| 摘要 |
PURPOSE:To improve the accuracy of the head height and to miniaturize the device by providing the thrust bearing fitting surface in the same direction as the fixed drum fitting reference surface. CONSTITUTION:To record and reproduce to the prescribed position of a magnetic tape 17 with a high accuracy, it depends upon the accuracy to position a height (h) from an edge surface 17' of the tape 17 to a head. To position the (h), a height H3 from a magnetic head 3 up to the edge surface of a shaft 5 is already set to the constant value, and therefore, a height H1 from a fixed drum fitting reference surface 11 up to a lead 18 and a height H4 up to a thrust bearing fitting surface 19 are determined. Namely, h=H2-H1, H2=H3+H4 and h=H3+H4-H1 is obtained. Here, H1 is spirally set to a fixed drum 6 on the basis of the reference surface 11. For such a reason, the accuracy of (h) depends upon the accuracy of H4. From such a point of a view, the thrust bearing fitting surface 19 is provided in the same direction as the reference surface 11, and thereby, the recording and reproducing can be executed with a high accuracy. |
