| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a device cannot be downsized.SOLUTION: A water droplet detector includes: a light emitting member 10 that almost vertically enters pulse light into a reflection member 11 provided on the internal surface of glass 2; a standard light receiving member 20 that receives pulse light almost vertically reflected from the reflection member 11; a detection light receiving member 30 that receives pulse light that almost vertically enters into the glass 2 and is almost vertically reflected from the glass 2 by the light emitting member 10; and a phase comparison part 60 that compares the phase of an output signal of the standard light receiving member 20 and the detection light receiving member 30. The presence or absence of water droplets on the internal surface or external surface of the glass 2 is detected by the output signal of the phase comparison part 60. |
