Company A provides parts to a major automobile manufacturer, with an established record for large components. They considered building a more accurate and efficient appearance inspection system in line with the recent demand for higher quality standards and shorter delivery periods. However, they had the problems unique to large parts.
- Variations between systems is a concern as multiple vision systems will be simultaneously be controlled.
- Purchasing many vision systems could be cost.
After the introduction of "4D High Resolution" lenses
- Variations between systems were suppressed by using our lenses, from which variations have been eliminated.
- The number of cameras was reduced by using lenses that have a wide field of view and uniform resolution performance.
Issue 1: To capture uniform images with more than 20 vision systems
Problem 1: Variations in captured images due to differences in lens performance and the man-hours required to correct such variations
Large components manufactured by Company A are to be attached to various parts of an automobile. The shapes and sizes vary depending on where they will be attached and the type of automobile. In order to carry out appearance inspections efficiently, they initially planned to inspect components by simultaneously shooting the entirety of each component. Including left, right, top and bottom or other angles in some cases, using multiple vision systems. For the inspection of large parts, the inspection system needed more than 20 vision systems. However, the lenses they used varied in performance, causing variations in the results of the image inspections. They took time repeatedly making adjustments to obtain consistent defect detection ability, but their efforts were to no avail.
Issue 2: To reduce cost by decreasing the number of vision systems
Problem 2: A uniform image cannot be obtained when the shooting area is expanded.
Building a new inspection system that suppressed differences in performance among vision systems and at the same time reducing the management man-hours and cost by reducing the number of vision systems was the goal. However, in order to inspect large parts in the same way as before with fewer vision systems, it was necessary to expand the shooting area using a wide-angle lens. But that's not all. This also required high performance lenses capable of detecting the smallest irregularities in the edges of the image frame.
The keys to solving these issues were...
Elimination of variations in resolution performance between lenses and expansion of the shooting area.
In order to eliminate variations in image inspection results and reduce the number of cameras, Company A decided to introduce the latest high resolution cameras. Thinking the key to success is in the selection of the lenses, they consulted the supplier of the cameras they were considering. The camera manufacturer recommended Fujifilm's machine vision camera lenses with "4D High Resolution" performance, saying "those lenses will bring the best out of the cameras."
Solution of Issue 1: Adoption of lenses with little variation between individual lenses
In inspections using multiple vision systems, the inspection results will vary unless all the systems demonstrate the same performance. In particular, lenses need special attention as they tend to show differences in quality. Company A really wanted quality-assured lenses that do not have any individual differences. All Fujifilm "4D High Resolution" lenses for machine vision cameras are strictly checked by inspection devices we developed ourselves in order to suppress lens-to-lens variations in terms of performance. In addition, all lenses are given serial numbers for thorough quality control of each lens. They are also capable of suppressing resolution degradation when the shooting distance or aperture is changed, and successfully reduced variations in the image inspection results in the case of Company A, where the cameras are installed at several locations with different conditions. As these lenses deliver uniform performance, the time it takes to adjust the inspection system can also be shortened, easing the burden on workers.
Generally, lenses are designed to have the best resolution at a predetermined standard shooting distance (design distance). Therefore, the edges of the image may become blurry when the distance is changed. This trait tends to stand out, particularly in the case of wide angle lenses. Floating design technology is used in "4D High Resolution" lenses. The lens elements are configured into front and rear groups, and only the lens elements behind the iris move to focus. This restrains the drop in resolution caused by changing shooting distances. In addition, misalignment of the axis of the lenses is eliminated by aligning the entire lens constructions with micrometer-level adjustments during assembly. Fujifilm lenses maintain high resolution across the image, enabling the area covered by each lens to be expanded. As a result, Company A was able to significantly reduce the number of vision systems it needed.
The HF6XA-5M series, featuring "4D High Resolution" performance, maintains a high level of resolution performance from the center of the image all the way to the edges, despite the fact that they are wide-angle lenses with a 6 mm focal length. Therefore, it is the most suitable for the inspection of large parts as in the case of Company A. At Company A, some vision systems had to be installed at a distance from the parts to be inspected. For Company A, the key reason for introducing the HF6XA-5M was that they boast high resolution performance even at the edges while ensuring a wide shooting area. In addition, strict quality checks and management of all lenses using serial numbers also played a part in earning their trust.