Patent ID: 6331887
Filing Date: 2001-12-18
Classification: G01B,G01C

Abstract:
An outdoor range finder for finding a distance to an object, comprising:a laser emitting means that emits a pulse laser beam to an object to be measured;an image reading means that takes in a plurality of images of the object synchronously with emission periods and off periods of the laser beam;a means for producing a plurality of differential images from differences between ones of the images read during the emission periods and other ones of the images read during the off periods;a means that detects minimum value data of corresponding pixels of said plurality of differential images;a means that determines a binary threshold from the minimum value of the differential images;a means that makes a binary data from the minimum value data of the differential images, and detects a position where the laser beam is received; andmeans for determining a distance between said laser emitting means and said object based on the position where the laser beam is received.