ApplicationNo. 483433 filed on 06/26/1974
US Classes:369/44.24, Means to mask or shield a portion of the beam365/124, Diffraction369/109.01, Diffractive storage medium information element369/112.28, Prism369/44.37, Plural incident beams369/44.42Beam or detector is not rectangular or circular
ExaminersPrimary: Hecker, Stuart N.
Attorney, Agent or Firm
Foreign Application Priority Data1973-06-29 FR
AbstractThe present invention relates to the optical read-out of a diffractive track carried by a data carrier. The object of the invention is an optical read-out device in which concentrated illumination of the track is effected by at least two collateral read-out spots straddling same, in order to produce a track eccentricity signal by subtraction of the voltages furnished by two groups of photo-electric transducers sensitive to the spread in the beams which form said spots.