Abstract: A reflected light barrier is provided which includes a light source and a transmitting lens located for transmitting light from the light source along a beam path having a transmitting axis. A retroreflector is positioned for receiving the light transmitted by the transmitting lens and retroreflects the transmitted light. A light detector is disposed on the same side of the retroreflector as the light source. A receiving lens having a receiving optical axis is disposed in front of the light receiver for collecting a portion of the retroreflected light and focusing the portion of retroreflected light onto the light detector. The transmitting lens and the receiving lens are arranged next to one another. An optical device is disposed along the beam path between the transmitting lens and the receiving lens for transmitting and redirecting the transmitted and retroreflected light so that an increased portion of retroreflected light is oriented onto the receiving optical axis of the receiving lens.

Abstract: A light deflector used for tracking a spiral information track alternately and periodically interrupted by data blocks and guide segments arranged within sectors of a rotating record carrier. The light deflector is controlled during the first turn of the information track by a slow analog light deflector having a small stroke and is controlled during the remainder of the recording by a digital light deflector control device having a relatively large stroke.

Abstract: An optical storage system for the simultaneous or random storage of digital information in a plurality of channels, comprising a rotating storage disc which is scanned by a light beam. The digital information of each channel is stored in points along a spiral track comprising interruptions. A concentrical guide track is associated with each channel. The light beam being focussed onto both tracks of each channel for optical addressing. The light beams of all channels are controlled via deflection systems so that, during the interruptions, they are briefly directed onto the guide tracks while following the spiral tracks. From the radial deviation of the moving disc, measured by way of a detector system, control signals are derived by the deflection systems to compensate for undesired radial motions of the spiral-shaped tracks.