| 摘要 |
PROBLEM TO BE SOLVED: To reduce the influence of sunlight in detecting contamination of a lens of a lighting device or a camera.SOLUTION: When the area of a marker image is beyond a set range, or significantly changes, a fault flag 1 is set (S53). When the shape of the marker image is deformed significantly, a fault flag 2 is set (S56). A value for defining the area or the shape of the marker image is hardly influenced by sunlight. When contamination is detected, the influence of sunlight can be reduced by use of the value for defining the area or the shape of the marker image, thereby improving accuracy of detecting contamination. |
