Patent ID: 7318285

Claim:
A surface profile measuring instrument, comprising: a measuring section including a stylus having a contact portion to contact a workpiece surface at a tip end and a measuring force detecting unit which detects a measuring force when the contact portion abuts on the workpiece surface; a moving unit which moves the measuring section relative to the workpiece surface; and a drive control unit which controls the moving unit based on the magnitude of the measuring force detected by the measuring force detecting unit, the contact portion being brought into contact with the workpiece surface to measure the workpiece surface, wherein the drive control unit includes: a scanning-measurement control section which controls the moving unit such that the moving unit conducts a scanning-measurement in which the measuring force is a preset designated scanning measuring force and the contact portion is moved for scanning along the workpiece surface; and a touching-measurement control section which controls the moving unit such that the moving unit repeatedly conducts touching-measurements on the workpiece surface, in the touching measurements the contact portion being brought into and then out of contact with the workpiece surface, the contact portion contacting the workpiece surface at a touch detecting measuring force set smaller than the designated scanning measuring force, the measuring force detecting unit has a predetermined measuring force detecting direction, the measuring force detecting unit detecting the measuring force acting in the direction, when the contact portion contacts the workpiece surface in a direction along the measuring force detecting direction, the scanning-measurement control section conducts the scanning-measurement, and when the contact portion contacts the workpiece surface in a direction deviated from the measuring force detecting direction, the touching-measurement control section conducts the touching-measurement.