Ultraslim fixed pattern projectors with inherent homogenization of illumination
For a given illumination source brightness, the transmitted flux of common single-aperture projection optics scales with all three system dimensions, thus preventing the realization of slim devices along with a high lumen output. In this article we introduce a multichannel approach, called "array projector" which breaks this constraint, thus enabling the realization of ultraslim but high flux systems with inherent homogenization for still image content. The concept is based on regular two-dimensional arrangements of absorbing object structures and projective microlenses superposing their individual images on the screen. After deriving first-order scaling laws for the multichannel projector in contrast to common single-aperture optics, specification of system parameters is shown considering aberrations of a single-channel and collective effects of the array. The technological realization of a sample system is shown and characterized in terms of modulation transfer, homogeneity, depth of focus and flux.