Directional light beams for angle detection

摘要

An angular detection arrangement for a head mountable display (HMD) comprising a light source or reflective marking and an optical detector, one of the light source or reflective marking and the optical detector being disposed at the HMD and the other being disposed at a fixed point, the light source or reflective marking comprising a directional light source or reflective marking and a substantially non-directional light source or reflective marking such that the separation between the directional and non-directional light sources or reflective markings as detected at the optical detector is dependent upon the relative orientation of the HMD and the fixed point.

主权项

1. An angular detection apparatus for detecting pitch motion of a head mountable display (HMD), comprising:
an optically detectable feature selected from the group consisting of at least one of a light source and a reflective marking, the optically detectable feature comprising a directional optically detectable feature and a substantially non-directional optically detectable feature, the substantially non-direction optically detectable feature being viewable over at least a range of angles by which the directional optically detectable feature is viewable; an optical detector configured to detect a separation between the directional optically detectable feature and the substantially non-directional optically detectable feature, one of the optically detectable feature and the optical detector being disposed at the HMD and the other being disposed at a fixed point, the fixed point being fixed such that when the HMD is subject to pitch motion, the fixed point is not subject to the pitch motion; and an orientation detector in operative communication with the optical detector and configured to detect the pitch motion of the HMD from a relative orientation of the HMD and the fixed point in dependence upon the detected separation between the directional and substantially non-directional optically detectable features.