| 摘要 |
PURPOSE:To enable inexpensive detection of a distance by using a lamp device for a vehicle with a photo detecting means to detect a photo detecting position in the direction of a gap of a slit and a distance detection means to detect the distance to an object from the photo detecting position. CONSTITUTION:Light radiated with a high mount stop lamp 14 is reflected on a vehicle 20 running behind. The reflected light of the light is detected with a photo detecting lens 4 having slit 15 in the perimeter thereof to be incident into a position detector 2. When the light enters the position detector 2, a position at which the light is incident is detected according to a value of a photocurrent to be generated within a semiconductor substrate. A slit 15 is set to limit light to be incident into the lens 4 so that the light other than that from a specified direction is not incident into the lens 4. The light admitted into a position detector 2 through the lens 4 is converted into an electrical signal and inputted into a distance detection circuit 3 thereby calculating a vehicle-to- vehicle distance from the vehicle 20. |
