In the late 1920s, television was invented around cathode ray tube technology (CRT), whose use persisted throughout the 20th century. CRTs have almost disappeared in present-day technology, replaced by more innovative flat panel display technologies, such as plasma screens liquid crystal display (LCD), and liquid crystal on silicon (LCOS). Besides significant, recent advances in two-dimensional (2 D) displays, there have been considerable advances toward three-dimensional (3D) displays. The growing demands of 3D displays have stimulated significant research activity over the last several years, resulting in many notable achievements in areas such as stereoscopic, auto stereoscopic, volumetric, and integral imaging displays. Each display type depends on the mechanism being used to display the 3D image data. This in turn requires specific systems designed to fit the 3D image data formats. These systems are composed of software components, optical components, and devices, such as projectors, x-y optical beam scanners, stacks of LCD elements, microlens arrays, screens of various types, and the like.
A projector is a device that can be used to display an image or computer screen on a large projection screen. Several types of projectors are available in the market that are capable of displaying video signals and fixed pictures on projection screens. These projectors can be differentiated from each other according to the projection technology utilized and/or image resolution exhibited. The most recent 3D display mechanisms use high-speed spatial light modulators, such as digital light processors (DLP) or liquid crystal displays (LCD).
DLP is a revolutionary display technology that uses digital micromirror devices (DMD) to digitally control light beams. The DMD demonstrates significant success as a high-speed spatial light modulator in the projectors. In general, an image is created by switching micromirrors of the DMD such that each micromirror represents one pixel in the projected image. The number of micromirrors typically matches the resolution of the projected image. For example, 800×600, 1024×768, 1280×720, 1400×1050 and 1920×1080 matrices are some familiar DMD sizes.
The micromirrors of the DMD can be titled rapidly to reflect light either toward a projection lens or to a heat sink that absorbs light. The rapid steering of the micromirrors, essentially switching between ‘on’ and ‘off’) allows the DMD to change the intensity of the light being reflected out toward the projection lens, producing shades of grey in addition to white (‘on’ position) and black (‘oif’ position).
Conventional display resolutions for movable projectors, such as the DLP projectors, include super video graphics array (SVGA) 800×600 pixels, extended graphics array (XGA) 1024×768 pixels, SXGA+1400×1050, 720p 1280×720, and 1080p 1920×1080 pixels. For example, Texas Instruments (TI) Inc. has developed and manufactured a digital light processing board to provide the capability of controlling each individual micromirror from the DMD surface using a special language code, such as Visual C++.
In using a DLP projector, scientists and engineers desire the ability to render their own 2D images, 2D animation, 3D images, or 3D animation. Although these projectors are greatly suited for applications such as home theater entertainment and PowerPoint® presentations, they are not well suited for use in display research and development where precise control of individual micromirrors (or blocks of micromirrors) is desired. In scientific and research arenas, each time the user needs to control any individual micromirror over the DMD surface, the software code must be modified to execute these new changes. This in turn encumbers the user with additional time-consuming steps.