Time-sequential color separator and liquid crystal projector using the same

Claim 1

A fast time-sequential color-separating device including a plurality of modules sequentially connected to each other, in which each module includes a dichroic mirror, which can pass a certain wavelength range of light having a first polarization and reflect the other wavelength range of light having a first polarization, a polarizing beam-splitter for said certain wavelength range and a liquid crystal panel that can change the polarization of a light reflected by the liquid crystal panel if an external electric field is applied thereto, wherein the light having a first polarization reflected by the liquid crystal panel is reflected along the incident optical path while no external electric field is applied to the liquid crystal, the light having a first polarization reflected by the liquid crystal panel becomes a light having a second polarization if an external electric field is applied thereto, the light having a second polarization is then reflected by the polarizing beam splitter and is emitted along a direction that is orthogonal to the incident light, various modules passing various wavelength ranges are connected one by one, an external electric field is sequentially applied to the liquid crystal panel of each module, so that various wavelength ranges of lights having a first polarization is turned to lights having a second polarization and are sequentially emitted along the direction orthogonal to the incident light.