High-sensitivity and wide-dynamic-range range finder and its applications

We propose a high-sensitivity and wide-dynamic-range position sensor for range finders using logarithmic-response and correlation circuit. The 3D measurement system using the proposed position sensor has advantages to applications, such as 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-to-background ratio). The minimum SBR of the sensor is - 14.4 dB lower than standard sensors. High sensitivity under - 10 dB SBR is realized in the dynamic range of 46 dB in terms of background illumination. Experimental results of position detection and 3D measurement in a strong background illumination are also presented.