Workpiece processing device and method

A workpiece processing device for processing a workpiece having a central axis and having a cylindrical-shape surface, comprising:

• a workpiece supporting unit rotatable about a first axis thereof, and configured to support the workpiece so that the workpiece is rotatable around the first axis, and the workpiece supporting unit is configured to accommodate the workpiece in an orientation where the central axis of the workpiece and the first axis are parallel to each other and in an orientation where the central axis of the workpiece and the first axis deviate from each other;
• a cutting unit having a blade configured to cut a surface of the workpiece supported by the workpiece supporting unit;
• a detecting unit configured to calculate a position of a vertex of the surface of the workpiece in a direction along a second axis which is perpendicular to the first axis and parallel to a cutting plane of the blade;
• and
• a control unit configured to control the workpiece supporting unit so that a cutting position on the surface of the workpiece is located at the vertex, and relatively move the workpiece supporting unit and the cutting unit so that the cutting plane of the blade is on a plane defined by the central axis of the workpiece and the cutting position on the surface of the workpiece to form a groove at the cutting position.