Range finder for measuring three-dimensional geometry of object and method thereof

A three-dimensional image capturing method, employing:

• a projector unit for projecting pattern light onto an object;
• a first image capturing unit for capturing an image reflected from the object;
• a second image capturing unit for capturing an image reflected from the object;
• an identical principal point arrangement unit;
• and an imaging optical system;
• wherein the second image capturing unit is arranged so as to assume a principal point optically differing from that of the first image capturing unit;
• the identical principal point arrangement unit arranges the projector unit and the first image capturing unit at the position of an optically identical principal point;
• the imaging optical system is shared between the projector unit and the first image capturing unit;
• and the imaging optical system has a zooming unit;
• the method comprising:
• projecting the pattern light projected by the projector unit onto the object;
• capturing an image of the reflected light with the first and second image capturing units;
• measuring a three-dimensional geometry on the basis of a reflected image of the object acquired by the first image capturing unit and a reflected image of the object acquired by the second image capturing unit;
• and fixing a positional relationship between the principal point of the projector unit and that of the image capturing system when a zooming ratio has been changed by the zooming unit.

A three-dimensional image camera for measuring a three-dimensional geometry of an object, comprising:

• a projector unit for projecting pattern light onto the object;
• a first image capturing unit for capturing an image reflected from the object;
• a second image capturing unit for capturing an image reflected from the object;
• an identical principal point arrangement unit;
• an imaging optical system;
• and
• a housing;
• wherein
• the second image capturing unit is arranged so as to assume a principal point optically differing from that of the first image capturing unit;
• the identical principal point arrangement unit arranges the projector unit and the first image capturing unit at the position of an optically identical principal point;
• the imaging optical system is shared between the projector unit and the first image capturing unit;
• and
• the housing mounts the projector unit, the first image capturing unit, and the second image capturing unit;
• and
• a third image capturing unit for capturing the object in a visible light range;
• wherein
• the projector unit projects infrared light as pattern light;
• the first and second image capturing units acquire a reflected image of infrared light, to measure a three-dimensional geometry of the object;
• and
• the third image capturing unit acquires intensity data pertaining to the object.

A range finder for measuring a three-dimensional geometry of an object, comprising:

• a projector unit for projecting pattern light onto the object;
• a first image capturing unit for capturing an image reflected from the object;
• a second image capturing unit for capturing an image reflected from the object;
• an identical principal point arrangement unit;
• and
• an imaging optical system;
• wherein
• the second image capturing unit is arranged so as to assume a principal point optically differing from that of the first image capturing unit;
• the identical principal point arrangement unit arranges the projector unit and the first image capturing unit at the position of an optically identical principal point;
• the imaging optical system is shared between the projector unit and the first image capturing unit;
• the imaging optical system has zooming unit and is configured such that a fixed positional relationship between the principal point of the projector unit and that of the image capturing system exists when a zooming ratio has been changed by the zooming unit;
• the identical principal point arrangement unit further has a polarization conversion function for converting light originating from the projector unit into polarization light, and a polarization light direction selection function for selecting;
• and
• light to be guided to the first image capturing unit is selected from among light reflected from the object by the polarization conversion function.

A three-dimensional image capturing method, employing:

• a projector unit for projecting pattern light onto an object;
• a first image capturing unit for capturing an image reflected from the object;
• a second image capturing unit for capturing an image reflected from the object;
• an identical principal point arrangement unit;
• and an imaging optical system;
• wherein the second image capturing unit is arranged so as to assume a principal point optically differing from that of the first image capturing unit;
• the identical principal point arrangement unit arranges the projector unit and the first image capturing unit at the position of an optically identical principal point;
• the imaging optical system is shared between the projector unit and the first image capturing unit;
• and the imaging optical system has a zooming unit;
• the method comprising:
• converting light originating from the projector unit into polarization light by a polarization conversion function of the identical principal point arrangement unit;
• selecting a first light from among light reflected from the object, the first light being guided to the first image capturing unit by a polarization direction selection function provided in the identical principal point arrangement unit;
• selecting a second light from among light reflected from the object, the second light being guided to the second image capturing unit by a polarization direction selection unit provided in the second image capturing unit;
• measuring a three-dimensional geometry on the basis of a reflected image of the object acquired by the first image capturing unit and a reflected image of the object acquired by the second image capturing unit;
• and fixing a positional relationship between the principal point of the projector unit and that of the image capturing system when a zooming ratio has been changed by the zooming unit.

A three-dimensional image camera for measuring a three-dimensional geometry of an object, comprising:

• a projector unit for projecting pattern light onto the object;
• a first image capturing unit for capturing an image reflected from the object;
• a second image capturing unit for capturing an image reflected from the object;
• an identical principal point arrangement unit;
• an imaging optical system;
• a housing;
• wherein
• the second image capturing unit is arranged so as to assume a principal point optically differing from that of the first image capturing unit;
• the identical principal point arrangement unit arranges the projector unit and the first image capturing unit at the position of an optically identical principal point;
• the imaging optical system is shared between the projector unit and the first image capturing unit;
• the housing mounts the projector unit, the first image capturing unit, and the second image capturing unit;
• the identical principal point arrangement unit further has a polarization conversion function for converting light originating from the projector unit into polarization light, and a polarization light direction selection function;
• and
• light to be guided to the first image capturing unit is selected from among light reflected from the object by the polarization light direction selection function;
• and
• a third image capturing unit for capturing the object in a visible light range;
• wherein
• the projector unit projects infrared light as pattern light;
• the first and second image capturing units acquire a reflected image of infrared light, to measure a three-dimensional geometry of the object;
• and
• the third image capturing unit acquires intensity data pertaining to the object.