Development Of High-speed Linear CCD Image Acquisition System

Linear charge-coupled devices are widely used in aerospace, military and industrial inspection. Industrial color selection needs high-speed real-time image acquisition. It has raised a high performance requirement for selection of the CCD, analog front-end, driver circuit as well as interface configuration and design. Linear array CCD with its low cost, high resolution advantages is particularly suitable for line scan images of the design. The research and design of linear array CCD based on color selection has important reference value for industrial image acquisition system in high performance industrial color sorter development.In this paper, the linear CCD image acquisition system theory is reviewed, including CCD sensor working principle, main characteristics of the output signal, and the main content of characteristics of analog front-end technology.According to industry requirements, a color selection system is designed based on high-speed linear CCD image acquisition system. The system is actually divided into five parts: CCD drive clock design, the voltage amplitude modulation circuit design, CCD output signal conditioning, analog front-end circuit design and post-acquisition image signal transmission. The CCD output signal is conducted by the integrated analog front end, including correlated double sampling, black level clamp, gain and sampling rate of 12-bit analog-digital conversion. Finally the image data is transferred through Camera Link interface. The core component of the system composed of an ALTERA low cost FPGA. While the CCD drive clock, the analog front-end driven clock, and the Interface control is designed under the QUARTUSⅡdevelopment environment.The test results show that the performance has reached the advanced level of similar products. Compared with the traditional color sorter image acquisition system, the proposed system has a high degree of parallel processing, high integration, and simple circuit structure, and can achieve high-speed processing. It has the advantages of high accuracy color selection, fast data transfer rates and stable performance. The development of high performance industrial color sorter system has a promising application perspective.