光碟機動態之研究

Abstract

本文分為兩部分。第一部分先探討傳統DVD光碟機。首先由電腦輔助設計軟體Pro/E繪出光碟機之機構體幾何模型，其次運用有限元素分析軟體ANSYS，將DVD光碟機機構體的幾何形狀網格化，分別求出光碟機構體重要零件的自然頻率及模態振形，並求出各零件組合後，整個系統的自然頻率與振形。然後探討機構體塗佈阻尼材料後機構體的抗振能力增加程度。第二部份為先進光碟機之光學讀取頭研究。先進光碟機運用近場光學原理讀寫資料，因此讀取頭的飛行高度必須被嚴格的控制，光碟片旋轉所擾起的氣流與讀取頭之間形成空氣軸承，空氣軸承在讀取頭表面所形成的壓力分佈為讀取頭昇力的主要來源。本文探討改變空氣軸承入口出口高度比、不同讀取頭長度及不同的讀取頭導角，對空氣軸承所產生昇力的影響。最後執行包含讀取頭和懸吊臂結構與流場的耦合分析，觀察流力造成的結構變形位移。

This study includes two parts. The first part investigates vibration of a DVD-ROM mechanism. The geometry files of the DVD-ROM are created by a computer-aided design software, Pro/E. Finite element analysis is carried out by ANSYS to obtain natural frequencies and vibration modes of each component in the DVD-ROM. In addition, this study examines vibration reduction performance of the DVD-ROM mechanism, on which surface coating of a damping material is applied. The second part investigates the disk-head interface of an advanced optical data storage system. The system uses near-field optical technology to read/write data so that the flying head must be positioned with greater precision. The pressure, caused by the air-bearing, is integrated over flying head surface, yields a lifting force to the flying head. Finite element method is employed to examine fluid lifting force distribution when changing the inlet-outlet height ratio, head length, and the chamfer angle. Finally, flow field analysis is coupled to structure analysis dealing with optical head and load arm, so as to observe structure deformation.