It’s been a little more than a year since Microsoft started shipping its HoloLens head-mounted display to developers, and to this day the mixed reality headset remains the only self-contained device on the market. If HoloLens' technology probably remains years ahead of the competition, you can't deny that just like many other HMDs, it isn’t exactly compact and pleasing to wear all day.
It will probably be years before HMDs become compact enough to be much more comfortable as well as socially acceptable. In the meantime though, it appears that Microsoft is developing flat lenses that could include various sensors including an infrared emitter, an IR sensor and more. In April of this year, the company filed a patent for “Flat Lens Imaging Devices and Systems” that could be incorporated in head-mounted displays, offering a more compact footprint over a conventional curved optical lens such as the one found on the HoloLens (via MSPoweruser). Here is the patent description:
The flat lens may be combined with an infrared (IR) emitter, an IR sensor, or an image sensor, and/or one or more additional optical lenses or filters. The flat lens may provide a more compact footprint over a conventional curved optical lens. Additionally, the flat lens may be configured to bend light instantaneously, rather than gradually as the light passes through the lens. This may be advantageous in reducing the number of optical lenses within the electronic device and/or size (e.g., thickness) of the overall lens arrangement (as well as the size of the overall electronic device), therein allowing for a more compact configuration for the electronic device.
This technology could hopefully help Microsoft to create a more compact HoloLens in the future. Earlier this year, the company's research division unveiled a prototype near-eye holographic display in a sunglasses-like form factor which looked really impressive, though all of its driving electronics were external. The future of HoloLens looks definitely exciting, though a new model isn't expected until 2019.