Patent ID: 7552851

Claim:
A transport apparatus for a medium taking the form of a strip having perforation hales, the apparatus including a device for determining the transport speed of the medium, the device including a linear ray sensor extending along the transport direction and having. a combined length at least as long as one perforation hole and the distance between two perforation holes in the medium transport direction for imaging a selected portion of the medium encompassing at least a pair of spaced perforation holes along the transport direction and a region between said pair of perforation holes, comprising: means for illuminating at least the selected portion of the medium; and a signal processing circuit connected to the linear array sensor for determining the transport speed of the medium from the output signals from the linear ray sensor, wherein the signal processing circuit identifies characteristic intensity patterns associated with at least the pair perforation holes and the region between perforation holes and calculates the transport speed of the medium from the displacement of the intensity pattern between a first read-out instant of the linear ray sensor and a subsequent read-out instant and a read-out clock rate.