| 摘要 |
<p>PURPOSE: To change a detecting range in an instant by providing a scanning change control means for changing the scan range of plural infrared detecting elements scanned by a scanning means according to the vehicle speed detected by a vehicle speed detecting means. CONSTITUTION: In the case of low speed travel being judged by a vehicle speed judging part 107, a scanning change control part 108 sets a scan range, scanned by a scanning part 103, to the horizontal element number M=0-511 and vertical element number N=0-511 of infrared detecting elements 201 (all the elements of plural infrared detecting elements 201). In the case of high speed travel being judged by the vehicle speed judging part 107, the scanning change control part 108 sets the scan range, scanned by the scanning part 103, to N=0-511 which is the whole area to the vertical element number N of the infrared detecting elements 201 and to the elements up to the 256th row, up to M=128--383 to the horizontal element number M, that is, the half of the scan range at the low speed travel time. The scan range of an infrared detecting part 102 scanned by the scanning part 103 is thereby changed.</p> |
