1989 年 45 巻 2 号 p. 74-83
The geometrical patterns formed by superposing the two figures of dots arranged at points of intersection of rectangle fretwork have been investigated by using a personal computer. Rotating a dot plane (B-plane) to another fixed dot plane (A-plane), the rotation cycle at which the same patterns are formed is 180°, and the symmetric point is found at 90°. When the l2/l1-value is smaller than tan θ, the revealed patterns form rectangles which consist of dot chains surrounding overlapped dots, and the ratio of long to short side of the patterns is the same as that of dot pitchs, where θ is the rotation angle of B-plane to A-plane, l1 and l2 are the dot pitch of breadth and length, respectively. When the l2/l1-value is larger than tan θ, the patterns result in the drastic change which is not found in the case of the same two figures of dots arranged at points of intersection of square fretwork. These patterns will be expected to be practical as printing patterns for cloth etc.