PURPOSE: To provide a frame shape measuring instrument which interrupts measurement by fixing a sensor part by judging that possibility to deviate the sensor part from a lens frame occurs when radius vector information (ρn, θn) exceeds a fixed value.
CONSTITUTION: This instrument is the frame shape measuring instrument provided with a frame holding means which holds a spectacles frame, the sensor part 312 being abutted with a rotating sensor arm and the V-groove of the lens frame movable along the sensor arm, a measuring means which measures the shape of the lens frame from the angle of rotation of the sensor arm and the amount of travel of the sensor part 312 as the radius vector information (ρn, θn) (n=1, 2, 3,..., N), and a block means which compares the change quantity of ρn with a reference range value which shows the range of the change quantity decided in advance and blocks the rotation of the sensor arm when the change quantity of ρn is set at a value other than the reference range value.
ISOKAWA NOBUHIRO
SUZUKI YASUO
HATANO YOSHIYUKI
OGUSHI HIROAKI
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