(under subclass 668) Subject matter wherein the components that produce the unequal magnifications in the lens are symmetrically refracting prisms disposed with their refracting surfaces transversely of the optical axis of the lens.
(1) Note. The prism components may be mounted either in a fixed relation to the optical axis of the lens or each of these components may be mounted to rotate about an axis parallel to its refracting edge, in which latter case the difference between the magnifications in the two planes is variable.
(2) Note. See subclass 831 for the definition of a prism.
