Patent ID: 7697203
Filing Date: 2010-04-13
Classification: H04N

Abstract:
1. A stereoscopic display comprising: a display device that produces images for left and right eyes; a first polarization plate that receives the images and transmits light having a given polarization direction from the received images; a parallax barrier unit that comprises first and second polarization grating screens facing each other, and receives the light having the given polarization direction transmitted from the first polarization plate, and a second polarization plate which faces the parallax barrier to receive light output from the parallax barrier unit, and transmits only light with the given polarization direction among the light transmitted through the parallax barrier unit, wherein each of the first and second polarization grating screens has a grating pattern comprising a plurality of rows, and each row comprises a plurality of first birefringence elements and a plurality of second birefringence elements which change polarization directions of incident light in different directions, respectively, wherein, in each of the first and second polarization grating screens, the first and second birefringence elements are disposed alternately to each other in both horizontal and vertical directions, and each row comprising the alternatively disposed first and second birefringence elements is shifted with respect to a previous row by a given horizontal distance, so that the second birefringence elements abutting the first birefringence elements in the previous row are shifted with respect to the first birefringence elements by the given horizontal distance, and the alternate disposition of the first and second birefringence elements in the vertical direction constitutes a stepped pattern, and wherein the parallax barrier unit is configured to move at least one of the first and second polarization grating screens with respect to the other in at least one direction of the horizontal and vertical directions, thereby outputting the images from the second polarization plate in a two-dimensional (2D) mode or in a three-dimensional (3D) mode, wherein, in the 2D mode, the images are output as 2D images from the second polarization plate by causing the first and second birefringence elements of the first polarization grating screen to face the second and first birefringence elements of the second polarization grating screen, respectively, and thus, substantially all of light transmitted from each of the first and second birefringence elements of the first polarization grating screen to be input to each of the second and first birefringence elements of the second polarization grating screen, respectively, and wherein, in the 3D mode, the images are output as 3D images from the second polarization plate by causing the first and second birefringence elements of the first polarization grating screen to face the second and first birefringence elements of the second polarization grating screen, respectively, in a misaligned manner, and thus, substantially only part of light transmitted from each of the first and second birefringence elements of the first polarization grating screen to be input to each of the second and first birefringence elements of the second polarization grating screen, respectively, so that in combination of the second polarization plate, a plurality of apertures is formed.