VCO SERIES - CO-AXIAL BOX LIGHT
About Co-Axial Lighting Selection (Effective Field of View and Illumination Stereoscopic Angle) When a workpiece with high reflectance is inspected with co-axial lighting, the area that appears bright is called the effective field of view. The effective field of view of co-axial lighting is related to the size of the light emitting area of the lighting, the distance from the camera to the workpiece (WD) and the distance from the lighting to the workpiece (LWD). (e.g., long WD = narrower angle of view → larger effective field of view, long LWD → smaller effective field of view) Since the effective field of view varies with the size of the light emitting area and LWD, set the field of view with a generous margin, taking into account the decrease in brightness at the periphery. To obtain a large effective field of view, move the lighting closer to the workpiece to increase the effective field of view, but there is a disadvantage that it is difficult to obtain the contrast of unevenness. Relationship between lighting size, angle of view, and effective field of view
In order to image the entire field of view brightly, lighting with a light emitting area larger than the field of view is necessary. Furthermore, the use of a lens with a wide angle of view requires lighting of a larger light emitting area. Differences in images caused by moving the lighting away from the workpiece
Sample
■ short LWD
■ long LWD
By moving the lighting away from the workpiece, unevenness becomes more noticeable. We will select the best solution for the customer’s issue, such as making scratches stand out or pear-shaped areas as inconspicuous as possible.
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