Abstract: To follow and inspect a common edge between two sheet metal blanks which are to be welded together, a line pattern is projected across the edge by a projector and is imaged by a camera. The image captured is analyzed in order to derive from the trace of the lines information on the gap between the blanks, or on the track of the edge. The pattern projected has several lines with different light intensities. When the photographed image is processed, it is then possible—even if there is variation in the reflection characteristics of the sheet metal blanks—to select a line which is neither too faint nor too bright in the image obtained and which can therefore be used for meaningful analysis.

Abstract: In the welding together of sheet-metal blanks an image of a line pattern projected across the weld seam is captured by a camera and evaluated to inspect the weld seam. For improved inspection, a sidewards view of the weld seam is obtained, eg. by means of a prism, in addition to the view from above. This affords an improved and more accurate inspection of the weld seam.

Abstract: To photograph the mouth region of a bottle, a light-emitting surface is arranged below the mouth region to be photographed. The light-emitting surface is illuminated by means of an illuminating device and the image of the illuminated mouth region is directed to a camera by a mirror arrangement (5,6,11). The light-emitting surface makes it possible to image the mouth region in transmitted light, facilitating detection of defects and soiling in the mouth region from the interpretation of the image recorded by the camera.