| 摘要 |
<p>PURPOSE:To provide a compact infrared ray detector, in which the generation of noise is reduced. CONSTITUTION:An infrared ray shielding plate 12 for shielding the infrared ray to an infrared ray detecting element 16 is provided freely to be slide with guide by a guide part 17. A permanent magnet 13 is connected to the infrared ray shielding late 12, and the top surface side 3 of the permanent magnet 13 is formed into the S pole, and the bottom surface side 4 is formed into the N pole. A fixed magnet 14, of which bottom surface side is formed into the S pole, is arranged opposite to the top surface side 3 of the permanent magnet 13 through a space, and an electromagnet 15 is arranged opposite to the bottom surface side 4 of the permanent magnet 13 through a space. Current is applied to the electromagnet 15 by a chopper driving unit 22 so that the top surface side of the electromagnet 15 is formed into the N pole, and quantity of this applying current is changed so as to change the largeness of the reacting magnetic force of the electromagnet 15 and the permanent magnet 13, and the infrared ray shielding plate 12 is thereby slid for movement in the vertical direction.</p> |
