Patent ID: 6275349
Filing Date: 2001-08-14
Classification: G11B

Abstract:
An improved servo system having a combination head having a plurality of magnetic heads that read and write data in a magnetic side of a medium, the improvement comprises:a light source array attached to the plurality of magnetic heads, the light source array emitting an array of incident light beams;a plurality of optical servo tracks disposed on the magnetic side of the medium, the plurality of optical servo tracks reflecting the array of incident light beams to produce an array of reflected light beams;a bi-cell photo detector array attached to the plurality of magnetic heads, the bi-cell photo detector array converting the individual reflected light beams of the array of reflected light beams into an array of photo currents;a beam splitter array positioned between the plurality of optical servo tracks, the light source array and the bi-cell photo detector array, the beam splitter array being oriented to direct the array of incident light beams onto the plurality of optical servo tracks and to direct the array of reflected light beams onto the bi-cell photo detector array;a lens array positioned between the plurality of optical servo tracks and the beam splitter array to focus each individual incident light beam of the array of incident light beams onto a respective one optical servo track of the plurality of optical servo track, and focus each individual reflected light beam of the array of reflected light beams onto a respective one bi-cell photo detector of the bi-cell photo detector array;a differential amplifier array electrically connected to the bi-cell photo detector array, the differential amplifier array amplifying the array of photo currents to produce an array of error signals indicative of the alignment of the plurality of magnetic heads with the medium; and a circuit electrically connected to the differential amplifier array, the circuit combining the array of error signals to produce a position error signal.