| 摘要 |
PROBLEM TO BE SOLVED: To improve infrared ray directivity at a light projection side, and to improve the light receiving sensitivity of an infrared ray at a light reception side, and to simplify the high precision and miniaturization of the device. SOLUTION: This crime prevention sensing device is provided with a light projection/reception integral type detection unit 1 for incorporating a light projecting element 4 and a light receiving element 8. The light projecting element 4 is arranged so as to be faced to an opposite direction E1 to an infrared ray projecting direction E, and the light receiving element 8 is arranged so as to be faced to an opposite direction F1 to an infrared ray receiving direction F. A light projection side concave reflector 9 for reflecting an infrared ray A to be emitted from the light projecting element 4 to the infrared ray projecting direction E as a parallel beam and a light reception side concave reflector 13 for reflecting the infrared ray A from an infrared ray receiving direction F to the light receiving element 8, and for collecting the focal point of reflection to the light receiving element 8 are arranged between the light projecting element 4 and the light receiving element 8. COPYRIGHT: (C)2006,JPO&NCIPI |
