Study On Real-time Measurement Using Linear CCD

With the development of integrated circuit MOS, as a new type of integrated circuit MOS is CCD device, it also get rapid development and wide application. CCD device is a kind of congealing device, it has small volume, light quality, low power consumption, high reliability, long life, high spatial resolution of many advantages. With decades of development, the CCD is widely used in various fields, involved in aerospace, broadcast video, industrial vision, size measurement and many other fields.In order to improve the measurement precision of the linear CCD, this article designes a low noise measurement system, which analysis processing system noise from two aspects of hardware and software. The analog signal of CCD output transmission to the AD, after the correlated double sampling process to reduce the reduction noise. The converted digital signal transmit to the FPGA, after denoising by the low pass filter, the data transmit to the computer from the internal cache of the FPGA.In this paper, the system noise are analyzed in detail, and according to these noise filtering method was given in this paper. For CCD signal noise, we use correlated double sample process. For the power supply noise, we use the EMI filter. For the interaction of digital earth and simulate earth, we use the resistance of zero to isolate. For the high frequency of digital signal noise, we use a low-pass filter.System software design includes sequential function module, filter function module and data transmission function module. Designing the drive of CCD and AD normal operation uses Verilog HDL language. The matlab software combined with the FPGA design is suitable for the low pass filter. The digital signal after filtering is embedded into the memory cache, and parallel data is transfered into serial data. Finally they display on the upper computer via a serial port.We need to test the performance and precision of the system. We bulid a double slit diffraction experiment platform, to boserved the received CCD time domain signal. Experiments show that this system has good noise control, and the original goal is achieved.