PURPOSE: To inform a player of head-up immediately after an impact by using impact sound produced when a club-head hits a ball as a decision timing element, and by obtaining a decision signal by differentiation of the output of an operation sensor, thereby detecting the movement of its head.
CONSTITUTION: When a microphone 1 catches impact sound, a damped waveform is produced via a band pass filter 3, and a waveform compared with the threshold of a comparator 5 appears as a waveform B. The waveform B appears via a delay circuit 11 only one pulse as a waveform C after delay. On the other hand, the output of an operation sensor 2 is rectified by means of a rectifier circuit 7, the rectified output is differentiated by means of a differentiation circuit 8 to appear as a waveform D, and a waveform E is obtained by comparing the waveform D with the threshold of the comparator 10. When a waveform as the decided output of the operation sensor 2 exists during the appearance of the waveform C as delay timing, an AND gate 12 decides that head-up has occurred, and drives an output circuit 14.
IWATANI TOSHIHIKO
YAMAGUCHI TAKUMI
