A method for detecting defects in a transparent injection molded device

Abstract

The application discloses a transparent injection molding device defect detection method, which comprises high-transparency glass, a surface light source arranged below the high-transparency glass and a pattern acquisition device arranged above the high-transparency glass. The detection steps are as follows: S1: the transparent injection molding device is placed on the high-transparency glass, and the surface light source is turned on; S2: light passes through the transparent injection molding device; S3: the light makes the profiles of different heights of the transparent injection molding device to be displayed after passing through the transparent injection molding device; S4: the image acquisition device realizes profile data acquisition of different heights, and a multilevel image set is obtained; and S5: an image comparison module, the image comparison module has a standard product profile sample, the multilevel image set is compared with the standard product profile sample, and a defect factor distribution position of the transparent injection molding device is obtained. Through cooperation of the high-transparency glass and the surface light source, the light can pass through the body of the transparent injection molding device, blind areas in detection are avoided, and the profiles of different heights and different levels can all display shapes.

Description

Technical Field

[0001] This invention relates to the field of injection molded product testing, and in particular to a method for detecting defects in transparent injection molded parts. Background Technology

[0002] The advantages of injection-molded parts are: low price, light weight, durability, easy cleaning, and availability in various colors, making them both practical and aesthetically pleasing. Therefore, products using injection-molded parts often have a significant cost advantage.

[0003] Injection molded parts are used in IT products, medical devices, machinery, agricultural machinery, and more. They are widely used in industrial and agricultural production due to their high quality and low cost. Currently, injection molded parts are primarily used in the ever-growing number of electronic products. As market demand continues to expand, the injection molding industry is also growing, undergoing a process of natural selection amidst increasingly fierce competition.

[0004] With the further development of the social economy and the expansion of market demand, the injection molding industry will continue to flourish, and the demand for defect detection equipment is also increasing daily. Especially for transparent injection molded parts, due to their light transmittance and scattering properties, existing detection methods cannot meet the requirements for satisfactory optical inspection. Defects such as short cut lengths, bubbles, edge chipping, and deformation are technical challenges in the industry.

[0005] For larger defects in injection molded parts, the industry can use a detection scheme with a telecentric lens and a dome light source or coaxial light source between the injection molded part and the light source in the same direction. This allows the injection molded part to be displayed on the black and white camera software interface. However, the defects on the edge and inside of the injection molded part are not obvious, resulting in low contrast for a series of smaller (inconspicuous) dents and defects. This significantly increases the over- and under-detection rates, which is not conducive to expanding production capacity. Summary of the Invention

[0006] The main objective of this invention is to propose a defect detection method for transparent injection molded parts, aiming to solve the aforementioned technical problems.

[0007] To achieve the above objectives, this invention proposes a defect detection method for transparent injection molded parts, comprising high-transparency glass, a surface light source disposed below the high-transparency glass, and a pattern acquisition device disposed above the high-transparency glass. The detection steps are as follows:

[0008] S1: The transparent injection-molded part is placed on high-transparency glass, and the surface light source is turned on;

[0009] S2: Light passes through the high-transparency glass, covering the entire transparent injection molded part, while the light also passes through the transparent injection molded part;

[0010] S3: Light passes through the transparent injection molded part, making its contours at different heights visible;

[0011] S4: The image acquisition device acquires contour data at different heights, obtains a multi-level image set, and analyzes the multi-level image set through the preprocessing module;

[0012] S5: Image comparison module, which has a standard product outline sample, a multi-level image set compared with the standard product outline sample, and obtains the distribution location of defect factors of transparent injection molded device.

[0013] Specifically, the multi-layered image set includes N+1 layers of independent images of the transparent injection molded device, which are then decomposed into N+1 layered projected images; the standard product outline sample includes N+1 layered standard images.

[0014] Specifically, the preprocessing module filters out interfering factors, which include reflection, strong light, and unclear outlines.

[0015] Specifically, the defect factors include the length of the shear cut, air bubbles, edge chipping, and deformation.

[0016] Specifically, the image acquisition device is a monochrome camera and a corresponding telecentric lens.

[0017] Specifically, the exposure parameters of the black and white camera are 30ms-60ms.

[0018] Specifically, the independent image is a single horizontal height image or a cross-height image.

[0019] Specifically, the multi-layered image set includes an inner contour and an outer contour.

[0020] Specifically, the light intensity of the surface light source can be adjusted, and a multi-layer image set with different light intensities can be acquired.

[0021] Advantages of the technical solution of this invention:

[0022] 1. By combining high-transparency glass and surface light source, light can pass through the transparent injection molded device body, avoiding blind spots in detection, and the shape can be displayed for contours of different heights and levels;

[0023] 2. By displaying the image of the transparent injection molded part through the image acquisition device and comparing it with the outline sample of the standard product, the defects that appear inside the transparent injection molded part can be obtained, such as the length of the shearing cut, air bubbles, edge chipping, deformation and other defects, which form a sharp contrast with the overall area of ​​the transparent injection molded part.

[0024] 3. In actual operation, the multi-level image set at different heights is further differentiated into N+1 levels of images, so that the independent image is decomposed into layered projection images, which can make the comparison of image defects more precise.

[0025] 4. This testing method can be applied to transparent injection molded products of different heights. It is a replicable and learnable model, and the testing method is simple. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the detection process;

[0027] Figure 2 This is a schematic diagram showing the inspection of an object after perspective.

[0028] Figure 3 To detect the side view of the item. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0031] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0032] like Figures 1 to 2 As shown, a method for detecting defects in transparent injection molded parts includes high-transparency glass, a surface light source disposed below the high-transparency glass, and an image acquisition device disposed above the high-transparency glass.

[0033] Testing steps:

[0034] S1: The transparent injection-molded part is placed on high-transparency glass, and the surface light source is turned on;

[0035] S2: Light passes through the high-transparency glass, covering the entire transparent injection molded part, while the light also passes through the transparent injection molded part;

[0036] S3: Light passes through the transparent injection molded part, making its contours at different heights visible;

[0037] S4: The image acquisition device acquires contour data at different heights, obtains a multi-level image set, and analyzes the multi-level image set through the preprocessing module;

[0038] S5: Image comparison module, which has a standard product outline sample, a multi-level image set compared with the standard product outline sample, and obtains the distribution location of defect factors of transparent injection molded device.

[0039] 1. By combining high-transparency glass and surface light source, light can pass through the transparent injection molded device body, avoiding blind spots in detection, and the shape can be displayed for contours of different heights and levels;

[0040] 2. By displaying the image of the transparent injection molded part through the image acquisition device and comparing it with the outline sample of the standard product, the defects that appear inside the transparent injection molded part can be obtained, such as the length of the shearing cut, air bubbles, edge chipping, deformation and other defects, which form a sharp contrast with the overall area of ​​the transparent injection molded part.

[0041] 3. In actual operation, the multi-level image set at different heights is further differentiated into N+1 levels of images, and the independent images are decomposed into layered projection images, which can make the comparison of image defects more precise.

[0042] Specifically, the multi-layered image set includes N+1 layers of independent images of the transparent injection molded device, which are then decomposed into N+1 layered projection images; the standard product contour sample includes N+1 layered standard images, which are obtained by displaying the inner and outer contours of different heights separately and then obtaining the defect factor through image processing.

[0043] Furthermore, the preprocessing module filters out interfering factors, such as reflections, strong light, and unclear outlines. When these interfering factors are present, the preprocessing module can remove them, either by comparing multiple images or by controlling the image acquisition device to re-acquire the image.

[0044] exist Figure 2 In this process, images from different altitudes are combined on the same latitude to obtain a multi-layered image set.

[0045] exist Figure 3In the above-mentioned first height, second height, third height and fourth height, the height position of the N+1 layered projection image can be referenced; of course, in specific embodiments, complex graphics can also be set to the first height, second height and third height of the inner / outer contour, etc.

[0046] Specifically, the defect factors include the length of the cut, air bubbles, edge chipping, and deformation. In this embodiment of the invention, for example, if an edge protrusion exceeds a predetermined threshold for a straight edge, it is judged as a defective product.

[0047] In this embodiment of the invention, the image acquisition device is a black and white camera and a corresponding telecentric lens. By moving the black and white camera and the telecentric lens up and down, the distance between the telecentric lens and the object being measured is adjusted so that the transparent injection molded device is clearly displayed in the black and white camera software window on the computer monitor. The exposure parameter of the black and white camera software is adjusted to 40ms.

[0048] Specifically, the exposure parameters of the black and white camera are 30ms-60ms.

[0049] In this embodiment of the invention, the independent image is a single horizontal height image or a cross-height image, that is, when segmenting the image, images at different locations can be segmented and set according to elements.

[0050] Furthermore, the multi-layered image set includes inner contours and outer contours.

[0051] In this embodiment of the invention, the light intensity of the surface light source can be adjusted, and a multi-layer image set with different light intensities can be obtained.

[0052] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for detecting defects in transparent injection molded parts, characterized in that, It includes high-transparency glass, a surface light source located below the high-transparency glass, and an image acquisition device located above the high-transparency glass. Testing steps: S1: The transparent injection-molded part is placed on high-transparency glass, and the surface light source is turned on; S2: Light passes through the high-transparency glass, covering the entire transparent injection molded part, while the light also passes through the transparent injection molded part; S3: Light passes through the transparent injection molded part, making its contours at different heights visible; S4: The image acquisition device acquires contour data at different heights, obtains a multi-level image set, and analyzes the multi-level image set through the preprocessing module; S5: Image comparison module, which has a standard product outline sample, a multi-level image set compared with the standard product outline sample, and obtains the distribution location of defect factors of transparent injection molded device; The multi-layered image set includes N+1 layers of independent images of the transparent injection molded device, which are then decomposed into N+1 layered projected images; the standard product outline sample includes N+1 layered standard images. The preprocessing module filters out interfering factors, which include reflection, strong light, and unclear outlines. The defect factors include the length of the shear cut, air bubbles, edge chipping, and deformation. The image acquisition device is a monochrome camera and a telecentric lens; the exposure parameters of the monochrome camera are 30ms-60ms.

2. The defect detection method for transparent injection molded parts as described in claim 1, characterized in that: The independent image is either a single horizontal height image or a cross-height image.

3. The defect detection method for transparent injection molded parts as described in claim 1, characterized in that: The multi-layered image set includes inner contours and outer contours.

4. The defect detection method for transparent injection molded parts as described in claim 1, characterized in that: The light intensity of the surface light source can be adjusted, and a multi-layer image set with different light intensities can be acquired.

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