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Views: 0 Author: Site Editor Publish Time: 2025-09-02 Origin: Site
In modern manufacturing and automated inspection, industrial cameras have become a key component of machine vision systems. Whether in electronics manufacturing, automotive parts inspection, food packaging, or medical device testing, industrial cameras, lenses, and lighting all play a crucial role. Together, they determine the system's image quality and inspection accuracy. Proper parameter selection, lens pairing, and effective lighting methods, tailored to specific requirements, directly impact the accuracy and reliability of inspection results. This article will cover industrial camera classifications, key parameters, lens pairing principles, selection considerations, and lighting types and methods to help users better understand the application of machine vision equipment.
Industrial cameras are primarily categorized into area scan cameras and line scan cameras based on their imaging method:
Area Scan Camera
Area scan cameras capture images by capturing several lines at a time and outputting them as frames. They have a wide range of applications, such as measuring area, shape, size, position, and even temperature. Using a two-dimensional pixel array to capture the entire image, they are suitable for inspecting stationary or slow-moving objects. Their advantages lie in intuitive imaging and ease of operation.
Line Scan Camera
Line scan cameras feature high scanning frequency and high resolution. They scan "line" pixels line by line, stitching together a complete image. They are commonly used in high-speed production lines or large-format inspection applications, such as paper, fabric, lithium battery electrodes, and PCB boards. Their advantages include high resolution, fast speed, and zero image distortion.
Industrial cameras can also be categorized based on data transmission methods, using interfaces such as USB 3.0, GigE, Camera Link, and CoaXPress. The USB 3.0 interface is simple and easy to use, GigE has a long transmission distance, and Camera Link and CoaXPress are more suitable for high-speed inspection scenarios with extremely high data bandwidth requirements.
During the selection process, key camera parameters determine imaging performance:
Resolution: The number of pixels a camera can capture. This affects the image detail and measurement accuracy, determining whether details of the inspected object can be clearly captured. For example, detecting tiny scratches requires a high-resolution camera; otherwise, it's easy to miss them.
Frame rate: This refers to the number of images a camera captures per second. It is closely related to production cycle times. High-speed production lines must use high-frame-rate cameras to avoid incomplete inspections due to frame dropouts. High-frame-rate cameras are suitable for capturing and analyzing fast-moving objects.
Pixel size: The pixel size is the area of each pixel. Larger pixels have greater sensitivity and lower noise; smaller pixels have higher resolution, but require more stringent lighting conditions.
Dynamic range: This represents the range of light signals a camera can detect. For fixed cameras, the dynamic range is a fixed value that does not change with external conditions. It measures the camera's imaging capabilities when both bright and dark areas are present. This is also important for inspecting metal surfaces and reflective objects. Interface bandwidth: Ensures that captured images can be transmitted to the industrial computer in a timely manner to avoid delays or insufficient bandwidth that could affect inspection results.
These parameters vary across different application scenarios. For example, the 3C electronics industry prioritizes high resolution and high frame rates, while logistics sorting prioritizes high-speed transmission and real-time performance.
The camera and lens are an inseparable pair, and a proper pairing maximizes performance:
Resolution Matching: The optical resolution of the lens must match the camera's pixel density. Using a high-pixel camera with a low-resolution lens will significantly reduce image quality.
Target Coverage: The lens must cover the entire sensor surface; otherwise, problems such as vignetting and incomplete imaging will occur.
Focal Length Selection: Based on the size of the inspection object and the camera installation space, select a lens with an appropriate focal length to ensure the required field of view.
Specialty Lenses: For example, telecentric lenses are often used for high-precision dimensional measurement to avoid perspective errors, while lenses with large clear apertures are suitable for imaging in low-light environments.
For example, lithium battery appearance inspection often requires a high-resolution industrial camera paired with a telecentric lens to accurately measure dimensions and identify extremely subtle defects.
In practical applications, camera selection should consider the following factors:
Inspection object characteristics: Is it inspecting dimensions, surface defects, or barcode recognition? Different tasks require different resolution and imaging speeds.
Production line speed: The faster the line, the higher the camera frame rate and interface bandwidth requirements.
Operating environment: Dust, vibration, humidity, and temperature fluctuations should be considered. For example, for outdoor or high-humidity environments, choose an industrial camera with an IP67 rating.
System compatibility: The camera must work seamlessly with the lens, lighting, acquisition card, and software to ensure stable operation of the entire system.
Light source is a crucial part of machine vision. Reasonable selection of light source can greatly improve imaging effect:
Ring light sources: Provide uniform illumination, suitable for surface inspection and defect detection.
Bar light sources: Cover large workpiece surfaces and are commonly used for inspecting packaging, glass, or metal surfaces.
Backlight light sources: Highlight workpiece contours and are used for dimensional measurement and foreign object detection.
Coaxial light sources: Suitable for inspecting reflective surfaces, ensuring that details are not obscured by strong light.
Point light sources: Focus illumination on a small area and are used for inspecting localized details.
Not only is choosing the right light source crucial, but how you use it is also crucial. Common lighting methods include:
Front lighting: Evenly illuminates the entire workpiece, suitable for overall observation.
Side lighting: Highlights texture and surface defects such as scratches and dents.
Back lighting: Enhances outlines and edges, widely used for dimensional measurement and foreign object detection.
Multi-angle lighting: Suitable for complex workpieces, reducing blind spots caused by shadows and reflections.
For example, in metal part inspection, side lighting effectively highlights surface flaws, while in glass inspection, back lighting can better highlight cracks and foreign objects.
In machine vision inspection, industrial cameras, lenses, and lighting together form a complete visual system. Reasonable camera parameter configuration, scientific lens selection, and proper lighting methods directly determine the accuracy and stability of inspection results. In practical applications, Zhixiang Shijue comprehensively considers the selection and combination of models based on the inspection task, production line speed, and environmental factors, thereby building an efficient and stable visual inspection system.
With the integration of AI and deep learning algorithms, the functions of industrial cameras will go beyond "imaging" and will gradually develop towards intelligent recognition and data analysis. This means that future industrial vision systems will play an even greater role in the manufacturing industry, providing solid support for companies to reduce costs, increase efficiency, and improve yield rates.
