接触式图像传感器噪声抑制方法研究

Noise Suppression Technique for Contact Image Sensor Based on Correlated Double Sampling

介绍了接触式图像传感器(CIS)的简要原理和存在的噪声类型,阐述了用相关双采样来消除这些噪声的机理,分析了CIS要求的驱动信号CP、SP和采样保持信号SH1、SH2之间的时序关系,并用复杂可编程逻辑器件(CPLD)来产生这几个信号。分析了相关双采样电路的工作原理,在此基础上进行了实验。实验表明,用相关双采样抑制CIS中的噪声,能够得到较为满意的结果。

The principle of contact image sensor (CIS) and the noise types existed in CIS were briefly introduced. The theory of suppressing these types of noise in CIS was described by using correlated double sampling(CDS), and the timing relationship between driving signals CP/ SP that CIS required and sampling-holding signals SH1/SH2 was also analyzed, these signals were produced by using complex programmable logic device(CPLD). The circuit principle of CDS was analyzed,and experiment of suppressing noise in CIS based on CDS was carried out. The experiment shows that satisfactory results can be obtained by using the technique of suppressing noise in CIS based on CDS.