| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance identification accuracy between reflection light and disturbance light from a raindrop or the like attached to a windshield. <P>SOLUTION: Light is radiated from a light source to a windshield, an image sensor receives reflection light reflected on a raindrop attached to the windshield, a raindrop images are successively imaged in a prescribed imaging frequency, a light source for radiating light that becomes strong and weak in a drive frequency different from the imaging frequency is used as the light source when detecting a raindrop on the basis of the imaged image, the image sensor receives the reflection light through an optical filter for selecting the reflection light and making the reflection light transmit, a beat on an image caused by a difference between the imaging frequency and the drive frequency is detected, and an image area where the beat is detected is discriminated as an image area with an attachment reflected. <P>COPYRIGHT: (C)2013,JPO&INPIT |
