(under subclass 16) Subject matter wherein the system decides correct direction for a collection of parallel rays.
SEE OR SEARCH CLASS
250, Radiant Energy, various subclasses for methods and apparatus involving radiant energy.
342, Communication: Directive Radio Wave and Devices (e.g. Radar, Radio Navigation), various subclasses for transmission or reception of radio wave energy for obtaining or utilizing information.
359, Optics: System (Including Communication) and Elements, various subclasses for optical elements and optical systems not elsewhere classified.