| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce a widened drive beam by defining the angular extents of diopter lens so that the diopter lenses are interposed between a light source and one lateral zone of a reflector. SOLUTION: This headlamp for automobiles includes a light source 10, a reflector 20 whose focal point is located at or near the light source 10, a cover glass, and two displaceable diopter lenses 40a, 40b. The diopter lenses are adapted to be selectively interposable between the light source 10 and a predetermined zone of the reflector 20. The lenses 40a, 40b have inner surfaces 41a, 41b, each having the shape of a portion of a rotating cylinder with its center located approximately at the optical axis A of the headlamp with which a filament 10 is aligned. The angular extents of the lenses 40a, 40b are defined so that the lenses 40a, 40b are interposed between the light source 10 and one lateral zone of the reflector 20.</p> |
