Patent ID: 7177015
Filing Date: 2007-02-13
Classification: G01C,G01S

Abstract:
1. A distance-measuring device, comprising a light source unit, one projecting optical system having a projecting light optical axis and for projecting the distance-measuring light from said light source unit to an object to be measured, a photodetection optical system having a photodetection optical axis and for receiving a distance-measuring light reflected from said object to be measured, and an internal reference optical system for guiding the distance-measuring light from said light source unit toward said photodetection optical system as an internal reference light, wherein said light source unit comprises one light source for emitting said distance-measuring light, a first optical path for projecting said distance-measuring light from said light source with a first spreading angle toward said object to be measured, a second optical path for projecting said distance-measuring light from said light source with a second spreading angle toward said object to be measured, said first spreading angle being larger than said second spreading angle, an optical fiber arranged on one of said first and second optical paths, and an optical path switching means for guiding said distance-measuring light selectively toward one of said first and second optical paths, and wherein said photodetection optical system has an optical filter which transmits light in a narrow wavelength range that includes the wavelength of said distance-measuring light.