Investigation Of The Real-time Three-dimension Spatial Display System

Three dimension Display technology benefits from the recent developments in the fields of computer-generated hologram (CGH) technology and embedded systems. This contribution explores this three dimension display hardware system based on Open Multimedia Application Platform (OMAP5910), the architecture of Dual-Core Processor including ARM 925 RISC GPP and TMS320C55X DSP. MPU is used to be responsible for controlling and the interface-pin's configuration and controlling register etc. and DSP is mainly used to realize the image processing. This system makes the best of the features of three units of CGH, Real-Time Operation system (RTOS) and the hardware development platform, cutting down and revisingμC/OS-Ⅱsystematic kernel structure, completing the transplanting OS to the ARM core, making codes as effective as possible and reducing program algorithms. This paper firstly realizes the three dimension display under offline state.This paper introduces the hardware design and software development. The hardware design of this system includes four parts: three dimension display images capturing module, images processing module, LCD display module and projection display module. Software development is consisted of the transplanting of OS, the edit, loading and running of embedded application program, and LCD driver program development.At present, the technology of realizing the dynamic hologram three dimension display has become a research hotspot under the utilization of CGH images and program controlled liquid crystal spatial light modulators (LC-SLM).First of all, this paper proposes one CGH method which makes use of the liquid crystal spatial light modulators (LC-SLM) diffraction characteristics, to increase the reproduction perspective through the recorded objects appropriate pretreatment. The method is first to pre-process the object waveform information beyond the SLM perspective permitted scope, after pretreatment make the object waveform perspective meet the sampling theorem; and then to perform computer-generated hologram coding. The processing of three dimension holographic image data of the space-ray diffraction is first to be simulated by the application software MATLAB. Through simulation, the optimization calculation is found, and a suitable balance between the image processing speed and the image resolution is found. This system makes the processing of the recorded object waveform information, capturing the corresponding 2D images.Processing AD transfer, three angles images are processed based on new efficient CGH coding technology and the digital lasers' dynamic wave-front transforming technology of high resolution micro-display, and then to calculate CGH, sampling, calculating and encoding must be done.Next, this paper designs one kind of USB interface circuit based on the OMAP5910 USB function module. This system uses the USB interface to realize the CGH image signals'high-data communication between OMAP5910 and the host computer. The OMAP hardware platform is consists of three parts: ARM core, DSP core and Traffic Controller (TC). Three parts can independently calculate clock management. In the image processing module, the ARM925MPU core is good at main controlling and interface processing, and supports the hardware frame of the operation system platform. It is also used to transfer data, realizing dual-core communication with DSP, display image, the interrupt interface, the external controller interface and the RTOSμC/OS-Ⅱtask management. The transferred signals are in need of being processed in the way of acquisition, transform, filtering, estimation, reinforcement, compression and recognition, etc. in digital form. At the same time, we need increasing the transforming speed greatly as much as possible in order to improve the display images refresh speed and decrease vibration. DSP core has the faster speed of processing. In the Dual-core communication, the data quantity of the collected 3D holographic images is much larger, and the ARM and DSP tasks are relative larger, so we use mailbox register to transfer the dual-core handshake protocol and use DSP DMA to realize the larger quantity transmissions. In this way, we can reduce the burden of the DSP CPU,shorten the data processing time and improve the whole system running efficiently. The DSP/BIOS bridge combines GPP OS with DSP OS, making GPP customer transfer information and data with DSP task. GPP application program communicates with DSP arithmetic based on DSP/BIOS.Finally, the image data is putting up the display driver circuit of the XGA LCD projector based on the related SONY integrated chips. I2 C Bus is integrated in the chips without other interface circuit. The CGH coded images by S/H circuit display on the LCD, and pass by the optics system,being projected on the screen to realize 3D images display.ARM is adept in controlling and DSP is adept in complicated data calculation. This system makes full use of the characteristics of the two cores. At the same time, DMA transmission releases the DSP from the heavy processing tasks, shortening the data processing time. A new type 3D display module is built based on CGH, OS and OMAP platform.The LCD's resolution and contrast ratio are being continuously improved, the function of processor is also rapidly improved and CGH technology is being increasingly perfected. These lay the foundation for the CGH and 3D display's further application in the fields of biological sciences, medicine, terrain reconnaissance and military etc.