| 摘要 |
PROBLEM TO BE SOLVED: To provide a security device which includes a rotary mirror rotated by a motor, emits laser light for scanning from the rotary mirror, and detects a direction where a reflection object is present and a distance to the reflection object by receiving reflection light of the emitted laser light, wherein, upon receiving laser light, the security device discriminates whether or not the received laser light is the laser light emitted from other security device.SOLUTION: In a plurality of times of rotations of a rotary mirror 11, when the security device continuously receives reflection laser light at a same rotation angle position, if there are changes in time periods from emission to reception of the laser light of the reflection laser light having received the plurality of times and there is no change in the reception light intensity of the reflection laser light, the security device determines that the received laser light is not emitted by itself but emitted from another security device. |
