Abstract: A wearable display system includes one or more emissive micro-displays, e.g., micro-LED displays. The micro-displays may be monochrome micro-displays or full-color micro-displays. The micro-displays may include arrays of light emitters. Light collimators may be utilized to narrow the angular emission profile of light emitted by the light emitters. Where a plurality of emissive micro-displays is utilized, the micro-displays may be positioned at different sides of an optical combiner, e.g., an X-cube prism which receives light rays from different micro-displays and outputs the light rays from the same face of the cube. The optical combiner directs the light to projection optics, which outputs the light to an eyepiece that relays the light to a user's eye. The eyepiece may output the light to the user's eye with different amounts of wavefront divergence, to place virtual content on different depth planes.

Abstract: A wearable display system includes a light projection system having one or more emissive microdisplays, e.g., micro-LED displays. The light projection system projects time-multiplexed left-eye and right-eye images, which pass through an optical router having a polarizer and a switchable polarization rotator. The optical router is synchronized with the generation of images by the light projection system to impart a first polarization to left-eye images and a second different polarization to right-eye images. Light of the first polarization is incoupled into an eyepiece having one or more waveguides for outputting light to one of the left and right eyes, while light of the second polarization may be incoupled into another eyepiece having one or more waveguides for outputting light to the other of the left and right eyes. Each eyepiece may output incoupled light with variable amounts of wavefront divergence, to elicit different accommodation responses from the user's eyes.

Abstract: A belaying descending device for belaying a leading or second mountain climber, and for controlled descending along a single or double rope, including a metal body having a pair of slits at least one slit for the rope to pass through, a first opening in the form of a securing bow for receiving a first snap-hook in a manner that at least one loop of the rope may pass through the first snap-hook, a second suspension opening for receiving a second snap-hook in the case of belaying of the second climber, and fixed stop means transversely offset with respect to said openings for limiting the movement of the rope through the slits.

Abstract: A belaying descending device for climbing or mountaineering,