High-resolution dynamic infrared scene projection using a reflective mosaic image combiner

The present limit on the number of display elements (dixels) that can be fabricated on one suspended membrane resistive infrared emitter array is just over 250,000. There is an increasing demand for simulated infrared (3 - 5 micrometers and 7 - 12 micrometers ) scenes made up from two to four times that many elements in order to increase the radiation. A method for increasing the apparent number of dixels in a dynamic IR image has been developed using a reflective mosaic image combiner. The heart of the image combiner is a wedge-shaped mirror with a razor-sharp edge. An experiment involving two arrays and one mirror was conducted to verify the basic concepts, and the results of that experiment are reported. The tasks of overcoming the many difficulties involved in making the mosaic image appear to be free of artifacts are discussed. The primary source for difficulties are the mirror, the alignment of the images of the arrays to the mirror, the temperatures of the projected scenes, the individual emitter arrays, and the ability of nonuniformity correction to compensate for radiance decreases at the mosaic seam(s). This mosaic image combiner technique is important to the US Army STRICOM because they are sponsoring the construction of the Dynamic Infrared Scene Projector (DIRSP) for use at the Redstone Technical Test Center. One of the requirements of DIRSP is to project high fidelity images with high spatial resolution. The mosaic image combiner described in this paper is a relatively low risk approach meeting that requirement using existing state of the art emitter arrays.