Patent ID: 8336223
Filing Date: 2012-12-25
Classification: G01B

Abstract:
1. A roundness measuring apparatus comprising: a base; a turning table that can rotate around a vertical axis, a measurement target object being placed on an upper surface of the turning table; a detector that includes a stylus and a detector main unit, the stylus being brought into contact with the measurement target object, the stylus being detachably attached to the detector main unit, the detector main unit detecting displacement of the stylus and outputting the detected stylus displacement in the form of an electric signal; a detector driving mechanism that includes a fixed column that is mounted on the base, said detector driving mechanism drives the detector so as to move the detector in a direction of the vertical axis and in a direction orthogonal to the vertical axis toward and away from the turning table; a stylus stocker that stores plural types of styli, which are prepared corresponding to shapes of measurement sites of the measurement target object, the stylus stocker being able to store the styli in such a manner that each stylus can be held on the stylus stocker and taken out of the stylus stocker; and a control unit, wherein the stylus stocker is disposed between the turntable and the column and provided outside a measurement region, which is determined on the basis of an operation range of the turning table and the detector driving mechanism, the detector driving mechanism is configured to be able to move the detector to the outside of the measurement region, when a measurement command is given, the control unit carries out measurement of roundness of the measurement target object while controlling operation of the turning table and the detector driving mechanism, and when a stylus replacement command is given, the control unit carries out stylus replacement operation between the detector main unit and the stylus stocker while controlling operation of the detector driving mechanism.