摘要
在应用CCD视频信号集成处理器(视频处理器)的相机系统中,在目标亮度不变的情况下,当增益参数设置较大时,视频处理器的暗电平自动校正过程会导致CCD图像在开始阶段出现灰度值"渐变"和"突变"现象。以EXAR公司XRD98L59为例,对视频处理器内部结构和暗电平自动校正的工作过程进行分析,建立了暗电平自动校正过程的数学模型,通过实验确定了各项参数的值。根据模型计算结果,将相机系统准备时间调整为5s,解决了CCD图像在开始阶段灰度值"渐变"和"突变"的问题。
In a camera system of CCD as sensor and utilizing CCD video signal integrated processor （video signal processor for short）,when gain is high,the black level auto-correction process of video signal processor will cause CCD image gray value vary slowly and sharply at the beginning stage with target brightness not varying.Based on XRD98L59 of EXAR,this paper analyzes the device structure and its black level auto-correction process,establishes the model of black level auto-correction process,determines the parameters by experiment,and verifies the correctness of the model.According to the calculating results of the model,the preparing time of the camera system is adjusted to 5 s,the problem that CCD image gray values vary ＂slowly＂ and ＂sharply＂ at the beginning stage is resolved.
出处
《液晶与显示》
CAS
CSCD
北大核心
2010年第6期879-883,共5页
Chinese Journal of Liquid Crystals and Displays
关键词
CCD
视频处理器
暗电平
自动校正
CCD
video signal processor
black level
auto-correction
