二维数字阵列光电位置敏感器件新式结构研究

Research of a novel architecture of a 2D digital array working as position sensitive detector

简要阐述光电位置敏感器件的特点、工作原理,根据光电位置敏感器件的原理和光电位置方程,分析了背景光与测量精度的关系。在此基础上,利用低峰探测仪的双极性三极管将像素M(i,j)的行与列位线联系起来,用来检测最大光强度的像素,显示出最低输出电压,使位线与其输出电压相对应;采用分布图像的峰值检波器来模拟预处理光电信号,通过数字转换得到图像的重心位置;采用集中平行的模拟计算估算射到感光区的光分布的重心,并通过时钟比较器得到数字化图像。给出了检测位置的二维光电传感器阵列、显示与图像数量的平方根成正比功耗关系式以及几个重要结论。

In this paper, principle and characteristics of the Position Sensitive Detector （PSD） are introduced. The relation of background light and the surveying precision are analyzed on the basis of the principle and the equation of PSD. The pixel M （i,j） is connected to the row and column bit-line by means of tow bipolar transistors working as distributed low peak detectors. The pixel, which detects the highest light intensity among its bit-lines, exhibits the lowest output voltage. The photo-generated signal is analog preprocessed using means of a distributed image peak detector; contour digitization for extracting the image centroid position. The sensor implements an analog intensive parallel computation for the estimation of the centroid on the photosensitive area. The voltage on each bit-line is compared with the normalized threshold by clocked comparator obtaining digitized images. A novel architecture of 2D digital array working as position measurement is presented and power consumption is proportional to the square root of the number of pixels.