Method of reducing speckles in liquid-crystal display with coherent illumination

摘要

Disclosed is a method for reducing speckling in liquid crystal displays with coherent illumination. The method consists of providing a liquid-crystal display illuminated, e.g., with a laser light, in which the image is formed by passing the light through the light redirecting holographic elements arranged in a matrix pattern, then changing the direction of the beams emitted from the holographic elements by passing the emitted beams through the polarization-changing liquid crystal elements, and converting the image-carrying beams produced by the liquid crystal elements into a visible image by passing them to a viewer through a polarization analyzer.

主权项

1. A method of reducing speckles seen by a viewer in a liquid-crystal display with coherent illumination comprising the steps of:
providing a liquid-crystal display with coherent illumination comprising at least a matrix of holographic elements on light waveguides, a matrix of liquid crystal elements, a matrix of moveable micromirrors, and a polarization analyzer, where the matrices are packed together into a layered structure and where holographic elements, liquid crystal elements, and moveable micromirrors of the respective matrices are aligned and have substantially equal dimensions; producing an image that may contain a speckle pattern on the liquid crystal display by propagating the light along the waveguides to the holographic elements, emitting the light from the holographic elements in the form of beams toward the micromirrors, reflecting the beams from the moveable micromirrors toward a viewer through the respective liquid crystal elements thus changing polarization of the beams and converting them into beams that carry information; passing the beams that carry image information through the polarization analyzer, thus converting the beams into beams that carry a visible image; and repeating the image-producing step and the step of passing the beams through the polarization analyzer with reproduction of a speckle-pattern containing image; and averaging the speckles seen by the viewer by moving the moveable mirrors and thus reproducing the image each time in a different position.