(under the class definition) Subject matter including structure to establish and determine the proper focal position of a concentrated light source with respect to optical elements, such as a parabolic light reflector or a lens; or to indicate the coincidence of a concentrated light source at the focal point of a lens or parabolic reflector; or the deviation from such coincidence.
SEE OR SEARCH THIS CLASS, SUBCLASS:
122, for head light focusing with direction or pattern determining.
SEE OR SEARCH CLASS
362, Illumination,
285+, for lamps with a built-in sighting device for focusing the filament of the lamp with respect to the optical light projection elements of the lamp.
