| 摘要 |
PURPOSE:To prevent dust from dropping in a cover by providing a projecting dustproof frame on an optical disk side at the circumferential edge of the window of the cover. CONSTITUTION:Elongated circle type windows 7A, 7B are formed at the cover 16 formed with plastic molding material confronting with an objective lens 4 and a balancer 5 at a cover plate part confronted with an optical head, and a race track shape dustproof frame 17 protruded upward by several tens or several hundreds mum is formed integrally with the cover 16 at the circumferential edge of the windows. Most of the dust dropping from an optical disk are laminated on the upper plane of the cover 16 with an area wider than that of the windows, and are moved by the vibration of an actuator, however, intrusion to the inside of the windows can be blocked by the barrier function of the dustproof frame 17. Therefore, it is possible to prevent lubricating performance from being lowered by remarkably reducing the amount of dust intruding to a lubricating plane between a fixed shaft and a bearing. |
