounted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting the appearance of molded articles, and more particularly to an apparatus for inspecting the appearance of molded articles molded by injection molding.

0002

[Prior Art] Molded by injection molding, for example,
The appearance quality of plastic molded products deteriorates when dents, burrs, sink marks, warpage, etc. occur in the molded product due to short shots. When the molded product is an electronic component such as a connector, it is often small and complex in shape.
The dents and burrs caused by short shots are the main deciding factors in determining whether a product is defective. Conventionally, as a device for inspecting the appearance of such molded products, an irradiation unit irradiates light onto the molded product to be inspected from diagonally above, an imaging device acquires an external image of the molded product, and the system uses the image to acquire an external appearance image of the molded product. There is a method to distinguish between good and bad molded products. This type of device uses images, so if the molded product is not uniformly irradiated with light, the accuracy of the inspection results will decrease.

0003

In the above-described apparatus, the irradiation section is composed of a plurality of light projecting sections in order to irradiate the entire surface of the molded product to be inspected with light. When irradiating light from such an irradiation section, there are variations in the illuminance in the vertical direction (depth direction) due to the irradiation of light from diagonally above the molded product, and changes in the amount of light emitted from multiple light emitting sections. This causes variations in illuminance. For this reason, when conventionally inspecting the appearance of a molded product, it is necessary for the operator of the apparatus to manually make the illuminance uniform for the molded product at the time of initial adjustment or periodically. Also, a special sensor for illuminance adjustment,
A controller is required, which increases cost. An object of the present invention is to provide a molded product appearance inspection device that can automatically adjust the illuminance of the molded product before or between inspections. Another object of the present invention is to provide a molded product appearance inspection device that can be used in conjunction with existing sensors and controllers for illuminance adjustment.

0004

[Means for Solving the Problems] According to the present invention, the irradiation unit includes a plurality of light projecting units and irradiates the molded product with light, and the imaging unit obtains an external image of the molded product, In a molded product appearance inspection device that determines the quality of the molded product based on the appearance image, a plurality of divided regions are set in advance in the appearance image, the illuminance of each divided region is detected, and the detected plurality of divided regions are control means for generating a control signal based on the difference in illuminance between the divided regions;
a first adjustment section that adjusts the light projection angle of the irradiation section to the molded product based on the control signal; and a second adjustment section that adjusts the amount of light projected by each of the plurality of light projection sections based on the control signal. An apparatus for inspecting the appearance of a molded product is obtained, which is characterized by having an adjustment section.

[0005]

[Operation] In the present invention, the control means generates a control signal based on the difference in illuminance of each of a plurality of divided regions set in advance in the external image, and the first adjustment section shapes the irradiation part based on the control signal. Adjust the light projection angle to the product, and
Since the adjustment section adjusts the amount of light emitted from each of the plurality of light emitting sections based on the control signal, the illuminance to the molded product can be automatically adjusted.

[0006]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. Referring to FIG. 1, the molded product appearance inspection apparatus according to the present invention includes a projector 10 that serves as an irradiation section, a TV camera 20 that serves as an imaging means, an image processing section 30, and a light projection angle adjustment section that serves as a first adjustment section. section 40, and a laser light source section 50 that functions as a second adjustment section. Floodlight 1
0 consists of four independent light projecting parts 10-1 to 10-4, and each light projecting part is connected to the molded product 10 as shown in FIGS. 3 and 4.
A laser beam is irradiated from diagonally above 0 in a light projection range PA. On the other hand, the TV camera 20 images the molded product 100 with a camera field of view as shown by the two-dot chain line in FIG. Referring again to FIG. 1, the light projection angle adjustment unit 40 includes an adjustment table 4 that supports the light projector 10 and is movable within a range of the light projection angle α.
1, a motor 42 connected to the adjustment table 41 to make its projection angle α variable, and a projection angle control signal C1 which is a first control signal received from a control section 33 (FIG. 2) to be described later. The motor driver 43 drives the motor 42 based on this signal. The laser light source section 50 is a light projector 10
A laser diode head 52 is connected to the laser diode head 52 via an optical fiber 51, and receives a laser light source control signal C2 which is a second control signal from the control section 33 and controls the laser diode head 52 based on this signal. Laser
It consists of a diode driver 53. Referring to FIG. 2, the image processing section 30 includes a molded product image extraction section 31, an inspection section 32, and a control section 33. The control section 33 includes a projection angle control section 331 and a laser light source control section 332.

The operation of the molded product appearance inspection apparatus according to the present invention will be explained below with reference to FIGS. 1 and 2. The device according to this embodiment can be switched between two modes: illuminance adjustment mode and visual inspection mode. First, the illuminance adjustment mode will be described below. The TV camera 20 captures images by continuously scanning the molded product 100 in the vertical direction as shown by the scanning line XX in FIG. At this time, the TV camera 20 outputs an image signal as shown in FIG. 5 for one scanning line. The molded product image extracting unit 31 receives the image signal from the TV camera 20, and selects one of the image signals having an illuminance equal to or higher than the threshold value BL as the molded product 100.
extracted as an image signal. In this device, molded products 100
The image signals are subject to illumination adjustment and visual inspection. In the present invention, divided regions as shown in FIG. 6 are set for the extracted image signal of the molded product 100, and the projection angle control section 331 and the laser light source control section 332 detect the illuminance of each divided region. and compare illuminance for specific areas.
Based on the comparison results, the projection angle adjustment section 40 and the laser light source section 50 are controlled respectively. This will be explained in detail below. The projection angle control unit 331 calculates the illuminance difference Elt between 1a to 4a and 1b to 4b, which are divided in the vertical direction (or depth direction) among the divided regions in FIG. Here, the average value of illuminance in each area is Lna, L
If nb (n=1 to 4), the illuminance difference Elt is expressed by Equation 1.

[0008]

[Math 1]

However, in this embodiment, N=4. Subsequently, the projection angle control section 331 outputs the projection angle control signal C1 based on the obtained illuminance difference Elt. The controlled amount Lt is calculated by the following equation, if the controlled amount one time before is Lt-1.
Indicated by

0010

[Math 2]

[0011] However, α is a proportionality constant. On the other hand, the laser light source control unit 332 controls four regions divided in the horizontal direction among the divided regions in FIG.
, 3a and 3b, and 4a and 4b, the illuminance difference Ebnt with the preset illuminance L* is calculated. This illuminance difference Ebnt is expressed by Equation 3.

0012

[Math 3]

[0013] However, n=1 to 4. Subsequently, the laser light source control unit 332 outputs the laser light source control signal C2 based on the calculated illuminance difference Ebnt. The control amount Bnt is calculated as follows, assuming that the control amount one time before is Bnt-1.
It is shown by the number 4.

[0014]

[Math 4]

[0015] However, β is a proportionality constant. The light projection angle adjustment section 40 that receives the light projection angle control signal C1 from the light projection angle control section 331 adjusts the light projection angle α by the control amount Lt. On the other hand, the laser light source section 50 receives the laser light source control signal C2 from the laser light source control section 332, and controls each of the divided regions 1a and 1.
b, 2a and 2b, 3a and 3b, and 4a and 4b, each illuminance is adjusted by the control amount Bnt. Automatic adjustment of illuminance is completed in the above manner. Such automatic adjustment can be performed about once a day, in a matter of seconds between tests. Next, in the visual inspection mode, the inspection unit 32 performs a visual inspection of the molded product 100 based on the image signal of the molded product, but its operation is not particularly different from known ones, so it will not be described in detail. In any case, the image processing section 30 is realized by a microcomputer or the like under program control. Note that the laser light source section 50 may be configured with a light source whose illuminance can be adjusted, such as a halogen lamp, and the number of light projecting sections is not limited to four.

[0016]

According to the present invention, it is possible to uniformly and automatically adjust the illuminance to the molded product based on the external appearance image of the molded product, so that highly accurate appearance inspection of the molded product can be performed. Further, according to the present invention, the sensor and controller for illuminance adjustment can be used in combination with existing ones, so that an inexpensive appearance inspection device for molded products can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a molded product appearance inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed block diagram of the image processing section 30 in FIG. 1.

FIG. 3 is a diagram for explaining the operation of the device shown in FIG. 1.

FIG. 4 is a diagram for explaining the operation of the device shown in FIG. 1.

5 is a diagram showing an image signal of the TV camera 20 in FIG. 1. FIG.

FIG. 6 is a diagram showing divided regions of an external appearance image.

[Explanation of symbols]

10 Floodlight 20 TV camera 30 Image processing section 31 Molded product image extraction section 32 Inspection Department 33 Control section 331 Light projection angle control section 332 Laser light source control section 40 Light projection angle adjustment section 42 Motor 50 Laser light source section 52 Laser diode head 100 Molded product

Claims (2)

[Claims] Claim 1: Consisting of a plurality of light emitting units, the irradiation unit irradiates the molded product with light, and the imaging unit acquires an external appearance image of the molded product, and the imaging unit comprises a plurality of light emitting units, and includes an irradiation unit that irradiates the molded product with light, and an imaging unit that acquires an external appearance image of the molded product, and an image capturing unit that acquires an external appearance image of the molded product based on the external appearance image. In a molded product appearance inspection device that determines quality, a plurality of divided areas are set in advance in the external appearance image, the illuminance of each divided area is detected, and the illuminance difference between each of the detected plurality of divided areas is detected. a control unit that generates a control signal based on the control signal; a first adjustment unit that adjusts a light projection angle of the irradiation unit to the molded product based on the control signal; and a plurality of light projecting units based on the control signal. and a second adjustment section that adjusts the amount of light emitted from each of the parts. 2. The molded product appearance inspection apparatus according to claim 1, wherein the control means calculates an illuminance difference between vertically divided regions among the plurality of divided regions, and
a function of generating a first control signal for controlling the adjustment section, and controlling the second adjustment section by calculating an illuminance difference between horizontally divided regions among the plurality of division regions. 1. An appearance inspection device for a molded product, characterized in that it has a function of generating a second control signal.