| 摘要 |
PURPOSE:To reduce the occurrence of a false lighting by giving the signal lamp device a structure in which the approximately 30% area of a lens from its upper side with the diameter of the opening of a reflection mirror as its reference is shielded with a light shielding member immediately before the lens. CONSTITUTION:A reflection mirror 1 has a curved surface composed of a paraboloid of revolution, an electric lamp 2 is provided for the position of the approximate focal point of the reflection mirror 1, and a lens 3, which is composed of red, yellow, or blue colored glass and has both surfaces having approximately the same radii of curvature, is provided for the edge part of the reflection mirror 1. Further, the traffic signal lamp device has the structure to satisfy a conditional expression 0.3<D/R<0.7 when the distance between the center of the opening of the traffic signal lamp device and the optical axis of the reflection mirror 1 is made into D, and the distance from the optical axis of the reflection mirror 1 to the edge part of the reflection mirror 1 is made into R when R is measured in a direction from the optical axis of the reflection mirror 1 to the center of the opening. Thus, the phenomenon of the false lighting in the traffic signal lamp device can be improved. |
