| 摘要 |
<p>A dart head (101), its wire grid (102) and electrically conductive beds (103) are of conventional diameter of 340 mm (13 3/8'), with a 60 mm non-scoring circumferential bed (104), giving an overall of 460 mm (18'). The dart head is arranged in a casing (115) at an aperture (116), with a 540 mm internal diameter, in a plastics foam block (117). A circular aerial (105) is buried in the foam 20 mm from the edge of the aperture (116). Thus the aerial has a diameter of 580 mm compared with the 340 mm overall diameter of the scoring beds (103) of the dart head. Transmitting and reception equipment and a microprocessor unit for detecting and scoring the position of a dart thrown at the dart head are provided.</p> |
