Progress in multi-channel optics for virtual and mixed reality head-mounted displays

Reducing the size of Virtual Reality head-mounted displays is of main interest to improve the comfort of users, which is a particularly complex design problem due to the very large field of view needed to feel the immersion. Such reduction can be achieve via folded polarization “pancake” optics, but at the expense of a very low transmission efficiency and poor contrast. High compactness without those drawbacks can be achieved by multichannel optics, whose design for high performance is carried out at LIMBAK intensively introducing freeform optical surfaces, adding variable magnification to maximize the VR display resolution where it is to be normally gazed, and applying two-dimensional distortion software corrections to each channel. This presentation will cover the recent advances in these systems, the growing variety of geometries, the benefits obtained when including gaze-tracking and the resolution boosts obtained by the application of pixel interlacing strategies.