Patent ID: 6803593
Filing Date: 2004-10-12
Classification: G01C

Abstract:
A distance measuring system for measuring distance by receiving a reflection light beam from an object to be measured, comprising a control arithmetric unit, a storage unit, a light emitting unit for emitting a measuring light beam, a photodetection unit for receiving said reflection light beam from said object to be measured and for issuing a signal based on a photodetection amount of said reflection light beam, a light amount adjuster for adjusting an amount of light entering said photodetection unit, a mode changing switch, and a display unit for displaying the result of a calculation of said arithmetic unit, wherein said mode changing switch selects whether said object to be measured is a prism or a natural object, said storage unit prestores a photodetection amount of a reflection light beam from the prism according to the distance and a photodetection amount of a reflection light beam from the natural object according to the distance, said light amount adjuster adjusts the photodetection amount of said reflection light beam received by said photodetection unit at an approximately constant amount and obtains an amount of the reflection light beam based on the result of the adjustment, said control arithmetic unit compares the obtained amount of the reflection light beans and the photodetection amount of said reflection light beam from said prism or said natural object that is prestored in said storage unit, and judges whether said object to be measured is the selected object to be measured based on the result of the comparison, and said display unit displays the result of said judgment by said control arithmetic unit.