(under the class definition) Subject matter wherein a structure transmits light energy where all transmitted rays travel in essentially straight lines (i.e., without intentional deviation as, for example, by reflection, refraction or diffraction) and without significant attenuation (i.e., without being filtered).
(1) Note. This subclass includes certain specialized viewing devices which involve no intentional deviation of light rays such as, for example, certain underwater viewing devices. It also includes apertures, transparent closures, etc., with no significant optical element classifiable in the preceding subclasses, but some optical feature going beyond, for example, windshields in Class 296, subclasses 84.1+. This might be, for example, means to compensate for the offsetting of ray energy in passing through a transparent closure.
(2) Note. This definition does not exclude subject matter where certain rays are transmitted and certain other rays are completely blocked.
SEE OR SEARCH THIS CLASS, SUBCLASS:
227+, for movable apertured plates which control light.
480+, for binocular viewing devices.
SEE OR SEARCH CLASS
385, Optical Waveguides, appropriate subclasses for optical wave-guides which utilize total internal reflection.
