Patent ID: 8363904

Claim:
An offset amount calibrating method for a surface texture measuring machine including: a stage on which an object is mounted; a contact-type detector being provided with a stylus that is brought into contact with a surface of the object; an image probe that captures an image of the surface of the object; a relative movement mechanism that relatively moves the stage against the contact-type detector and the image probe and moves the contact-type detector and the image probe against the stage; and a controller that controls an operation of the relative movement mechanism and executes processing on measurement data obtained by the contact-type detector and image data obtained by the image probe, the method obtaining an offset amount between the contact-type detector and the image probe, the method comprising: setting on the stage a calibration chart that includes not less than two non-parallel linewidth patterns being disposed relative to a reference position of the calibration chart and each having a known width and a level difference; capturing an image of the linewidth patterns of the calibration chart by the image probe to obtain the reference position of the calibration chart; measuring at least two of the linewidth patterns of the calibration chart by the contact-type detector to obtain the reference position of the calibration chart; and calculating a difference between the reference position obtained by using the image probe and the reference position obtained by using the contact-type detector to obtain the offset amount.