| 摘要 |
<P>PROBLEM TO BE SOLVED: To reliably detect a ball that has been hit to a foul region near a foul pole and display that the ball is a foul. <P>SOLUTION: That a ball has been hit to the foul region near the foul pole 7 is detected by means of a beam sensor 2 that emits and receives a plurality of optical beams that is installed in the foul region adjacent to the foul pole 7 set up at a site that a foul line of a baseball field is in contact with a fence 24, and that the ball is a foul is displayed on a confirmation display device 4. Thereby, it is correctly and easily checked whether the ball that has been hit near the foul pole 7 is fair or foul. <P>COPYRIGHT: (C)2012,JPO&INPIT |
