High-speed and continuous range finder system
Abstract This chapter presents a new type of high-speed and continuous range finder system based on the slit-ray projection method. One of the remarkable features of the system is the usage of a position-sensitive device (PSD) array as the image plane. Each PSD element is attached to a respective analogue signal processor, A/ D converter and memory element. In our method, the slit-ray is scanned at a constant angular velocity, and so scanning time is related to the directional information of the slit-ray. When the resultant slit-like image passes across the image plane, i.e. the PSD array, each element of it outputs analogue positional information of the slit-like image on it from time to time through the respective analog processor. This analogue signal is digitized by an A/D converter and stored in the respective memory element at a constant interval of the scanning time of the slit-ray. As a result, basic data for range computation are acquired during only one scanning of the slit-ray at high speed. If we use large capacity and/or dual-port memories, we may successively obtain range data of as many scenes as we want.