head unit短语¹⁸⁰⁰⁹⁸⁺¹ 基本例句 🌏头部；汽车音响主机；汽车音响本体 Studying the theory of optical pickup head unitOPU and how to pickup the signal on the disk. Based on these theories, it analyse the structure of the focusing and tracking device. 研究光学拾取头的基本原理和光盘信号拾取原理，简要分析了实际的光学头聚焦伺服和循迹伺服的机械结构。 cnki