Head-Mounted Display Optics With Cholesteric Light Recycling

The patent implements a light recycling mechanism where the absorption-type polarizer discards unwanted polarized light while the cholesteric liquid crystal layers reflect and redirect the discarded light back into the optical path. This allows the system to recover and reuse light that would otherwise be lost, thereby improving overall light efficiency and brightness without requiring a change in the polarizer type

The cholesteric liquid crystal layers serve as intermediary elements between the light emitting device and the absorption-type polarizer. These layers selectively reflect circularly polarized light of specific wavelengths while transmitting other wavelengths, acting as a mediator that directs light flow to maximize utilization and compensate for the light absorption caused by the polarizer

The patent divides the light management function into multiple specialized cholesteric liquid crystal layers, each segment handling a specific wavelength range. The first cholesteric liquid crystal layer targets red wavelength light, the second layer targets green wavelength light, and the third layer targets blue wavelength light. This segmentation allows each layer to be optimized for its specific function while collectively achieving comprehensive light efficiency improvement across the visible spectrum

The multiple cholesteric liquid crystal layers perform multiple functions simultaneously: they act as wavelength-selective mirrors, circular polarization converters, and light guides. Each layer reflects specific wavelengths while transmitting others, and collectively they manage the full visible spectrum, demonstrating multi-functionality that justifies the increased structural complexity

The optical system employs a nested arrangement where the first curved lens and second curved lens are positioned in sequence along the optical path, with the second lens effectively nested within the optical footprint of the first. The retardation plates and reflective polarizing plates are integrated within the lens structures themselves rather than being separate external components. This nesting minimizes the overall thickness by stacking optical functions in a compact configuration

The patent utilizes the third dimension (depth/thickness) efficiently by arranging optical elements in a layered configuration along the optical axis rather than spreading them out laterally. The curved lenses provide focal power in one dimension while the retardation plates and polarizing plates operate in perpendicular polarization dimensions, allowing multiple optical functions to coexist in a compact volume without significantly increasing device thickness