Web length measurement, of webs fed to a printing press on different planes, has a single meter for two adjacent webs

摘要

For the measurement of the lengths of webs fed to a printing press, at different levels, a number of meters are aligned across their direction of travel with a single meter for at least two webs. The measurements, at the web side edges, are in a single- or two- or three-dimensional optical action, with triangulation and structured surface illumination using photogrammetry.