Measuring device for the length of repeat

摘要

The actual length of the rapport (repeat of the pattern) (print image spacing) is determined as the material web runs. The measuring point can be fixed as required. Pulses whose increment corresponds to a known advancement in length of the material are picked up at the measuring point from the running material by means of an appropriate sensor. In addition, pulses are generated in time with the print image itself, by scanning print marks or with the aid of a stroboscope. By counting the length increment pulses under the control hereof, numerical information is obtained on the actual length of repeat at the measuring point. The information can be used for display, recording or control. In this case, it is also possible to integrate over a plurality of print images in order to increase the measurement resolution or the averaging.