| 摘要 |
<p>PURPOSE:To prevent very fine contaminants from occurring due to the sliding action of the lid of a case so as to keep the surrounding of the case clean by a method wherein the case, the lid, and a lid closing-opening mechanism are provided, and the lid of the case is opened or closed by a magnetic force. CONSTITUTION:When a case 3 is closed by a lid 2, a magnet contained in an attraction means 1 of the lid 2 attracts a magnetic substance 4 provided to the peripheral part of the opening of the case 3 by a magnetic force to enable the lid 2 to be attracted to the case 3 to cover an opening 14. When the lid 2 is dismounted to make the case 3 open, a lid opening-closing means 7 is made to cover the lid 2 so as to fit the attraction means 1 into a coil 9, and a current is made to flow through the coil 9 so as to cancel the magnetic field of the attraction means 1. On the other hand, a current is made to flow through an electromagnet 8 of the lid opening-closing means 7 to excite to enable the electromagnet 8 to attract a magnetic substance 6 of the lid 2. The lid opening-closing means 7 is separated from the case 3 to dismount the lid 2 from the opening 14 of the case 3 to make the case 3 open. By this setup, very fine contaminants can be prevented from occurring due to the sliding action of the lid of a case, so that the surrounding of the case can be kept clean.</p> |
