High-Sensitivity and Wide-Dynamic-Range Position Sensor Using Logarithmic-Response and Correlation Circuit

Abstract

SUMMARY We propose a high-sensitivity and widedynamic-range position sensor using logarithmic-response and correlation circuit. The 3-D measurement system using the proposed position sensor has advantages to applications, for example a walking robot and a recognition system on vehicles, which require both of availability in various backgrounds and safe light projection for human eyes. The position sensor with a 64 × 64 pixel array has been developed and successfully tested. We describe the sensitivity of position detection as SBR (Signal-toBackground Ratio). The minimum SBR of the sensor is −13. 9d B lower than standard sensors. High sensitivity under −10 dB SBR is realized in a dynamic range of 41.7 dB in terms of background illumination. Experimental results of position detection and 3-D measurement in a strong background illumination are also pre