Patent ID: 8657705

Claim:
A golf ball having a large number of dimples, the golf ball having a fluctuation range Rh and a fluctuation range Ro each of which is 1.9 mm or less, the fluctuation range Rh and the fluctuation range Ro being obtained by the steps of: (1) assuming a line connecting both poles of the golf ball as a first rotation axis; (2) assuming a great circle which exists on a surface of a phantom sphere of the golf ball and is orthogonal to the first rotation axis; (3) assuming two small circles which exist on the surface of the phantom sphere of the golf ball, which are orthogonal to the first rotation axis, and of which an absolute value of a central angle with the great circle is 30°; (4) defining a region, of a surface of the golf ball, which is obtained by dividing the phantom sphere at the two small circles and which is sandwiched between the two small circles; (5) determining 30240 points, on the region, arranged at intervals of a central angle of 3° in a direction of the first rotation axis and at intervals of a central angle of 0.25° in a direction of rotation about the first rotation axis; (6) calculating a length L 1 of a perpendicular line which extends from each point to the first rotation axis; (7) calculating a total length L 2 by summing 21 lengths L 1 calculated based on 21 perpendicular lines arranged in the direction of the first rotation axis; (8) determining a maximum value and a minimum value among 1440 total lengths L 2 calculated along the direction of rotation about the first rotation axis, and calculating the fluctuation range Rh by subtracting the minimum value from the maximum value; (9) assuming a second rotation axis orthogonal to the first rotation axis assumed at the step (1); (10) assuming a great circle which exists on the surface of the phantom sphere of the golf ball and is orthogonal to the second rotation axis; (11) assuming two small circles which exist on the surface of the phantom sphere of the golf ball, which are orthogonal to the second rotation axis, and of which an absolute value of a central angle with the great circle is 30°; (12) defining a region, of the surface of the golf ball, which is obtained by dividing the phantom sphere at the two small circles and which is sandwiched between the two small circles; (13) determining 30240 points, on the region, arranged at intervals of a central angle of 3° in a direction of the second rotation axis and at intervals of a central angle of 0.25° in a direction of rotation about the second rotation axis; (14) calculating a length L 1 of a perpendicular line which extends from each point to the second rotation axis; (15) calculating a total length L 2 by summing 21 lengths L 1 calculated based on 21 perpendicular lines arranged in the direction of the second rotation axis; and (16) determining a maximum value and a minimum value among 1440 total lengths L 2 calculated along the direction of rotation about the second rotation axis, and calculating the fluctuation range Ro by subtracting the minimum value from the maximum value.