(under subclass 642) Subject matter wherein the lens has at least one component or one element which uses a transparent liquid or gas as its refractive material.
(1) Note. The lens components or elements under this definition may comprise either a mass of fluid supported in a capillary channel which has its refracting surfaces freestanding and formed by surface tension or a mass of fluid which is enclosed in and shaped by a transparent shell or casing. In the latter form of component or element, the fluid may be either a liquid or a gas, and in addition to refraction, may perform other functions (e.g., cooling).
SEE OR SEARCH THIS CLASS, SUBCLASS:
886, for fluid filters.
894, for gas-filled telescope or microscope barrels.
SEE OR SEARCH CLASS
351, Optics: Eye Examining, Vision Testing and Correcting,
159, for spectacle lenses having a fluid-refractive element.
