| 摘要 |
PURPOSE:To eliminate the influence of a microwave by fitting a netting type member made of a good electric conductor to a window for detection formed in a shield case. CONSTITUTION:The infrared sensor is fitted while stored in a cylindrical socket part 16 provided to the front surface part of a shield box 15. An earth plate 17 made of copper, etc., is fitted to the front end surface of the cylindrical socket part 16 with screws. This earth plate 17 is provided contacting electrically the front surface part of the shield case 6 of the infrared sensor. Further, this earth plate 17 blocks completely the gap 18 between the shield case 6 of the infrared sensor and the cylindrical socket part 16 of the shield box 15. A hole 19 for detection is bored in the center part of the earth plate 17 at the position corresponding to the window 7 for detection of the infrared sensor. Consequently, the shield box 15, shield case 6 of the infrares sensor, and a netting type pattern 12 provided to an optical filter 11 are held at nearly the same potentials and a microwave entered from the gap 18 is cut off completely. |
