ENVIRONMENTAL ADAPTATION FOR HEAD MOUNTED DISPLAYS

When virtual reality (VR) users initially don their headset, the initial scene displayed can be much brighter than the ambient light the users are adapted to. This can cause some levels of eye discomfort. Gradual transitions from the real world to the virtual environment (VE), and smooth transitions from one VE to another can increase immersivity of the virtual experience

Coupling thermal subsystems on head-mounted displays

A multi-body augmented or virtual reality device is a head-mounted display whose constituent units can be flipped up, e.g., from over the eyes to over the forehead. In a multi-body AR/VR device, thermal problems associated with high processing power are exacerbated by the need to cool down each constituent unit. This disclosure describes techniques that achieve efficient thermal regulation in a multi-body wearable device by establishing a conductive or convective thermal path between the constituent units of the device. The techniques enable a flexible and ergonomic industrial design, and reduce duplicated componentry, weight and cost

An automated calibration method for non-see-through head mounted displays

Accurate calibration of a head mounted display (HMD) is essential both for research on the visual system and for realistic interaction with virtual objects. Yet, existing calibration methods are time consuming and depend on human judgements, making them error prone, and are often limited to optical see-through HMDs. Building on our existing approach to HMD calibration Gilson et al. (2008), we show here how it is possible to calibrate a non-see-through HMD. A camera is placed inside a HMD displaying an image of a regular grid, which is captured by the camera. The HMD is then removed and the camera, which remains fixed in position, is used to capture images of a tracked calibration object in multiple positions. The centroids of the markers on the calibration object are recovered and their locations re-expressed in relation to the HMD grid. This allows established camera calibration techniques to be used to recover estimates of the HMD display's intrinsic parameters (width, height, focal length) and extrinsic parameters (optic centre and orientation of the principal ray). We calibrated a HMD in this manner and report the magnitude of the errors between real image features and reprojected features. Our calibration method produces low reprojection errors without the need for error-prone human judgements

Discomfort luminance level of head-mounted displays depending on the adapting luminance

The Images in an immersive head-mounted display (HMD) for virtual reality provide the sole source for visual adaptation. Thus, significant, near-instantaneous increases in luminance while viewing an HMD can result in visual discomfort. Therefore, the current study investigated the luminance change necessary to induce this discomfort. Based on the psychophysical experiment data collected from 10 subjects, a prediction model was derived using four complex images and one neutral image, with four to six levels of average scene luminance. Result showed that maximum area luminance has a significant correlation with the discomfort luminance level than average, median, or maximum pixel luminance. According to the prediction model, the discomfort luminance level of a head-mounted display was represented as a positive linear function in log(10) units using the previous adaptation luminance when luminance is calculated as maximum area luminance

Public HMDs: Modeling and Understanding User Behavior Around Public Head-Mounted Displays

Head-Mounted Displays (HMDs) are becoming ubiquitous; we are starting to see them deployed in public for different purposes. Museums, car companies and travel agencies use HMDs to promote their products. As a result, situations arise where users use them in public without experts supervision. This leads to challenges and opportunities, many of which are experienced in public display installations. For example, similar to public displays, public HMDs struggle to attract the passer-by's attention, but benefit from the honeypot effect that draws attention to them. Also passersby might be hesitant to wear a public HMD, due to the fear that its owner might not approve, or due to the perceived need for a prior permission. In this work, we discuss how public HMDs can benefit from research in public displays. In particular, based on the results of an in-the-wild deployment of a public HMD, we propose an adaptation of the audience funnel flow model of public display users to fit the context of public HMD usage. We discuss how public HMDs bring in challenges and opportunities, and create novel research directions that are relevant to both researchers in HMDs and researchers in public displays