(under the class definition) Subject matter including optical structure to indicate the deviations in light rays which are reflected from or transmitted through a material, which deviations are in turn due to deviations in the flatness of the material.
(1) Note. The flatness deviation may result from surface or thickness irregularities in the material, or bends or wrinkles in otherwise flat sheet material.
SEE OR SEARCH THIS CLASS, SUBCLASS:
124+, for lens testing or reflective image former testing.
237.1+, for inspection for flaws or interperfection in material generally.
359+, for interferometer type flatness testers.
432+, for optical transmission testing generally.
445+, for optical reflection testing generally. SEE OR SEARCH CLASS