PWM digital pixel sensor based on asynchronous self-resetting scheme

被引:38
作者
Kitchen, A [1 ]
Bermak, A
Bouzerdoum, A
机构
[1] Edith Cowan Univ, Sch Engn & Math, Joondalup 6027, Australia
[2] Hong Kong Univ Sci & Technol, Dept Elect & Elect Engn, Kowloon, Hong Kong, Peoples R China
基金
澳大利亚研究理事会;
关键词
asynchronous self-reset; CMOS imagers; pulse-width modulated (PWM) pixel; vision sensor;
D O I
10.1109/LED.2004.831222
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
In this letter, a pulse-width modulated digital pixel sensor is presented along with its inherent advantages such as low power consumption and wide operating range. The pixel, which comprises an analog processor and an 8-bit memory cell, operates in an asynchronous self-resetting mode. In contrast to most CMOS image sensors, in our approach, the photocurrent signal is encoded as a pulse-width signal, and converted to an 8-bit digital code using a Gray counter. The dynamic range of the pixel can be adapted by simply modulating the clock frequency of the counter. To test the operation of the proposed pixel architecture, an image sensor array has been designed and fabricated in a 0.35-mum CMOS technology, where each pixel occupies an area of 45 x 45 mum(2). Here, the operation of the sensor is demonstrated through experimental results.
引用
收藏
页码:471 / 473
页数:3
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