Abstract: A LCD device is provided. On the input side, the collimated-light generator generates collimated light from incident light and then, the first polarizer plate of the first polarized-light controller generates first polarized light from the collimated light. The first quarter wavelength plate of the first polarized-light controller generates second polarized light from the first polarized light. The second polarized light thus generated passes through the liquid crystal layer to reach the output side. On the output side, the second polarized light passes through the second quarter wavelength plate of the second polarized-light controller and the second quarter wavelength plate thereof. Thus, the polarization state of the second polarized light is returned to its original one.