Optoelectric device for the recognition of contrast marks

An optoelectronic device for recognizing a mark having a defined contrast pattern, comprising:

• a transmitting element for emitting a beam of transmitted light that is passed over the mark, the transmitted light beam having a spatial distribution of intensity and a corresponding frequency spectrum at a location of the mark;
• a receiving element for receiving a received beam of light reflected from the mark and producing an analog received signal which exhibits an amplitude modulation dependent on the contrast pattern of the mark and on the spatial distribution of intensity of the transmitted light beam at the location of the mark;
• an n-bit analog-to-digital converter having a word width (n) greater than one connected to the receiving element for receiving the analog received signal and converting the analog received signal into a digital received signal;
• and
• a digital filter connected to the n-bit analog-to-digital converter for receiving the digital received signal and having a transmission characteristic which is essentially equivalent to an inverse of a frequency spectrum of the spatial distribution of intensity of the transmitted light beam at the location of the mark for outputting a digital signal that has transition points corresponding to transition points in the contrast pattern of the mark.