| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent damage of a magnetic recording medium caused by contact sliding by making plane coarseness of one part of the periphery of a corner part of a rotary drum which delivers information signals contact-sliding with a magnetic recording medium smaller than plane coarseness of the other part. SOLUTION: A lower end corner part CA of a rotary drum 12A is assumed to an 0 point, plane unevenness in a range to a distance y1 in the direction of radius of the rotary magnetic head and to a distance in the direction of height x1 is made 0.2S or less. Then, y1 is made approximately 0.05-0.1 mm, x1 is made approximately 0.1-0.3 mm. And plane unevenness of a part contacting with a magnetic tape in the other range. Thereby, when the magnetic tape is wound on a rotary drum rotating at high speed and runs along a lead guide, it is prevented that the tape is absorbed in a gap between the rotary drum and a fixed drum 11A and damaged by contact-sliding to the lower end corner part of the rotary drum 12A, while it is prevented that the magnetic tape is stuck to the rotary drum 12A.</p> |
