OBJECT-DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To detect a lane marker and other obstacles (preceding vehicles) being provided on a road with a simple configuration. SOLUTION: A transmission antenna 10 and a reception antenna 12 are provided, and a polarizer 14 and a polarizer 15 are provided. The polarization direction of the polarizer 14 and the polarizer 15 can be changed by a motor 16. Linear polarization at 45 deg. from the transmission antenna 10 is converted to circular polarization by the polarizer 14 and is applied to an object. A lane marker reflects an incidence electronic wave for two times for reflecting as the same turning circular polarization, and a preceding vehicle reflects an incidence electronic wave once for reflecting as inverse turning circular polarization. The polarizer 15 converts the turning circular polarization to 45 deg. linear polarization at a certain timing and converts the inverse turning circular polarization to 45 deg. linear polarization at another timing. An identification device 1 can distinguish the lane marker from the preceding vehicle according to the intensity of the reception antenna 12.