Patent ID: 8240056

Claim:
An apparatus for measuring a bevel perimeter of a spectacle lens, comprising: a retractable slider; a stylus holder disposed to be vertically movable on said slider; a rod-like stylus which is held by said stylus holder and has a bevel measurement groove formed on an outer periphery thereof; a horizontal displacement measurement device which senses that said stylus has engaged with a bevel, based on determination as to whether said stylus holder has moved in a horizontal (Y-axis) direction upon the engagement, and measures a horizontal displacement of said stylus; a pressing force application device which moves said slider forward at a time of bevel measurement to press said stylus against an edge surface of the spectacle lens, thereby engaging the bevel measurement groove with the bevel; a stylus lift device which lifts said stylus holder at the time of bevel measurement; a rotation angle measurement device which measures a rotation angle of the spectacle lens with respect to said stylus; and a Z-axis-direction displacement measurement device which detects a vertical displacement of said stylus.