單向投影成像透視膜片應用於擴增實境之研究

Abstract

本實驗室過去已成功開發透視膜片，其散射微結構由微透鏡構成，短焦投影機投射影像到透視膜片，觀察者可同時觀察到投影機影像與膜片後景物，但正對投影機投射光源側有強眩光現象，若是在人數較多的場合使用該膜片，強眩光將會對其他非觀察者造成視覺上的不適。 因此本論文提出一個單向投影成像透視膜片的設計方法，其膜片主要架構由微稜鏡結構、鍍銀面與粗糙面構成，膜片左側結構是稜鏡與鍍銀面，目的是收集光線且阻隔光線到左側觀察者的眼睛位置達到單向顯示，膜片右側是粗糙面，將左側收集到的光線成像在粗糙面上散射到右側觀察者的眼睛位置。設計完成後利用Light Tools光學模擬軟體驗證，其平行光穿透率達到78%，兩側觀察者的觀察位置輝度比1：22。此單向投影成像透視膜片可做為投射式擴增實境系統的虛擬資訊顯示媒介，搭配光學觸控偵測系統，達成視覺與觸覺上的擴增實境應用。

Micro optics and display system laboratory have developed the transparent screen successfully. The scattering microstructure was constructed by the lens, and the short focal projector projected the image on the transparent screen. Users can observe the projection screen and the object behind the transparent screen, but there is a bright spot resulted from the projector which called glare phenomenon. If the transparent screen is used in a place where is full of people, the glare phenomenon causes the nonusers to get an uncomfortable sense of vision. This thesis presents a design process of unidirectional transparent screen. The micro structure film is made of the prism, the slivered surface, and the rough surface. Left part of the screen is made of the prism and the silvered surface. The purpose of the silver is to block the rays toward the left user and to reflect light to the right user. This structure makes a unidirectional observing system. Right part of the screen is a rough surface which can be imaged on itself due to the rays from left part, then the right user’s eye can receive the scattered light from the rough surface. The performance of design was proved by Light Tools optical simulation software. It’s parallel transmittance is 78%, and the luminance ratio of each user’s eyes is 1:22. The unidirectional transparent screen could be a display of virtual information applied on projection-based augmented reality system. Furthermore, the system could be combined with touch panel then achieves visual perception and tactile perception of augmented reality.