Patent ID: 6738131
Filing Date: 2004-05-18
Classification: G01C,G01S,G02B

Abstract:
A distance measuring method for measuring a distance from an imaging element to an object by optically taking in an image of the object using said imaging element, comprising:making light from an object at a known distance from said imaging element pass through light passing positions that are different from each other so as to project the light on an image forming plane of said imaging element, respectively; obtaining a displacement on the image forming plane between the images projected through said different light passing positions, said displacements being obtained by changing the distance from said imaging element to the object; pre-storing information showing a one-to-one correspondence between the known value of distance from said imaging element to the object and said displacement; making light from an object, of which a distance is to be measured, pass through said different light passing positions to project the light on said image forming plane of said imaging element, respectively; detecting a displacement on the image forming plane between the images projected through said different light passing positions; obtaining a distance from said imaging element to said distance-measured object corresponding to said detected displacement from said information showing the one-to-one correspondence between the distance from said imaging element to the object and said displacement; preparing a plurality of sets of said different light passing positions, and pre-storing information showing the one-to-one correspondence between the known value of distance from said imaging element to the object and said displacement for each of said sets; making light from an object, of which a distance is to be measured, pass through said plurality of sets of different passing positions to project the light on said image forming plane of said imaging element, respectively; detecting a displacement on the image forming plane between the images projected through each set of said different light passing positions; obtaining a distance from said imaging element to said distance-measured object corresponding to said detected displacement from said information showing the one-to-one correspondence between the value of distance from said imaging element to the object and said displacement for the corresponding set of the passing positions; and obtaining a distance of said distance-measured object by statistically processing said distances individually for said sets.