Patent ID: 7042535

Claim:
An optical shifter for periodically shifting an optical path of an outgoing light ray of a display panel, which represents an image frame, and thereby selectively displacing the image frame to one of three or more locations that are arranged in line on the same plane and that are spaced apart from each other by at least one pixel pitch, the optical shifter comprising: at least two pairs of elements that are arranged in series on the optical path of the outgoing light ray, each of said pair including a first element and a second element, which are arranged in this order such that the first element is closer to the display panel than the second element, the first element selectively changing a polarization direction of the outgoing light ray of the display panel, and the second element exhibiting one of multiple different refractive indices according to the polarization direction of incoming light; and a polarization corrector, which is disposed between the display panel and the first element that is closer to the display panel than any of the elements of the at least two pairs and which changes the polarization direction of the outgoing light ray of the display panel, the polarization direction being neither parallel to, nor perpendicular to, a direction in which the optical path is shifted, into a direction that is either parallel to, or perpendicular to, a direction in which the optical path is shifted.