| 摘要 |
PROBLEM TO BE SOLVED: To surely recognize a monitor and to calculate a distance of a succeeding vehicle with high accuracy even on the occurrence of unclear visibility due to water drops or mist or the like at a twilight time and of a change in a vehicle velocity by controlling an optical characteristic of an image pickup means based on an optical characteristic control command signal where a surrounding environment and a drive state are taken into account. SOLUTION: A surrounding environment detection section 3 captures a lightness signal from a CCD camera 1 and generates three signals; a day time signal, a twilight time signal, and a night signal depending on the lightness level. On the other hand, a drive state detection section 4 detects a forward and backward drive state of a vehicle on the basis of an A/T shift position signal and two speed states; a low speed and a high speed on the basis of a vehicle velocity signal, and transmits them to an optical characteristic control generating section 5 respectively. Then the optical characteristic control mode of the CCD camera 1 is set by combining respective input signals to the surrounding environment detection section 3 and the drive state detection section 4. For example, the aperture adjustment and the image pickup output signal luminance level adjustment for the day time and the night are conducted independently of the presence of on/off of a light signal and a wiper signal for the daytime and at night.
|
