Outdoor range finder

摘要

The present invention is a distance measuring device having a low power laser for use outdoors. The distance measuring device of the invention includes a laser emitting means that emits a pulsed laser beam to an object to be measured and an image reader that takes in irradiations images and stop period images of the object synchronously with an irradiation and stop period of the laser beam. A processing device then subtracts the stop image pixel values from the emission image pixel values to produce differential images. A minimum value image of the differential images is processed and binarized using a binary threshold to produce binary data from which a position where the laser beam is received is found. A calculation apparatus then determines a distance between the laser beam receiving position and the object based on the position where the laser beam is received.