臺灣博碩士論文加值系統

本文乃針對一般行動電話揚聲器聲音品質不佳或過於尖銳之缺點，運用有限元素分析軟體加以模擬分析，並藉此以獲得最佳的幾何尺寸參數來提升行動電話揚聲器的性能表現。揚聲器的整體作動特性是耦合了電、磁以及其外觀的機械結構。在理論分析方面，以圓形板的振動理論來分析振動板的共振頻率及模態，並以電學理論為基礎計算出音圈所產生的驅動力。在有限元素軟體進行模擬分析之後，瞭解振動板花紋數目對振動板強度的影響，以及揚聲器機構外觀對磁通量的影響。這些分析結果，對於日後研發新的揚聲器可提供參考的數據，並有助於改進現有揚聲器的性能。

The aim of the present study is to overcome drawbacks and to improve sound quality of speakers that are widely used in cellular phones nowadays. By adopting the finite element method commercial code ANSYS, the simulation and analysis of the cellular phone speaker, coupling the electricity, magnet and its outer mechanical structure, are performed. Through the finite element code, optimal parameters of geometry dimensions to enhance the performance of cellular phones are obtained. In addition, the natural frequency and mode shape of diaphragm as well as the force excited by the voice coil on the diaphragm are presented. The analysis results indicate that the number of patterns of diaphragm affects its strength. Moreover, it is also found that mechanical structure has effect on the magnetic flux. The results obtained herein can improve the performance of present cellular phones and equally provide valuable data for developing the next generation cellular phones.

第一章 緒論~1
1-1 背景~1
1-2 研究動機~2
1-3 文獻回顧~4
1-4 內容簡介~5
第二章 揚聲器應用理論~7
2-1 圓形振動板理論~7
2-2 聲場統御方程式~14
2-3 基本磁學理論~22
第三章 揚聲器模擬與分析~29
3-1 分析軟體簡介~29
3-2 小型揚聲器結構簡介~30
3-3 振動板模擬分析~33
3-4 磁氣迴路分析~48
3-5 結果與討論~57


第四章 揚聲器設計與分析~59
4-1 量測儀器與標準~59
4-2 樣品尺寸與分析~62
4-3 結果與討論~69
第五章 結論與展望~72
5-1 結論~72
5-2 未來研究方向~74
參考文獻~76

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