As quality standards continue to rise across the manufacturing industry, inspection systems are expected to detect increasingly smaller scratches, contaminants, print defects, and other surface imperfections with greater accuracy. However, inspecting reflective materials such as aluminum, stainless steel, silicon wafers, and various films presents a significant challenge. Reflected illumination can create glare and overexposed areas, making critical defects difficult to detect. These unwanted reflections are one of the primary factors affecting image quality and the accuracy of image processing algorithms. As production lines continue to operate at higher speeds and inspection systems adopt higher imaging resolutions, the importance of advanced illumination technology and image acquisition has become greater than ever.
One of the greatest challenges in machine vision is the inspection of highly reflective materials. Aluminum, stainless steel, silicon wafers, metal foils, and glossy films naturally behave like mirrors, reflecting incident light directly back toward the imaging system. As a result, cameras capture not only useful inspection data but also unwanted reflections, which reduce image contrast and may obscure critical surface defects. This can cause images to appear washed out or produce localized bright areas that obscure critical inspection details. Under these conditions, fine scratches, scuff marks, contamination, printed characters, edge defects, and surface patterns may blend into the background, reducing inspection accuracy. In addition, uneven illumination and brightness variations can negatively affect image processing stability, increasing the risk of false positives or missed defects. As inspection speeds increase, correcting image quality after acquisition becomes increasingly difficult. High-quality images must therefore be captured at the source.
High-quality surface inspection depends on the optimization of multiple optical elements. As part of our CIS Line Scan Camera lineup, GPL series minimizes unwanted reflections generated by the inspection target while capturing only the information required for reliable inspection with high contrast. Rather than relying on external lighting, the optimized illumination system is integrated into the camera architecture. The illumination, lens, and camera are designed as a single imaging system, enabling stable, repeatable image acquisition even when inspecting highly reflective materials.
As a result, the system clearly captures:
allowing even subtle surface features to be inspected with greater clarity.
Photo
Scanned image of GPL series
Demonstration video of GPL series
Obtaining high-quality images requires much more than a high-performance image sensor. The overall optical system including illumination, light control, and working distance must be carefully optimized. When these elements are designed as a unified imaging system, unwanted reflections can be minimized while preserving the information required for accurate inspection. Since 2003, WHEC has specialized exclusively in the development and manufacturing of Contact Image Sensor (CIS). Leveraging decades of experience, we integrate the camera, optimized illumination, and lens into a single compact imaging system that delivers highly uniform, high-quality images, even when inspecting glossy or highly reflective materials.
As inspection requirements continue to evolve, manufacturers are faced with increasingly diverse inspection challenges. Semiconductor devices continue to shrink, printed electronics require finer image detail, battery materials demand higher inspection speeds, and production equipment is expected to become more compact without compromising performance. To meet these changing requirements, WHEC has further enhanced its unique, in-house illumination technology with the latest GPL Series CIS line scan cameras. This new GPL series further advances our proprietary technology, delivering improved image quality, higher resolution, and enhanced imaging performance for demanding machine vision applications. Where previous generations primarily focused on monochrome imaging, the latest models are also available in color. This expands inspection capabilities for applications requiring color differentiation, print verification, and surface color analysis.
Demonstration video of GPL series in color
The latest series is also used in demanding semiconductor inspection applications. Even highly reflective materials such as silicon wafers can be captured with excellent image uniformity while significantly reducing unwanted reflections. This enables clearer visualization of fine defects and surface conditions, supporting highly accurate wafer inspection.
Demonstration video of wafer surface imaging with GPL series
The latest series offers resolutions of up to 2400 dpi, enabling high-resolution imaging for increasingly miniaturized products and precision manufacturing applications. Its integrated compact design simplifies installation while reducing system footprint. In addition, working distances of up to approximately 30 mm provide greater flexibility for equipment layout and machine design. The system also supports stable high-speed inline inspection at up to 69 kHz (CoaXPress 2.0, 2400 dpi) without compromising image quality. To simplify system integration, multiple industrial interfaces are available, including CoaXPress, Camera Link, and additional interface options to match existing inspection equipment and machine architectures.
Every inspection application has unique requirements. Depending on the material being inspected, installation constraints, production speed, and system architecture, different camera specifications may be required to achieve optimal performance. For this reason, WHEC offers extensive customization of its CIS line scan cameras. Available customization options such as:
Whether the challenge involves excessive reflections from a particular material, limited installation space, or compatibility with a preferred industrial interface, our engineering team can configure each camera to meet the specific requirements of the application. This flexibility is one of the advantages of working with a manufacturer dedicated exclusively to CIS line scan camera technology.
If you are experiencing challenges with surface inspection of reflective materials—including glossy films, semiconductor wafers, metal foils, aluminum, stainless steel, or other high-reflectivity materials—please feel free to contact us.
Our team will work with you to recommend the optimal CIS line scan camera configuration for your inspection application. Discuss your challenges with us: WHEC
For further details or questions regarding product characteristics, please call or send us an inquiry.
You are more than welcome to ask for samples! Feel free to ask about requests for samples or if there are any other questions.
