| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a distance detecting apparatus capable of detecting stains on the surface of a sensor. <P>SOLUTION: First and second light receiving elements 10 and 11 are opposed to a projection window part 1c and an incident window part 1d. DC light incident from them are received by the first and second light receiving elements 10 and 11. On the basis of an output ratio between the first and second light receiving elements 10 and 11, for example a ratio between their output voltages, it is possible to detect stains. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
