Artifact, arm, method and apparatus for measuring position of the read/write arms of computer memory disks during servo-track writing.

摘要

An artifact (2) is used in the positioning of the read/write arm (4) during servo-writing (32) of a computer memory disk. A method for positioning the arm (4) using the artifact (2), and an apparatus incorporating the method is also included. The artifact (2), when applied to a moveable read/write arm 84), which traverses the surface (6) of a computer memory disk can be read without the presence of the housing, or through a permeable window in the housing of the disk, and which is read by an external laser beam (14; 84, 85) and thence processed by interference laser metrology techniques to produce an electrical signal which provides a representation of the displacement of the arm (4) from the center of the disk. Winchester drives provided with one or more optical windows to view the artifact-containing arm are especially adaptable to use of this artifact (2), apparatus, and method of this invention. <IMAGE>