Vehicle Lamp Apparatus Using Polarization Control

The patent changes the polarization parameter of the radiated light from unpolarized or randomly polarized to uniformly p-polarized light. By controlling the polarization state of the light, the reflection from water surfaces is minimized because p-polarized light at Brewster's angle has minimal reflection. This parameter change resolves the contradiction by maintaining illumination while eliminating glare.

The patent converts the harmful reflection effect into a beneficial selective reflection characteristic. By using p-polarized light, the system exploits the physical property that water surfaces reflect s-polarized light strongly but transmit p-polarized light. This converts the harmful glare effect into a useful selective transmission characteristic that illuminates the road without blinding oncoming drivers.

The patent segments the optical system into distinct functional components: a polarizing filter to separate p and s polarized beams, a reflecting mirror to redirect the transmitted s-polarized beam, and a wavelength plate to convert the s-polarized beam back to p-polarized. This segmentation allows each component to perform a specific function, making the complex polarization control achievable through modular design.

The patent introduces intermediate optical elements (the reflecting mirror and wavelength plate) to mediate the transformation of s-polarized light into p-polarized light. Instead of directly generating p-polarized light from the source, the system uses these intermediary components to convert the transmitted s-polarized beam, providing a flexible and controllable method to achieve uniform p-polarized output.