Abstract: There is provided an optical scanner collecting information from an original by means of sweeping scan. The scanner comprises a memory working as a buffer between the scanner and an external unit receiving data from the scanner. According to the invention and in order to reduce mechanical vibrations from displacement means displacing the original relative to the scanner at a feed rate, the scanner comprises control means for controlling the magnitude of the feed rate. The feed rate is adjusted according to a procedure comprising a first step: if the memory has capacity for a higher data rate and if said feed rate is less than a preferred value, then said feed rate is increased by a value that is a fraction of said preferred value. Further, the scanner may comprise a data processor for maintaining a preferred line resolution while the feed rate is below the predetermined value.