A Structure of Optical See-Through Head Mounted Display

In the paper, we suggest the optical see-through head mounted display (OST-HMD) for self-contained augmented reality (AR) environment. In the OST-HMD system, several types of optical architectures such as microprojector, spatial light modulator (SLM), diffraction optical elements (DOE), polarized beam splitter (PBS) are used. For comfortable use, HMDs should have small size, light weight, better mobility, no screen door effect, and minimum burden on skin. Technologically HMDs should provide higher resolution, less latency, wider field of view (FOV), wider color gamut, sufficient refresh rate, reliable eye tracking method and higher pixel per degree (PPD). Existing HMDs use optical combiners in front of projection optics, which reduce the visibility of the real-world and thus harm the sense of realistic interaction with the surronding world. Instead of the front optical combiner, we used transparent projection optics, PBS, and SLM for better view of the environment through the optical components and they enhanced the sense of reality in interaction with objects in the environment. We also used the pinhole array structure to increase FOV and resolution. To interact with the surronding world in AR, we adopted the 6 degrees of freedom (6DOF) microelectromechanical system inertial measurement unit (MEMS IMU) in the center of the HMD and created a depth map of real objects using time of flight (TOF) method. Figure 1. shows the concept of OST-HMD (left of Figure. 1) and the optical structure in the paper. (right of Figure. 1). We suggested the OST-HMD optical structure with transparent projection optics and MEMS IMU, which increased real-world visibility and the sense of presense. We will further improve the performance and simplify the structure by using ray tracing and image processing methods.1

높은 몰입감 제공을 위한 조도 전환형 혼합현실 전용 강의실 설계

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Concept of spatial front sound and optically invisible antenna on display liquid crystal cellular devices

Presently, Liquid Crystal Displays (LCDs) are the dominant technology over the display market. However, a long with the r apid development in OLED technology , the LCD industry is facing through challenges and requiring new applications based on its intrastructure This paper proposes a novel c oncept of an LCD panel combined with spatial front speakers and optically invisible anten na s While conventional cellular devices have a Bottom Facing S peaker , it adopts a dual channel front facing speaker. Existing front sound devices such as Crystal Sound OLED(CSO) utilize the panel as a flat diaphragm and it is because the OLED panel i s thinner and more durable than LCD s . Different from the earlier approaches , we suggest a different front sound technology , which chooses Touch Screen Panel(TSP) as a diaph ragm in front of the d isplay panel. Fig. 1.(a) depicts a direct driving front sound generation structure. The exciter at Au dio Layer(AL) produces a spatial sound by vibrating TS P and our two exciters delivers the vibration s to the top and bottom plates. Those d istributed sounds built in dual channel provides volumetric stereo sound. In th e case of an optically invisible antenna, a liquid crystal ( layer is used as a phase shifter. Fig. 1.(b) shows a single anten n a element unit . The i nserted microstrip antenna radiates an ele c tromagnetic wave to upward direction and birefringence properti es of LC modify the wave front . In order to avoid the effect that the electrode blocks the radiation of the EM wave, we ch ose the In Pla ne Switching(IPS) configuration whose pixel consists of 4 sub pixels , such as red, gree n, blue and antenna element. The aligned several pixels constitute a phased array antenna on the LCD panel. We are optimizing the sound and electromagnetic wave using Finite Element Method (FEM) simulation package, COMSOL MULTIPHYSICS. It enables us to estimate and compare the sound and antenna quality of the cellular device. Display specifications such as transmittance and color gamut are calculated by TECHWIZ LCD, three dimensional LCD simulation software. In conclusion, this paper presents a concept of a new type cellular device combined with the Sound on Display (SoD) and Antenna on Display (AoD) technologies. The proposed cellular device, with functions of display, speaker and antenna, can have excellent bezel-less properties, and various modules in the present cellular display can be also included.1

Concept and Numerical Modeling for virtual acceleration sense on vestibular organ using focused ultrasound

Presently, Liquid Crystal Displays (LCDs) are the dominant technology over the display market. However, a long with the r apid development in OLED technology , the LCD industry is facing through challenges and requiring new applications based on its intrastructure This paper proposes a novel c oncept of an LCD panel combined with spatial front speakers and optically invisible anten na s While conventional cellular devices have a Bottom Facing S peaker , it adopts a dual channel front facing speaker. Existing front sound devices such as Crystal Sound OLED(CSO) utilize the panel as a flat diaphragm and it is because the OLED panel i s thinner and more durable than LCD s . Different from the earlier approaches , we suggest a different front sound technology , which chooses Touch Screen Panel(TSP) as a diaph ragm in front of the d isplay panel. Fig. 1.(a) depicts a direct driving front sound generation structure. The exciter at Au dio Layer(AL) produces a spatial sound by vibrating TS P and our two exciters delivers the vibration s to the top and bottom plates. Those d istributed sounds built in dual channel provides volumetric stereo sound. In th e case of an optically invisible antenna, a liquid crystal ( layer is used as a phase shifter. Fig. 1.(b) shows a single anten n a element unit . The i nserted microstrip antenna radiates an ele c tromagnetic wave to upward direction and birefringence properti es of LC modify the wave front . In order to avoid the effect that the electrode blocks the radiation of the EM wave, we ch ose the In Pla ne Switching(IPS) configuration whose pixel consists of 4 sub pixels , such as red, gree n, blue and antenna element. The aligned several pixels constitute a phased array antenna on the LCD panel. We are optimizing the sound and electromagnetic wave using Finite Element Method (FEM) simulation package, COMSOL MULTIPHYSICS. It enables us to estimate and compare the sound and antenna quality of the cellular device. Display specifications such as transmittance and color gamut are calculated by TECHWIZ LCD, three dimensional LCD simulation software. In conclusion, this paper presents a concept of a new type cellular device combined with the Sound on Display (SoD) and Antenna on Display (AoD) technologies. The proposed cellular device, with functions of display, speaker and antenna, can have excellent bezel-less properties, and various modules in the present cellular display can be also included.1

A structure of optical see-through head mounted display

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Impact of Immersive Virtual Reality Content Using 360-degree Videos in Undergraduate Education

This study investigated the impact of immersive virtual reality (VR) content, using 360-degree videos, in undergraduate education. To improve the delivery and reality of 360-degree VR content, we filmed the video in the third person so that the viewers could feel like they were in the environment where the lecture was conducted. To verify the educational effects, 33 university students participated in our experiment. We conducted pre-test learning, using 360-degree videos, and post-test learning via conventional 2D videos for statistical analysis. A paired t-test was used to compare the means of the pre-test and the post-test. In addition, learning via 360-degree videos was assessed for its effectiveness through questionnaires consisting of five measurement elementsengagement, immersion, motivation, cognitive benefits, and perceived learning effectivenessand comparing them to the existing 2D video method, based on e-learning. From the results, we confirmed that the teaching material delivered through 360-degree VR content allows students to be more focused, immersed, and interested than 2D learning modes. Furthermore, the high scores of cognitive and perceived learning elements imply that VR-based 360-degree educational content can encourage more active participation than traditional lectures, and can improve the ability to analyze and organize study lessons. IEEE11Nsciessciscopu

Comparison of Figure-of-Merit Efficiency in Liquid Crystal Phase Shifter Operating Modes: Electrically Controlled Birefringence vs. In-Plane Switching

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Self-Controlled Electroactive Tunable Liquid Lens for Stabilized Focal Length Change

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Simulation Analysis of LC-Based Array Antenna Operation and Its Radiation Pattern

An liquid crystal(LC)-based array antenna is of increasing interest in academy and industry because of many advantages over conventional antennas in various aspects. While conventionol antennas show fixed radiation pattern for a given frequency, the array antenna induces various radiation patterns by controling amplitude and phase of individual antenna elements. In an LC-based array antenna, LCs manipulate the phase of the RF signal while the amplitude can be set by signal input circuits. If the RF signal penetrates through the LC layer as the incident light does inside the traditional liquid crystal displays (LCDs), the thickness becomes beyond acceptable limit of reasonable material cost. Therefore, we made the RF signal propagate on the substrate in our LC antenna simulation so that the thickness of the LC layer and LC response time decreases. The LC array antenna consists of N by N microstrip unit antennas, tunable delay lines on the substrate, RF feeding and biasing networks. The RF phase shift is determined by the length of the delay lines and the effective permittivity of LCs around the delay lines. To obtain an appropriate phase shift, the vector components of LC directors around the delay lines are extracted by using a commercial LCD simulation package. And an effective permittivity profile is calculated by using the three dimensional LC director alignment. From the effective permittivity profile, we can create a waveguide model in RF signal simulation programs, and the phase shift can be estimated, which is used for the radiation pattern calculation. Figure 1. (a) shows the schematic design of the LC-based array antenna with rectangular microstrip patches and Figure 1. (b) shows the radiation pattern of the array antenna. The suggested simulation process connecting the LC simulation program and the RF simulation tools can be a good basis for analysing and designing the LC-based array antennas.1

Improved stability of electroactive elastomer tunable lenses

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