of the non burning time of sample 8 in the calculation next a second embodiment of the invention will be described below in this embodiment each of the wire grid type reflective polarizer 211 absorptive polarizer 212 and optical compensator 213 of sample 8 is mounted rotatable in a plane perpendicular to their common optical axis which is perpendicular to the lcd panel 215 by properly rotating the wire grid type reflective polarizer 211 and absorptive polarizer 212 the contrast ratio of the polarizers improves to about 1660 1 the improvement is attributed to the perfect alignment of the light transmission axes of the wire grid type reflective polarizer 211 and absorptive polarizer 212 by the rotation by further adjusting the rotational position of the optical compensator 213 the uniformity in luminosity of the display screen is improved particularly the uniformity of the black screen is greatly improved specifically the values of cie chromaticity coordinate x y indicative of the uniformity of a screen is improved from a pre adjustment value of 0 042 0 076 to a post adjustment value of 0 026 0 044 instead of rotating both of the reflective polarizer 211 and absorptive polarizer 212 substantially the same result can be obtained by solely rotating one of them it is noted that the optical compensator can be mounted at an angle relative to the optical axis as disclosed in the japanese patent application laid open no 2006 39087 moreover the optical compensator is not limited to the incidence side of an lcd panel for example a further optical compensator can be separately mounted on the light exiting side of the panel as.