(under subclass 257) Subject matter wherein the light source consists of a gas or vapor containing ionized or partially ionized molecules or atoms which, in changing their ionization states from nonionized to ionized or vice versa or from one ionization level to another, emit visible radiant energy.
(1) Note. The subject matter of this subclass and the subclasses indented hereunder includes, for example, gas or vapor discharge-type light sources and "glow" tubes which are virtually point sources of light.
SEE OR SEARCH THIS CLASS, SUBCLASS:
216, for an ionized gas or vapor light source which is or includes a virtually curved line segment.
217+, for an ionized gas or vapor light source which is or includes a virtually straight line segment.
260, for a fluorescent light source which emits visible light in response to incident invisible radiation emitted from an ionized gas or vapor discharge.
