| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect an object in a monitoring area even in the case where monitoring areas widely spread from the vicinity of a laser radar to a long distance. <P>SOLUTION: In a monitoring area where a distance from a laser radar head 5 in the main scanning direction X of scanning light LB1 is long, the degree of diffusion of reflected light LB2 is high, the intensity of the reflected light LB2 decreases. Therefore, in a monitoring area where a distance from the laser radar head 5 in the main scanning direction X is long, the pulse signal period of a driver circuit 1a of a laser projector 1 is lengthened. Consequently, the period for which exciting atoms are accumulated in an optical fiber 1d of an optical fiber amplifier 1b is lengthened. As a result, initial small light is made incident on from a laser diode 1c, thereby exciting the electron of the core of the optical fiber 1d, and increasing accumulated exciting energy and hence the gain of the amplitude of the initial small light and the intensity of laser beam LB output from the optical fiber 1d. As a result, the intensity of the scanning light LB1 increases and, so does the intensity of the reflected light LB2. <P>COPYRIGHT: (C)2012,JPO&INPIT |
