2D/3D-Display Auto-Adjustment Switch System

Recently, 2-D/3-D switchable displays have become the mainstream in 3-D display technologies, and people can now watch 3-D movies with a naked 2-D/3-D switchable display at home. However, some studies have indicated that people might encounter visual fatigue after enjoying a 3-D film in the theater. Although 2-D/3-D switchable technologies have been widely developed, 3-D display technologies are still lacking in ergonomic and human-care factors such as reducing visual fatigue. This study proposes a novel 2-D/3-D display autoadjustment switch system to provide biofeedback functions to reduce users' visual fatigue. In addition, the relationship between the blink rate and the visual fatigue state while watching 3-D films was investigated and quantified. In this study, liquid crystal barrier technology was used to develop a 2-D/3-D switchable display, and a wearable EOG acquisition device was also designed to monitor electro-oculography signals to estimate the blink rate. Here, the 2-D/3-D display autoadjustment criterion of the proposed system was designed according to the change in the visual fatigue state as estimated from the blink rate. Finally, the experimental results show that the proposed system could effectively reduce users' visual fatigue while watching 3-D films.

I. Introduction

2D/3D switchable display technology is a mainstream 3D display technology. People can currently watch videos with a naked 2D/3D switchable display at home. Several 2D/3D switchable display techniques have been proposed in previous studies to try and satisfy the market requirements. In 2002, A. Jacobs proposed a 3D display that could switch electrically between 2D and 3D modes [1]. Here, a switch lens made by a lens correction profile (LCP) lens and a switch cell panel could be placed in front of the base panel to provide the functionality of a 2D/3D switchable display. Although the above switch lens was compatible with the liquid crystal display (LCD) process, its structure was relatively complicated. In 2008, H.K. Hong et al. used an electrically-driven liquid crystal (LC) lens for 2D/3D switchable displays to reduce the structural complexity [2]. However, the cell gap was large and it still required a complicated electrode structure. In 2014, H. Ren et al. applied twisted nematic liquid crystal (TN-LC) cell, pattern indium tin oxide (ITO), and the concept of a parallax barrier for the LC barrier technology to reduce the requirements of the electrode devices [3]. The 2D display mode and 3D display mode could be easily switched using the TN-LC technique by controlling the voltage of the TN-LC without the complicated electrode structure. In 2009, C.W. Chen et al. proposed a high-resistance liquid crystal (HRLC) lens. The advantages of HRLC were the smooth electric-potential distribution within the LC layer under driving status and the fast switching time [4].