Piezoelectric strip based sports ball localisation device - has two metallic electrodes connected to electronic circuit which analyses and discriminates pulses produced by impact of ball on ground

摘要

The device localises the falling point of a ball or other sports object on the ground in games such as tennis and squash. A transductor is formed on the ground along the limits of the game by at least one fluoride or polyfluoride of vinylidene. The film lies between two metallic electrodes which are realised by deposition of a metallisation layer on the two faces of the film or by two metal strips such as aluminium sheets. The piezoelectric strip has a shield in the form of a metallic envelope insulated from the electrodes and connected to one of the ends of one of the electrodes. A plastic protecting sheath surrounds the assembly. The two electrodes are connected to an electronic appts. which detects and analyses pulses arising from impact on the strip. The output from the electronic appts. is amplified to give a visual or audio indication of a pulse.