| 摘要 |
<P>PROBLEM TO BE SOLVED: To form a light-distribution pattern for a low-beam having horizontal and slanted cutoff lines at a top end section while enhancing utilization efficiency of its light source light flux in a direct-projection type lighting lamp tool for a vehicle using an approximately rectangular light-emitting surface as a light source. <P>SOLUTION: A lower end edge of the approximately rectangular light-emitting surface 12A is located at a horizontal line orthogonal to an optical axis Ax, and a point O on the lower end edge is arranged to locate on the optical axis Ax. Reflecting type Fresnel lenses are respectively formed on the back-side surface of a lens 14 while first and third lens ranges Z1, Z3 are formed with a primary datum line L1 as a reference and second and fourth lens ranges Z2, Z4 are formed with a secondary datum line L2 as a reference, and thereby the horizontal cutoff line can be formed. Furthermore, end zones on respective lens ranges Z1-Z4 are formed as extension zones Z1a-Z4a coming into their adjacent lens ranges at a designated angle, and thereby the slanted cutoff line can be formed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
