Optical System Light Guide Member Prevents Image Leakage

The patent introduces a light guide member as an intermediary component that receives image light from the second optical system and guides it to the user's eye. The light guide member acts as a mediator that controls the propagation path of image light, preventing it from leaking in the opposite direction while ensuring it reaches the intended destination. The light guide member's waveguide structure confines the light within its core, preventing leakage.

The patent changes the propagation dimension of image light by transitioning it from free-space propagation through multiple optical systems to guided propagation within the light guide member. This dimensional change from unconfined to confined propagation (from 3D free space to 1D guided path) prevents leakage in the opposite direction while maintaining transmission to the user's eye.

The patent applies preliminary action by designing the optical path configuration before light propagation occurs. The first optical system forms an intermediate image at a specific position, and the second optical system is positioned and oriented to receive light from this intermediate image position. This preliminary arrangement ensures that light propagates in a single direction through the light guide member without back-and-forth movement, preventing energy loss from multiple reflections.

The patent replaces potential mechanical bouncing or back-reflection of light with a carefully designed optical path using reflective surfaces and the light guide member's waveguide structure. Instead of allowing light to mechanically bounce back and forth, the system uses controlled reflection at specific angles and the light guide's total internal reflection to maintain unidirectional propagation, improving energy utilization.