| 摘要 |
PROBLEM TO BE SOLVED: To obtain bright display without lowering contrast in a reflection type display device by arranging an optical element changing linearly polarized light to circularly polarized light under a polarized light separating device. SOLUTION: The optical element 103 changing the linearly polarized light to the circularly polarized light is arranged under the polarized light separating device 102. The device 102 reflects the linearly polarized light in a direction perpendicular to a paper surface and transmits the linearly polarized light in a direction parallel with the paper surface, and it is arranged to function in such a way. A 1/4 wavelength plate is used as the optical element 103 changing the linearly polarized light to the nearly circularly polarized light, and is arranged so that an angle formed by the lag axis of the 1/4 wavelength plate with the direction of the linearly polarized light transmitted through the device 102 may be about 45 deg.. By such constitution, even when the circularly polarized light emitted from the optical element 103 is reflected and made incident on the optical element 103 again for some reason, the circularly polarized light becomes the linearly polarized light and is not transmitted through the device 102, and the lowering of contrast is prevented. |
