Patent ID: 7369354

Claim:
A device for storage of data on data carriers accommodated in cassettes, with a magazine, having receptacles for the cassettes, and with a robot unit to change the cassettes from the receptacles or into the receptacles, in which the magazine and the robot unit are movable in controlled fashion relative to each other, in order to position the selected receptacle and the robot unit for the change, wherein an optical sensor unit, on the one side, and a light guide element, on the other, are provided for positioning, one of which is arranged on the robot unit and the other on each receptacle, the sensor unit has at least one light transmitter with a light exit and a light receiver with a light entrance, in which the light exit and the light entrance are spaced from each other, the light guide element has at least one entrance and one light exit, having the same mutual spacing as the light entrance and light exit of the sensor unit, in the change position of the receptacle in the robot unit, the light entrances and light exits of sensor unit and light guide element are congruent, so that the light emitted from the light exit of the light transmitter impinges on the light entrance of the light guide element, is deflected in the light guide element to its light exit and is emitted from this light exit to the light entrance of the light receiver, and receiving of the light emitted from the light transmitter in light receiver is used as a positioning signal.