Recently, there has been substantial progress in the development of ultra-compact image projection systems with dimensions clearly below the size of products based on DMDTM technology. This has been enabled by the availability of electrically modulated laser sources for all three elementary colors and a two-dimensional resonant micro scanning mirror as MOEMS device for light deflection. The laser beam formed by collimator optics is directed onto the micro scanning mirror. Then, the reflected beam describes a highly complicated Lissajous figure on the projection screen with flare angles of up to 20 degrees. By driving the mirror and electrically modulating the intensity of the laser beam in a synchronous manner, projection of images can be achieved. In this contribution we will present the theoretical background of the projection system as well as the latest achievements in system design. Both monochrome and full color systems are currently available. The latter use a separate laser bank as RGB light source, which is coupled with the projection head comprising the micro-optics and the micro scanning mirror. For monochrome red systems, the laser diode can be integrated into the projection head as well, whose volume could be reduced to 15mm x 7 mm x 5mm. All systems have VGA (640 x 480 pixels) resolution and operate with 8 bit color depth per pixel and 50 frames per second. This degree of miniaturization makes laser projection systems attractive for integration into mobile devices and overcomes limitations of display size in such appliances
This contribution presents an optical module for projection of still images and video sequences. It consists of a laser source, miniature collimator optics, and a special MEMS device, a two-dimensional resonant micro scanning mirror. The laser beam is focused onto the micro mirror by the collimator optics. The micro mirror reflects the beam onto the desired projection area with a flare angle of up to 15 degrees for both axes. Given the resonant oscillation of the mirror, the beam follows a Lissajous figure. By choosing appropriate oscillation frequencies, it can be ensured that the laser beam hits every pixel of a pre-defined geometrical image resolution at a given frame rate. Limitations result from mechanical stability of the mirror plate that has a typical diameter of 1 mm and the CMOS-compatible fabrication process of the MEMS device. Projection of images and video sequences is achieved by modulating the laser diode. An external electronics receives data and transforms it into necessary modulation signals. Since frequency and amplitude of oscillation of the micro mirror are highly precise, no electrical feedback from the mirror to the modulation electronics has to be implemented. The system can be operated in open-loop modus. Currently, a monochrome demonstrator with VGA (640 x 480 pixels) resolution and 50 frames per second has been realized. Because of the compact size of the mirror, integration into mobile devices is fairly easy
In this contribution, we demonstrate that the IEEE 1394 bus is well suited for data exchange in modern distributed industrial systems. Starting from an overview of the operation of the bus, we describe a generic system design for IEEE 1394 nodes and show the usability of this approach by means of real-world applications
Recently, there has been substantial progress in the development of ultracompact image projection systems. This has been enabled by the availability of electrically modulated laser sources for all three elementary colors and a 2D resonant microscanning mirror as a micro-opto-electro-mechanical system (MOEMS) device for light deflection. The laser beam formed by collimator optics is directed onto the micro-scanning mirror. Given the movement of the mirror, the laser beam scans the entire image area. By driving the mirror and electrically modulating the intensity of the laser beam in a synchronous manner, a projection of images can be achieved. In this contribution, we present the theoretical background of the projection system as well as the latest achievements in system design. Both monochrome and full-color systems are currently available. The latter uses a separate laser bank as an RGB light source, which is coupled with a projection head. For monochrome red systems, the laser diode can be integrated into the projection head as well, whose volume can be reduced to 15×7×5 mm. All systems have video graphics array (VGA) (640×480 pixels) resolution and operate with 8-bit color depth per pixel and 50 frames per second
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