將曲面型透鏡陣列應用在視網膜投影之研究

Retina Projection using curved lens arrays

10.6342/NTU201700567

嚴浩仁

透鏡陣列 ； 複眼 ； 視網膜投影 ； 頭戴式顯示器 ； 視網膜 ； lens array ； compound eye ； retina projection ； head-mounted display ； retina

臺灣大學光電工程學研究所學位論文

2017年

碩士

蘇國棟

英文

隨著科技的進步，電腦的硬體設備更加進化，使需要高規格電腦配備的頭戴式顯示器的品質逐漸提升，在需求方面，現代科技產品在設計上越來越注重輕薄的特性以及方便攜帶的體積。在體積部份，藉由國內各大科技廠的辛苦研究，光學系統以外的電路設計所需之體積正逐漸減小，然而光學系統的部分仍遲遲無法有大幅度的縮小，厚度大約維持40毫米到60毫米之間，除此之外，頭戴式顯示器為了提供人眼較廣的視角，也會使光學系統體積增加，但體積增加並不是消費者所樂見，固在兩者之間做取捨後，現在市售產品所提供的視場角度大約120度。在隨著體積越做越薄、輕巧及高解析度的趨勢，光學系統設計想法和製作難度也不斷提升。因此，如何在有限的空間中，提供人眼更大的視角與不錯的成像品質，也成為現在的光學公司和硬體廠商的主要研究方向之一。 在本篇論文中，我們提出了一種多通道的光學系統。這是一種具有更廣的視場角度與較小的體積且輕薄的成像投影系統，厚度不超過30毫米，寬度不超過眼鏡單邊寬度，且能提供150度的視場角度，超越現有規格也符合市場的需求，在之後的內文中，會對這個結構做詳細的描述。 我們利用光學設計軟體 ZEMAX，建立我們所有的光學元件。我們設計的光學系統是結合多通道光學系統與昆蟲複眼架構組合而成的視網膜投影系統，透鏡與透鏡之間以六角形透鏡陣列的方式相鄰，組成中間一個外圍六個共七個的光學通道，每個單一通道中設置兩片非球面鏡，加上透鏡間以曲面的排列方式來模擬昆蟲複眼的結構。 藉由特別設計的光圈，使面板上不同部分圖像所發出的光會分別進入不同的通道，通過透鏡後打入人眼瞳孔，並在視網膜上由七個通道所提供的光線接合，形成一個完美接合的影像；除此之外，因為透鏡表面中心以及邊緣的折光程度不同，我們設計光線只通過透鏡的特定部分來使光偏折，如此一來為了達到大視角所需之光學系統體積就可以被縮小。 由於製程技術之進步，相信在未來有機會在頭戴式顯示器上加入此光學結構，使人們有更棒的體驗。在本篇的最後，我們有做一些簡單的結構實驗與討論。

In this thesis, we propose a multi-channel imaging system which combines the principles of optical cluster eye and an insect’s compound eye. The system consists of two curved lens arrays. Both of them have the same curvature and the radiuses of the lenses in the arrays are optimized to focus rays on the retina. In order to achieve high fill factor, we design a shape like a honeycomb array. The optical axes of different channels are tilted to each other in order to reduce the optical system volume and transmit a wide field of view. Each channel of multiple channel optical system transfers only a part of the field of view. Each partial image passes through each channel and stitches together on the retina to reconstruct a complete image. In order to simulate the image stitch result, we also build an eye model in the optical design software ZEMAX. In our design, the thickness of our optical system is less than 30 mm. The panel size is designed to be 4 inch (per eye) which is the scale of the eyeglass. The system can provide large field of view about 150 degree which is much wider than the commercial products. By using a 3D printer, we can make a mold of lens to achieve our design.

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