| 摘要 |
<p>PURPOSE:To reduce a power which is used to drive a video tape, to prevent the tape from being damaged and to make the linearity of a signal good by a method wherein a groove for air-film formation use is formed in a disk. CONSTITUTION:A groove 9 for air-film formation use is formed in a disk 3A. Thereby, when the disk 3A is turned, a dynamic pressure due to flows 10 of the inhaled air are generated in the groove 9 as shown by a distribution 11. In addition, when the disk 3A is turned, the air is pulled into parts between drums 1, 2 and a video tape by means of the groove 9; gaps (air films) of the air are generated between the video tape, the drums 1, 2 and the disk 3A. Thereby, since the drums 1, 2 do not come into close contact with the video tape, it is possible to reduce the power which is used to drive the video tape. Since the contact area of the disk 3A with the video tape is small, the video tape does not vibrate and its linearity becomes good.</p> |
