Illumination Optical Device for Projection Displays

The patent combines multiple light sources (2n light sources) into a unified illumination system through a series of optical combining elements. First light combiner optical systems merge pairs of light beams, then a second light combiner merges those combined beams, ultimately synthesizing all 2n light beams into a single consolidated illumination path that passes through the liquid crystal panel. This merging approach allows multiple light sources to contribute to brightness without proportionally increasing device volume.

The optical system employs a nested structure where multiple levels of light combining are integrated within a compact arrangement. The first light combiner optical systems are positioned to receive and combine light from the 2n light sources, then the second light combiner optical system is nested within this structure to further combine the already-combined beams. This nested arrangement of optical elements allows the system to accommodate multiple light sources in a space-efficient manner.

Instead of using a single high-power light source, the patent segments the illumination into 2n separate light sources, each operating at lower power. This segmentation allows for more efficient light collection and guidance from each individual source through the optical system. Each light source's beam is separately controlled and combined, reducing energy loss that would occur in a single high-power system due to heat generation and incomplete light collection.

The optical system is designed to continuously guide and combine light beams from all 2n light sources through a series of optical elements (collective optical systems, light combiners) without interruption or significant loss. The ellipsoidal mirrors and lens arrays ensure continuous light transmission and efficient synthesis of all light beams, maintaining high light utilization efficiency throughout the illumination path from each individual source to the final combined output.

The optical system employs universal optical elements that perform multiple functions. The collective optical systems serve both to focus individual light beams and to position them for subsequent combining. The light combiner optical systems not only merge light beams but also maintain proper optical alignment and focus. This multi-functionality of optical elements reduces the need for additional specialized components that would increase complexity.

The patent employs an asymmetric optical architecture where the light combining process follows a specific hierarchical pattern (2n sources → n first combiners → 1 second combiner) rather than a symmetric arrangement. This asymmetric design optimizes the optical path length and element positioning, allowing for more efficient space utilization and simpler alignment requirements compared to a symmetric multi-source configuration.