Workpiece position determination device, laser machining device, and workpiece position determination method
A workpiece position determination device includes an imager, a driver to move the imager relative to a workpiece in a planar direction parallel to a planar surface of the imager, a controller to control the driver so that the imager moves along a prescribed trajectory that passes through locations in a boundary portion in the planar surface in a plan view, a storage to store image information captured by the imager while the imager moves along the prescribed trajectory, and coordinate information of the imager at a time of capturing each image information, a position determiner to determine the position of the workpiece in the planar direction corresponding to the boundary portion based on the image information and the coordinate information stored in the storage, and an offset determiner to determine an offset of the workpiece from a reference position based on a determination result from the position determiner.
1 . A workpiece position determination device comprising:
an imager;
a driver to cause the imager to move relative to a workpiece including a planar surface, in a planar direction parallel or substantially parallel to the planar surface;
a controller configured or programmed to control the driver so that the imager moves along a prescribed trajectory that passes through a plurality of locations in a boundary portion in the planar surface in a plan view; and
a storage to store image information captured by the imager while the imager moves along the prescribed trajectory, and coordinate information of the imager at a time of capturing each image information; wherein
the controller is configured or programmed to define and function as:
a position determiner to determine the position of the workpiece in the planar direction corresponding to the boundary portion, based on the image information and the coordinate information stored in the storage; and
an offset determiner to determine an offset of the workpiece from a reference position, based on a determination result from the position determiner.
2 . The workpiece position determination device according to claim 1 , wherein an imaging optical system in the imager is coaxial with a laser beam irradiation optical system in a machining unit of a laser machining device that machines the workpiece by irradiating the workpiece with a laser beam.
3 . The workpiece position determination device according to claim 1 , wherein
the controller is configured or programmed to control the driver so that the imager captures an image of a reference hole in the workpiece while moving along a prescribed trajectory that passes through a plurality of locations on an inner peripheral edge of the reference hole in a plan view; and
the position determiner is operable to calculate a position of a center of the reference hole in the workpiece.
4 . The workpiece position determination device according to claim 3 , wherein the controller is configured or programmed to control the driver so that the imager moves along a trajectory that defines a prescribed point-symmetric shape or line-symmetric shape in a plan view.
5 . The workpiece position determination device according to claim 3 , wherein an observation range of one image captured by the imager is smaller than the reference hole.
6 . The workpiece position determination device according to claim 1 , wherein
the controller is configured or programmed to control the driver so that the imager captures an image of an end portion corresponding to a side of the workpiece while moving along a prescribed trajectory that passes through a plurality of locations on the end portion in a plan view; and
the position determiner is operable to calculate a position of the end portion on the workpiece.
7 . The workpiece position determination device according to claim 6 , wherein the controller is configured or programmed to control the driver so that the imager moves along a trajectory that defines a prescribed linear shape, a curved shape, a zigzag shape, or a spiral shape in a plan view.
8 . The workpiece position determination device according to claim 1 , wherein the position determiner is operable to select, among a plurality of pieces of the image information captured by the imager, the image information used to determine a position of the boundary portion, and determine the position of the boundary portion, based on the coordinate information corresponding to the image information selected.
9 . The workpiece position determination device according to claim 1 , wherein the offset determiner is operable to determine, from a result of determining a position of at least one of the boundary portions, a shift amount relative to the reference position in each of a first direction and a second direction orthogonal to each other.
10 . The workpiece position determination device according to claim 9 , wherein the offset determiner is operable to determine, from results of determining positions of at least three of the boundary portions, a shift amount relative to the reference position in each of a first direction and a second direction orthogonal to each other, and a rotation amount around an axis of a third direction orthogonal to the first direction and the second direction.
11 . A laser machining device comprising the workpiece position determination device according to claim 1 , the laser machining device including a machining unit to irradiate a workpiece including a planar surface with a laser beam to machine the workpiece.
12 . A workpiece position determination method comprising:
causing an imager to move relative to a workpiece including a planar surface, in a planar direction parallel or substantially parallel to the planar surface and along a prescribed trajectory that passes through a plurality of locations in a boundary portion in the planar surface in a plan view;
storing image information captured by the imager while the imager moves along the prescribed trajectory, and coordinates information of the imager at a time of capturing each image information;
determining the position of the workpiece in the planar direction corresponding to the boundary portion, based on the image information and the coordinates information stored in the storage; and
determining an offset of the workpiece from a reference position, based on a result of determining the position corresponding to the boundary portion.