In the realm of industrial machine vision, where precision and efficiency are paramount, it is difficult to emphasize the importance of controlled lighting in any imaging system. Lighting plays a pivotal role in a successful system and unlocking its full potential. 100% of the information contained in the images for analysis, is ultimately provided by the lighting. This means that correct lighting is a necessity and a critical factor that significantly impacts the accuracy, reliability, and overall success of an application. In this article, we delve into the importance of lighting and explore essential steps to consider when utilizing it for industrial machine vision applications.
Enhancing Clarity and Contrast:
One of the primary functions of lighting in machine vision is to enhance clarity and contrast of important features, but also to de-emphasize or eliminate irrelevant features that are not important to the inspection task. This is achieved by optimizing the illumination specifically for the job and not just produce an image that looks good to the human eye. Correct lighting eliminates shadows, reduces glare, and ensures consistent brightness, enabling machine vision algorithms to robustly segment the important features in an image and make accurate decisions based on the captured visual data.
Ensuring Uniform Illumination:
Having uniform illumination across the entire field of view is the key to consistent and reliable results. Uneven lighting leads to inconsistent results dependant on position in the image, making it challenging to consistently detect fine details or identify anomalies accurately. Achieving truly uniform illumination is not trivial. LEDs are now used in 99% of industrial lighting, thus manufacturers must ensure they only use LEDs with very consistent intensity and they must select appropriate quality diffusers/polarisers/lensing/light control film etc. The longevity of the output performance of a machine vision light is another critical consideration which involves correct heat management. Most machine vision systems have long service life expectations which can be difficult to achieve.
Adapting to Application Requirements:
Different industrial machine vision applications have varying lighting requirements. It is crucial to consider the specific needs of each application and select lighting accordingly. Factors to consider include the type of objects being inspected, their surface properties, required resolution, color fidelity, and desired imaging speed. Whether it’s high-speed production lines, precise measurement tasks, or intricate surface inspections, matching the lighting to the application’s unique demands is key to success, achieving reliable and repeatable inspection results.
Considering Lighting Techniques:
Industrial machine vision applications often require specialised lighting techniques to address specific challenges. Some common lighting techniques include:
a. Ring Lighting: Conveniently positioned around the camera lens, providing uniform illumination from the position of the camera, ideal general-purpose lighting.
b. Darkfield Lighting: Used to highlight edges and surface imperfections or defects that are not clearly defined under normal lighting conditions.
c. Backlighting: To produce a silhouette of the object, ideal for looking at fill levels in bottles or elements inside glass bulbs.
d. Coaxial Lighting: Minimizes reflections (of the camera) and shadows by directing light along the same axis as the camera lens.
e. Dome Lighting: Providing diffuse, uniform illumination from all directions, ideal for capturing images without shadows or inspecting concave/convex objects.
f. Polarized Lighting: Reduces reflections and enhances contrast, especially on glossy or reflective surfaces.
Adapting to Environmental Factors:
Industrial environments can be harsh and demanding. When selecting lighting for machine vision applications, it is essential to consider environmental factors such as temperature, humidity, vibrations, and potential exposure to dust or chemicals. Opting for industrial lighting solutions with appropriate IP ratings that are designed to withstand these conditions ensures long-term reliability and reduces maintenance needs, minimizing disruptions to production processes.
Collaborating with Experts:
Navigating the complexities of lighting for machine vision applications can be daunting. At MultiPix Imaging, we can provide expert advice on lighting products, recommending suitable lighting techniques and products to ensure optimal performance for your system. View our lighting range.
In the realm of industrial machine vision, lighting is a silent hero that significantly impacts the accuracy, reliability, and success of imaging systems. As well as establishing the appropriate lighting technique, considerations also include environmental factors and seeking expert advice to harness the power of lighting unlocking the full potential of the machine vision system. Embracing the crucial role of lighting leads to enhanced precision, improved quality control, and increased productivity, propelling businesses towards greater success in the modern manufacturing landscape.
If you are looking for advice to enhance your machine vision system, our expert team is here to help lead the way.
Get in contact with us: 01730 233332