| 摘要 |
<p>Switchable holographic optical elements (HOEs) (320) that can be turned on and off are used in systems and methods for projecting 3-D images, or for projecting 2-D tiled images with increased size and/or resolution. In one embodiment, the method projects monochrome 3-D images through the steps of (a) displaying, at an object plane (310), a 2-D image (306; 307; 308) that is a cross section of a 3-D image, (b) activating an HOE (302) to focus the 2-D image onto an appropriate image plane (331; 332; 333; 334), and (c) repeating steps (a)-(b) for different cross sections of the 3-D image. Each of the cross sections is focussed onto a different image plane, so that the resulting images appear in an 'image volume' (330) as a 3-D image. Steps (a)-(c) are then rapidly repeated at a fast rate (such as 60 frames per second) to create a continuously displayed 3-D image (335). The 3-D image may be a static image or a moving image. In another embodiment, the method includes steps of sequentially displaying 2-D cross-sectional images, and, in synchronization, sequentially activating switchable HOEs that image the cross sections onto different image planes. Also described is a 3-D projection system that includes (a) a 2-D display configured to sequentially display a series of cross sections and (b) an HOE configured to focus the 2-D display onto a series of image planes at different distances from the 2-D display. The switchable HOEs are also used in an image projection system that projects an image composed of an array of 'tiles'.</p> |
