Visual inspection of surface scratches on electronic products

In the electronics manufacturing industry, product appearance quality not only affects brand image but also directly impacts customer experience and market competitiveness. Especially in the production of 3C electronics and precision structural components, minor scratches, abrasions, and dents on product surfaces are often difficult to assess consistently and uniformly through manual visual inspection. In high-paced production environments, manual inspection is also susceptible to fatigue and subjective judgment differences, leading to missed or incorrect inspections.

To improve the automation and standardization of electronic product appearance inspection, we conducted a machine vision inspection test project focusing on scratch recognition on electronic product surfaces, constructing a complete visual inspection process from signal triggering and optical imaging to software recognition.

System architecture and testing process

The testing system mainly consists of the following core components:

Sensor triggering module

Light source illumination system

Industrial camera and high-resolution industrial lens

Image processing and defect recognition software system

When a product enters the inspection station, the sensor first captures the position signal and sends a trigger command to the system, ensuring precise and controllable shooting timing and avoiding image blurring or acquisition offset caused by motion errors.

Subsequently, the light source system is designed with targeted lighting based on the product's material and surface reflectivity. Since electronic product casings typically have different surface treatments such as spraying, brushing, polishing, or plating, scratches appear significantly different under different lighting angles. Therefore, in this test, we enhanced the grayscale contrast between the scratches and the background by adjusting the light source angle, brightness, and illumination method, making subtle defects more prominent.

Imaging and detail capture capabilities

In the imaging stage, an industrial camera, paired with a high-resolution lens, captures high-precision images of the product surface. By appropriately setting the working distance and optical parameters, the system can clearly reproduce the surface texture details, providing high-quality raw images for subsequent algorithmic analysis.

In actual test images, even minute scratches that are difficult to detect with the naked eye at first glance can be clearly presented after magnifying the image, significantly improving the visualization of defects. This high-precision imaging capability lays a solid foundation for automated appearance inspection.

Software recognition and intelligent judgment

After image acquisition, the inspection software performs intelligent analysis of the product surface. The system identifies and locates suspected scratch areas through image preprocessing, edge enhancement, and feature extraction algorithms. Simultaneously, it comprehensively judges the length, width, and contrast of defects based on set thresholds, achieving automated screening of scratch defects.

For defects of different severity, it can also perform hierarchical classification, supporting data statistics and result recording, providing data support for quality traceability and process optimization.

Test Results and Application Value

During testing, the system operated stably, with rapid signal trigger response and clear, continuous image acquisition. The vision system demonstrated excellent adaptability and recognition accuracy across electronic products with different surface treatment processes.

Compared to traditional manual inspection methods, this vision inspection solution offers the following advantages:

Improved inspection efficiency to meet the demands of high-speed production lines

Reduced labor costs and subjective judgment errors

Enhanced inspection consistency and data traceability

Supports integration with automated production line systems for intelligent sorting

Through this visual testing project for surface scratch detection on electronic products, we further validated the application value of machine vision in the field of appearance quality control. In the future, we will continue to optimize optical structure design and algorithm capabilities, expanding inspection applications in more complex working conditions and multi-material scenarios, providing the electronics manufacturing industry with more stable, accurate, and efficient vision inspection solutions.