Adaptive Optics Projection Unit Positioning for Image Size Control

The patent introduces a folding mirror to change the optical path from a linear arrangement to a folded geometry. This allows the projection unit to be positioned outside the space between the plane mirror and screen while maintaining a compact form factor. The folding mirror reflects light at an angle, effectively adding a spatial dimension to the optical path without increasing the physical distance between components.

The patent segments the optical system into independent modules: the projection unit, the folding mirror, the plane mirror, and the screen. By separating the projection unit from the fixed space between the plane mirror and screen, the system allows for greater flexibility in selecting and positioning the projection unit. Each component can be independently optimized and selected based on specific application requirements.

The patent employs a folding mirror with a specific geometric configuration that allows the optical path to fold back on itself. This curved/folded path enables the light to traverse a longer effective distance (for adequate image width) while occupying a compact physical space. The folding mirror's geometry creates an efficient space-utilizing optical path that maintains image quality without increasing apparatus thickness.