Waveguide AR Display Contrast Control Using Polarized Light

The patent implements dynamic light intensity adjustment by using a light intensity detection device to continuously monitor surrounding scene brightness and automatically adjusting the light transmission control device accordingly. This dynamic adaptation resolves the contrast mismatch problem while maintaining the compact waveguide structure, allowing the system to adapt to varying environmental lighting conditions without requiring larger or more complex optical components.

The patent changes the transmission parameter of the waveguide by introducing a controllable light transmission control device that can dynamically adjust its transmission rate based on detected light intensity. This parameter adjustment mechanism allows the system to optimize contrast ratio in real-time while preserving the inherent compactness of the waveguide design, effectively decoupling contrast performance from system volume.

The patent integrates multiple functions into the waveguide structure itself. The waveguide serves both as the core optical guiding component and as the mounting structure for the light intensity detection device and light transmission control device. The polarizer and polarization control element are incorporated directly into the existing optical path, allowing these components to serve dual purposes: maintaining the AR display function while simultaneously enabling dynamic contrast adjustment, thereby minimizing additional structural complexity.

The patent merges the light intensity detection function and light transmission control function into a unified control system that operates through a single integrated pathway. The detection device, control device, and waveguide are combined such that the control device receives input from the detection device and adjusts the waveguide transmission accordingly, creating a streamlined system that achieves contrast optimization without requiring separate, complex subsystems.

The patent employs periodic or dynamic switching of polarization states through the polarization control element. By periodically adjusting the polarization orientation in response to detected light intensity conditions, the system optimizes light transmission efficiency at different moments while maintaining overall contrast improvement. This periodic adaptation allows the system to minimize energy loss during varying environmental conditions rather than using a fixed polarization filter that would consistently block a portion of light.

The patent implements a feedback mechanism where the light intensity detection device continuously monitors the actual light transmission and contrast performance, then feeds this information back to the light transmission control device. This closed-loop feedback system allows real-time optimization of the polarization control parameters, adjusting the polarization filtering dynamically to achieve the minimum necessary light blocking for contrast improvement, thereby minimizing overall light transmission loss while maintaining effective contrast ratio.