Oral X-ray CCD Image Transmission System Design

With the development of CCD technology in digital fields,medical imaging has been widely used.Although the CCD imaging processors can process the image signal,the synchronization signal isn't transmitted in time ,and the conversion is slow,data can not be stored and transmitted to the PC timely,which make the study of the medical image inconvenient,so we re-design another CCD imaging processors in which we use the CLPD to generate the timing pulse,at the same time we use the MCU to make the synchronization signal reach the A/D converter and memory.Meanwhile we design USB interface which can transmit Real-time data.Thus it enables the image processing more efficiently,faster, better stability,and shorten the product developping time, lower the cost of CCD processor.The project is divided into three modules for the design.The first module is to achieve CCD pulse output, we use the CPLD devices EPM7128SLC84 to generate timing sequence pulses.According to the CCD timing requirements,the verilog lanuage is used to program, then it is compiled with QUARTUS II,at last it is simulated by Modelsim. Compared to the requirements of the timing sequence, the simulated timing sequence is in accordance with the required ones.The second module is to achieve CCD output analog signal conversion.Considering the various requirements,MAX187 is used to achieve A/D conversion. For the digital signals, a 4 M storage devices called AT45D041 is utilized, completing the signal conversion and storage.The third module is to establish efficient real-time data transmission, for which the USB interface design is carried out independently. The USB connection hardware schematic is layouted, and the programs for USB initialization and reading as well as writing process are developed.In this thesis, we introduced a system of hardware components,including timing pulse sequences of the design,A/Dconverter, data storage and USB interface design.The relevant knowledge and working principle are described,the circuit is designed completelyt.We complete the CCD signal processing and transmission system design which meets requirements of the project.