Three-dimensional measuring system and method of measuring the shape of an object

A three-dimensional measuring system for measuring a shape of an object, said three dimensional measuring system comprising:

• an optical mechanism for emitting a light that illuminates the object, and optically scanning the object;
• an image pickup sensor for receiving light reflected from the object, said image pickup sensor having an image pickup surface including a plurality of light-receiving regions across which the reflected light traverses;
• a scanning device for changing a direction in which said light illuminates said object;
• an image pickup control device for driving said image pickup sensor to output information indicating an amount of the reflected light incident on each of said light-receiving regions over time;
• a first arithmetic unit for determining a position on said image pickup surface on which a largest amount of reflected light from light illuminating said object in a specific direction is incident, said position being found by implementing a barycentric calculation based on samples (x) of the information output by said image pickup sensor and position coordinates (i) of reflected light incident on said light-receiving regions that falls within a predetermined vertical light-receiving range on the image pickup surface and with which said samples (x) correspond;
• and
• a second arithmetic unit for determining a position on a surface of said object that corresponds to each of said light-receiving regions, each position on the surface of said object being determined based on a relationship between said specific direction and a direction in which said reflected light is incident on said position determined by said first arithmetic unit.

A method of measuring a shape of an object, said method comprising:

• a projecting step of projecting a light onto the object and scanning the object with the light;
• a receiving step of receiving light reflected from the object with an image pickup sensor having a plurality of light-receiving regions across which the reflected light traverses according to the scanning of the object;
• a sampling step of periodically sampling information indicating an amount of the reflected light incident of on each of said light-receiving regions over time period;
• a storing step of storing into a memory the information which is periodically sampled over a predetermined time period for each of said light-receiving regions;
• a first determining step of determining a time when said reflected light traverses each of said light-receiving regions, each time being determined by implementing a barycentric calculation based on samples (x) of the information stored in the memory and an instant (i) at which each of said samples (x) is taken;
• and
• a second determining step of determining a position on a surface of said object that corresponds to each of said light-receiving regions, each position being determined based on a relationship between a direction in which said light illuminates said object at the time when said reflected light traverses the light-receiving region and a direction in which said reflected light is incident on the light-receiving region.

A method of measuring a shape of an object, said method comprising:

• a projecting step of projecting a light onto the object and scanning the object with the light;
• a receiving step of receiving light reflected from the object with an image pickup sensor having an image pickup surface including a plurality of light-receiving regions across which the reflected light traverses according to the scanning of the object;
• a sampling step of periodically sampling information indicating an amount of the reflected light incident on each of said light-receiving regions over time period;
• a storing step of storing into a memory the information which is periodically sampled for each of said light-receiving regions;
• a first determining step of determining a position on said image pickup surface on which a largest amount of reflected light from light illuminating said object in a specific direction is incident, said position being found by implementing a barycentric calculation based on samples (x) of the information stored in the memory and position coordinates (i) of reflected light incident on said light-receiving regions that falls within a predetermined vertical light-receiving range on the image pickup surface and with which said samples (x) correspond;
• and
• a second determining step of determining a position on a surface of said object that corresponds to each of said light-receiving regions, each position on the surface of said object being determined based on a relationship between said specific direction and a direction in which said reflected light is incident on said position determined in said first determining step.

A three-dimensional measuring apparatus for measuring a shape of an object, said three-dimensional measuring apparatus comprising:

• a scanner for emitting a light that illuminates the object, and scanning the object with the light;
• an image pickup sensor for receiving light reflected from the object, said image pick sensor having a plurality of light-receiving regions across which the reflected light traverses according to the scanning of the object;
• an image pickup controller for driving said image pickup sensor to sample information indicating an amount of the reflected light incident on each of said light-receiving regions at each of sampling instants over a scanning period;
• a first arithmetic unit for determining a time when said reflected light traverses each of said light-receiving regions, each time being determined by implementing a barycentric calculation based on samples (x) of the information output by said image pickup sensor taken at each of the sampling instants belonging to a prescribed period of time and an sampling instant (i) at which each of said samples (x) is taken;
• and
• an output unit for outputting information relating to said determined time for calculating a position on a surface of said object that corresponds to each light-receiving regions.

A three-dimensional measuring apparatus for measuring a shape of an object, said three-dimensional measuring apparatus comprising:

• a scanner for emitting a light that illuminates the object, and scanning the object with light;
• an image pickup sensor for receiving light reflected from the object, said image sensor having an image pickup surface including a plurality of light-receiving regions across which the reflected light traverses according to the scanning of the object;
• an image pickup controller for driving said image pickup sensor to sample information indicating an amount of the reflected light incident on each of said light-receiving regions at each of sampling instants over a scanning period;
• a first arithmetic unit for determining a position on said image pickup surface on which a largest amount of reflected light from light illuminating said object is incident for each of the sampling instants, each position being found by implementing a barycentric calculation based on samples (x) of the information output by said light-receiving regions belonging to said predetermined light-receiving range and position coordinates (i) of said light-receiving regions which takes said samples (x);
• and an output unit for outputting information relating to said determined position for calculating a position on the object surface.