Abstract: A phase shifter is provided, which includes a first substrate, a second substrate, a liquid crystal layer, a plurality of first ring-shaped electrodes and a plurality of second ring-shaped electrodes. The first substrate and the second substrate are disposed opposite to each other. The liquid crystal layer is disposed between the first substrate and the second substrate. The plurality of first ring-shaped electrodes are disposed sequentially and in interval on a side of the first substrate close to the liquid crystal layer. The plurality of second ring-shaped electrodes are disposed sequentially and in interval on a side of the second substrate close to the liquid crystal layer. A plurality of vertical projections, projected by the plurality of first ring-shaped electrodes to the second substrate, and at least partially overlapped with the plurality of second ring-shaped electrodes, respectively.

Abstract: A three-dimensional (3D) image apparatus is provided. The 3D image apparatus includes a display unit, a front camera, and a processor. The front camera captures an image of the eyes of the user. The processor is coupled to the display unit and the front camera. The processor determines the position of the eyes of the user based on the image of the eyes of the user, and determines whether to display a 3D image or a two-dimensional (2D) image on the display based on the position of the eyes of the user.