| 摘要 |
To recognise markings in the form of dashes during a relative movement between the markings and an opto-electronic scanning device, the opto-electronic scanning device is provided with two scanners (A1, A2) which are arranged to be slightly offset with respect to one another in the direction of scanning. The output signals (AB1, AB2) of the scanners (A1, A2) are present, on the one hand, at a differential stage (D) generating difference signals (DI) and, on the other hand, at a summing stage (S) generating sum signals (SU). When a sum signal (SU) occurs and, at the same time, a difference signal (D) exhibits a zero transition, an evaluating stage (AW) generates a signal associated with the marking. <IMAGE> |
