A Wearable Head-mounted Projection Display

Conventional head-mounted projection displays (HMPDs) contain of a pair of miniature projection lenses, beamsplitters, and miniature displays mounted on the helmet, as well as a retro-reflective screen placed strategically in the environment. We have extened the HMPD technology integrating the screen into a fully mobile embodiment. Some initial efforts of demonstrating this technology has been captured followed by an investigation of the diffraction effects versus image degradation caused by integrating the retro-reflective screen within the HMPD. The key contribution of this research is the conception and development of a mobileHMPD (M-HMPD). We have included an extensive analysis of macro- and microscopic properties that encompass the retro-reflective screen. Furthermore, an evaluation of the overall performance of the optics will be assessed in both object space for the optical designer and visual space for the possible users of this technology. This research effort will also be focused on conceiving a mobile M-HMPD aimed for dual indoor/outdoor applications. The M-HMPD shares the known advantage such as ultralightweight optics (i.e. 8g per eye), unperceptible distortion (i.e. ≤ 2.5%), and lightweight headset (i.e. ≤ 2.5 lbs) compared with eyepiece type head-mounted displays (HMDs) of equal eye relief and field of view. In addition, the M-HMPD also presents an advantage over the preexisting HMPD in that it does not require a retro-reflective screen placed strategically in the environment. This newly developed M-HMPD has the ability to project clear images at three different locations within near- or far-field observation depths without loss of image quality. This particular M-HMPD embodiment was targeted to mixed reality, augmented reality, and wearable display applications

Overview of open source augmented reality toolkit

Augmented reality or also known as AR is not a new technology. The technology has existed for almost 40 years ago after Ivan Sutherland introduced the first virtual reality (VR) application. At that time, works and research were mainly concerned to establish the hardware aspects of the technology. The head-mounted display (HMD) or some might called head-worn display is the result of augmented reality research and also one of the fundamental equipment for accessing the technology. As time goes by, the augmented reality technology has begin to mature to a point where the hardware cost and capabilities have collided to deliver a more feasible AR thus enable the rapid development of AR applications in many fields including education. To create a non-commercial AR application specifically for education, the ARToolkit can be taken into consideration. ARToolkit is the product of AR community and it is registered under the GNU General Public License. The user is provided with basic source code that lets the user easily develop Augmented Reality applications. Despite the fact that AR is not a new technology, people may unaware or unfamiliar with its existence. Therefore this paper is intended to (1) give an overview of augmented reality; and provides (2) solution to the technical problems that one’s will face in setting up open-source augmented reality toolkit

Field Projection Device of Atomic Bomb Dome by Augmented Reality

We developed a projection device with Head Mounted Display through which visitors to Atomic Bomb Dome can see the 3D image of what the dome used to be before the dropping of the bomb. This wearable device, based on the technology of augmented reality (AR), enables wearers to have a clear understanding of the effect of the bomb by showing the difference before and after the catastrophe, because the 3D image of Hiroshima prefectural products museum is projected exactly where Atomic Bomb Dome is seen in the wearer's field of view. This development was carried out in the wake of our field interview for foreign visitors. Many hoped that they would learn about Hiroshima prefectural products museum and some suggested that we build its life-size replica just beside the dome. Since building it physically is out of the question, we struck on the idea of building it virtually utilizing AR technology. Technically, our device is composed of a Head Mounted Display available on the market and an original application we programed. The difficulty of the development lay in the way of programing and installing the original software because its built-in installer could install only a few official applications for the hardware and therefore it might not execute any other original applications. Even if it could, controlling built-in hardware devices, a camera in this particular case, was not guaranteed. Through trial and error we found a way to install our software and execute it. Controlling the camera was also successful

Empirical Comparisons of Virtual Environment Displays

There are many different visual display devices used in virtual environment (VE) systems. These displays vary along many dimensions, such as resolution, field of view, level of immersion, quality of stereo, and so on. In general, no guidelines exist to choose an appropriate display for a particular VE application. Our goal in this work is to develop such guidelines on the basis of empirical results. We present two initial experiments comparing head-mounted displays with a workbench display and a foursided spatially immersive display. The results indicate that the physical characteristics of the displays, users' prior experiences, and even the order in which the displays are presented can have significant effects on performance

Spatial calibration of an optical see-through head-mounted display

We present here a method for calibrating an optical see-through Head Mounted Display (HMD) using techniques usually applied to camera calibration (photogrammetry). Using a camera placed inside the HMD to take pictures simultaneously of a tracked object and features in the HMD display, we could exploit established camera calibration techniques to recover both the intrinsic and extrinsic properties of the~HMD (width, height, focal length, optic centre and principal ray of the display). Our method gives low re-projection errors and, unlike existing methods, involves no time-consuming and error-prone human measurements, nor any prior estimates about the HMD geometry