IMAGE PROCESSING METHOD OF SQUARE PART

PROBLEM TO BE SOLVED: To enable highly accurate angle detection by picking up a square part by a camera in a state that the one side of the outside shape of the square part is inclined with respect to the array of the light receiving elements of the camera and recognizing the angle of rotation of the outside shape by images. SOLUTION: While a square part 10 is in a state that the y-axis of a camera and the one side L of the square part 10 are nearly in parallel with each other such as a straight line (3), the angle of rotation of the square part 10 is not directly detected. In this case, a suction nozzle is accurately rotated by 45 degrees by the rotation driving means of a placing head so that the y-axis of the camera may form an angle of approximately 45 degrees with the side L of the square part 10. The image of the square part 10 in this state is picked up, and the angle of the outside shape is detected by image recognition. In the case that the initial displacement in the angle of the square part 10 is, for example. 8 degrees (regularly < 1 degree), the amount of rotation of 45 degrees is added, and the angle of the outside shape is detected as θ+45 degrees. Then, by correcting the angle of rotation of the square part 10 to exact 45 degrees (a rotation of -θ degrees) on the basis of the angle detection and further returning it to a former angle by 45 degrees (a fixed amount of rotation of -45 degrees), the angle which the side L of the square part 10 forms with the y-axis of the camera is corrected to zero degree at which the side L of the square part 10 is perfectly in parallel with the Y-axis.