| 摘要 |
PURPOSE:To check the presence of a relative position shift and its size of a reference face due to generation of interference fringe by providing a transparent check member having the surface with a flatness with high close contact to at least the reference plane of a magnetic head block made of a couple of block halves. CONSTITUTION:In mounting a magnetic head block 6 to a joint positioning device, if minute dust 8 exists between the reference plane 63 of the magnetic head block 6 and a position deciding plane 11 of a main check piece 11, a relative position shift (d) is produced to the reference faces 63, 64 of both block halves 60, 61 and track slots 62 are not coincident. The main check piece 1 is formed with a transparent quartz glass and a position detecting plane 11 has a high flatness, then a difference of the optical distance is produced to lights reflected on the upper face and the lower face of the thin film air gap between the main check piece and the magnetic head block due to the said position shift and the interference fringe 7 is observed while observing the main check piece 1 from the direction of the arrow (a) in Fig. On the other hand, when no position shift exists to the reference plane of both the block halves and the reference plane is contacted closely to the position deciding plane, no interference fringe appears. |
