| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball for a ball game which is advantageous in accurately and precisely measuring a moving speed and trajectory by a measuring device even if the radio wave output from the measuring device is weak or the receiving sensitivity of the measuring device is low. <P>SOLUTION: The ball 2 for baseball includes a ball body 20 and a reflection layer 22. The ball body 20 is formed by a spherical and three-dimensional core layer 24 and a cover layer 26 covering the core layer 24. The core layer 24 is formed from a spherical and three-dimensional inner core layer 2402 and an outer core layer 2404 covering the inner core layer 2402. The reflection layer 22 has the radio reflection property, and is formed all over the spherical surface around the center of the ball body 20. The reflection layer 22 is formed all over the region on the inner surface of the cover layer 26, which is, all over the region on the outer surface of the outer core layer 2404. The reflection layer 22 efficiently reflects radio waves (microwaves). <P>COPYRIGHT: (C)2011,JPO&INPIT |
