Investigation of a 3D head-mounted projection display using retro-reflective screen

Ürey

2017

Appl. Opt.

We propose and demonstrate a light-efficient 3D display using a highly transparent desktop-sized augmented reality screen. The display consists of a specially designed transparent retro-reflective screen and a pair of low-power pico-projectors positioned close to the viewer's eyes to provide stereo views. The transfer screen is an optically clear sheet partially patterned with retro-reflective microspheres for high optical gain. The retro-reflective material buried in the screen reflects incident light back towards the projectors with a narrow scattering angle and facilitates the viewer to perceive a very bright content. The tabletop prototype mainly consists of an in-house fabricated large augmented reality (AR) screen (60 cm×40 cm) and a pair of laser-scanning 30 lumen pico-projectors. The display is tested for different viewing configurations, and different display parameters, such as retro-reflective coefficient, eye-box size, polarization maintainability, stereo crosstalk, and brightness, are examined. The AR prototype display provides 75% optical transparency, exceptional brightness (up to 1000 cd/m when viewed through beam splitters and 350 cd/m with bare eyes), and negligible crosstalk in 3D mode (<5% and <1% when viewed through beam splitters and polarizers, respectively) for the working distance of up to 2 m.

Section: Concept Of the Displaymentioning

confidence: 99%

Section: Brightness and Optical Gainmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Light-efficient augmented reality 3D display using highly transparent retro-reflective screen

Ürey

2017

Appl. Opt.

“…The proposed display consists of two pico-projectors and a see-through retro-reflective screen as illustrated in Figure 1. A retro-reflective surface reflects the incident light back towards source with narrow scattering and provides brightness gain 10 . The stereo content is projected on a see-through screen using the projector pair placed at distance d from the screen.…”

Section: Concept Of the Displaymentioning

confidence: 99%

“…Various augmented reality systems use headmounted or fixed projectors and distant see-through screens as transfer medium [6][7][8][9] , which include the micro-lens array 7 or resonant nano-particle 8 based see-through screens. The high brightness gain and personalized display is achieved by using retro-reflective surfaces in the surrounding instead of diffusing screens [10][11] , however to use such surfaces for augmented reality applications requires them to have optical see-through capability and brightness gain.…”

Section: Introductionmentioning

confidence: 99%

Augmented reality 3D display using head-mounted projectors and transparent retro-reflective screen

Ürey

2017

SPIE Proceedings

A 3D augmented reality display is proposed that can provide glass-free stereo parallax using a highly transparent projection screen. The proposed display is based on a transparent retro-reflective screen and a pair of laser pico projectors placed close to the viewer's head. The retro-reflective screen directs incident light towards its source with little scattering so that each of the viewer's eyes only perceives the content projected by the associated projector. Each projector displays one of the two components (left or right channel) of stereo content. The retro-reflective nature of screen provides high brightness compared to the regular diffused screens. The partially patterned retro-reflective material on clear substrate introduces optical transparency and facilitates the viewer to see the real-world scene on the other side of screen. The working principle and design of the proposed see-through 3D display are presented. A tabletop prototype consisting of an in-house fabricated 60x40cm 2 see-through retro-reflective screen and a pair of 30 lumen pico-projectors with custom 3D printed housings is demonstrated. Geometric calibration between projectors and optimal viewing conditions (eye box size, eye-to-projector distance) are discussed. The display performance is evaluated by measuring the brightness and crosstalk for each eye. The screen provides high brightness (up to 300 cd/m 2 per eye) using 30 lumens mobile projectors while maintaining the 75% screen transparency. The crosstalk between left and right views is measured as <10% at the optimum distance of 125-175 cm, which is within acceptable range.

Head Mounted Projection Display & Visual Attention

Genç

Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems

Duyan

et al. 2016

Automatic prediction of salient regions in images is a well developed topic in the field of computer vision. Yet, virtual reality omnidirectional visual content brings new challenges to this topic, due to a different representation of visual information and additional degrees of freedom available to viewers. Having a model for visual attention is important to continue research in this direction. In this paper we develop such a model for head direction trajectories. The method consists of three basic steps: First, a computed head angular speed is used to exclude the parts of a trajectory where motion is too fast to fixate viewer's attention. Second, fixation locations of different subjects are fused together, optionally preceded by a re-sampling step to conform to the equal distribution of points on a sphere. Finally, a Gaussian based filtering is performed to produce continuous fixation maps. The developed model can be used to obtain ground truth experimental data when eye tracking is not available.