傳統的光學讀取頭需要多個物鏡和多個光電感測器和多條光軸才能將Blu-ray、DVD的讀取裝置結合，其成本容易偏高，結構也較為複雜，且在製程及校對光軸時較為費時費力，整個光路也較為龐大。本論文提出一個單光電偵測器之複合式光學讀寫頭的設計，在光學讀寫頭的去光路用了一些稜鏡組和鍍膜來達成分光的效果，在回光路加上了全像型光學元件(HOE)，使二種波長的光能夠同時共用同一個物鏡、準直鏡、波長選擇鏡，大幅的減少了成本，結構也簡單許多，製程容易，因為所需光學元件較少，整個光路設計也比傳統型縮小許多，對於日後複合式讀取頭的微型化相信會有明顯的幫助。 The traditional design of a combination of Blu-ray and DVD was needed to use a number of objective lens, photo-electricity sensors and optical axes for a combo optical pick-up head, the disadvantage of this design is that higher cost occurred, a complicated construction, a time-consuming process and optical axis checking, and the entire optical path is large. This research proposes a design of a combo-optical pick-up head with a single photo-electricity sensor, its uses prisms and coatings to divide the light on the forward path, and uses the holographic optical element (HOE) on the returning path. For this design, it presents that we can use an objective lens, a collimating lens and a wavelength selector for two different wavelength light sources of Blur-ray and DVD. Because it uses less elements of an optical pick-up head, it can help cost down, processes simplified, and easy to produce. With such a design, the whole optical path will be shorter than traditional ones, it will be significant help for a miniaturized combo-optical pick-up head in the future.
