Illumination system and display device including such a system
AssigneeU.S. Philips Corporation
InventorsAdrianus J.S.M. De Vaan, Paulus B.J. Schaareman
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Abstract
An illumination system comprising a reflector, a cholesteric filter and a depolarizer. The cholesteric filter is arranged between a radiation source and, in a display device, a display panel, and is selected to transmit radiation having a selected state of polarization in a selected wavelength range, while reflecting otherwise polarized radiation in that wavelength range. The depolarizer is disposed between the reflector and the cholesteric filter. Radiation reflected by the cholesteric filter is re-reflected to the filter by the reflector and, having been depolarized in the depolarizer, is transmitted to the extent it has the selected state of polarization in the selected wavelength.
Claims20
An illumination system for supplying an illumination beam having a selected state of polarization, which system successively comprises a reflector, a radiation source and a cholesteric filter, the filter active within the visible wavelength range, and a depolarizer arranged between the radiation source and the cholesteric filter.
Dependencies are inferred from the claim text.