Importance

Loading Importance Indicators...

Abstract

A system for establishing a base between a light projecting station and a light receiving station of a triangulating coordinate finder incorporates a target on the light transmitting station and a reflector appropriately positioned relative to a photo sensitive receiving array in the light receiving station. A beam of light is directed through a peep hole through the target onto the reflector and is reflected back onto the target. By adjusting the relative orientation of the two stations so that the light beam is reflected back from the reflecting surface in a direction substantially co-axial with the beam of light projecting through the peep hole the bases of the two stations are arranged to be substantially in the same plane and on a base line. The base length between the two stations is measured and the orientation of the projected beam and the focal axis of the receiving station are established relative to the base line to provide coordinates for the triangulating coordinate finder. When scanning over long distances, or under conditions of varying ambient light and different colored background, the amount of light received in the light receiving station may vary due to conditions other than the change in distance. It is therefore preferred to threshold the signal received and use only those signals above a pre-determined threshold to establish accepted signals and to examine the overall signal and determine those areas where no accepted signal has been registered and rescan those areas using a slower scan rate, i.e. a longer illumination time (more light applied) per unit area per unit time of exposure or increase the exposure per unit area scanned.

Loading the Abstract Image...

First Claim