Patent ID: 7905600

Claim:
An imaging unit, for a projection engine for or with reflective display devices, comprising: a first spectral selective splitting and/or illumination part to provide and/or receive essentially white light, split up said essential white light, of a first or s-polarized polarization state, into a first spectral component and a third and fourth spectral component, each spectral component being essentially complementary to the sum of the remaining two spectral components with respect to said essentially white light, change a polarization state of the fourth spectral component into an essentially orthogonal polarization state from said s-polarized into a p-polarized polarization state, and recombine said third and fourth spectral component in a spatially coincident manner into a second spectral component; and a second spectral and polarization selective splitting and/or illumination part to receive said first and second spectral components in a spatially separated manner and under non-coincident angles or a non parallel manner, said second spectral component comprising said third and fourth spectral component, wherein a polarization state of said third spectral component is essentially orthogonal to said polarization state of said fourth spectral component, said third spectral component being s-polarized and said fourth spectral component being p-polarized, split up said second spectral component into a third spectral component and a fourth spectral component being essentially complementary to said third spectral component with respect to said second spectral component, generate first, second, and third partial images of an image to be generated and/or to be reproduced using said first, third, and fourth spectral components, respectively, and recombine said first, second, and third partial images to a recombined image being representative of an image to be generated and/or to be reproduced, wherein said second spectral and polarization selective splitting and/or illumination part comprises a dichroic beam splitting device and first and second polarization selective or polarizing beam splitting devices, a wavelength selective polarizer is provided between a second surface of said second polarization selective or polarizing beam splitting device and said dichroic beam splitting device, said wavelength selective polarizer is configured to transmit a p-polarized part of said second partial image, said wavelength selective polarizer is configured to transmit an s-polarized part of said third partial image, and said wavelength selective polarizer is configured to block a p-polarized part of said third partial image.