LENSMETER

摘要

TITLE OF THE INVENTION LENSMETER An improved lensmeter comprising a conventional optical system and a novel displaying system. The displaying system includes a novel linear encoder producing two pulse signals equivalent to the distance and direction of linear movement of the target and an circuitry for converting the two pulse signals to a dioptral number of digits with plus or minus sign and a good precision such as 0.125 or 0.06 diopter order and displaying it. The displaying system also includes two circuitries for displaying "the power of the sphere" (S) and "the power of the cylinder" (C) of an astigmatic lens respectively as a dioptral number of digits at a time, a combination of an rotary encoder and a circuitry for displaying "the direction of axis of the cylinder" (Ax) as an angular degree of digits, and further a (C) sign transposing circuit and a cylinder form transposing circuit.