Benefits of color line-scan cameras touted

During the Vision 2004 trade fair (October 19–21, Stuttgart, Germany), Hardy Mehl of Basler Vision Technologies described innovations in color line-scan cameras. Mehl predicted a bright future for the cameras, with resolutions extending beyond 8 kpixels and rates moving well beyond 160 Mpixels/s. Mehl described two color line-scan approaches—prism and trilinear. He explained that prism cameras employ three sensors—one each for red, green, and blue—and require a prism to split the incident light into its three components. Trilinear cameras, he said, use a single, three-line sensor, but each line has a different field of view that must be compensated for via spatial correction performed in a camera or frame grabber.

Then he addressed the question, "Which is better?" by saying, "It depends!" Trilinear units, Mehl explained, are suitable for price-sensitive applications as well as those requiring cameras having low weight and compact size. Trilinear cameras can be eight to 10 times more compact than prism cameras and can require expensive, custom lenses. But prism cameras support higher line rates (greater than 10 kHz) and are adept at applications involving falling targets or targets that otherwise can't be definitively aligned with the camera.