| 摘要 |
PURPOSE:To keep a chromatic fringe due to chromatic aberration quiet in a flux distribution pattern, and provide the horizontal expansion of the pattern by making variable the focal distance of a projector lens constituting a projector type headlamp. CONSTITUTION:A projector type headlamp condenses reflected light from reflecting surface to the vicinity of the upper end of a douser 5 laid in the vicinity of the second focal point of the reflecting surface, and projects the light through a projector lens 8 after determining a pattern image corresponding to a cut line. Furthermore, the lens is so designed that a focal point comes to be positioned at the upper front end of the douser 5 over a range A within the specified distance of an optical axis, when the projector lens 8 is viewed from the front, and a rear focal distance becomes longer toward the peripheral end of the lens in a range B outside the range A. In addition, the design is so made that the variation (DELTABfx-z) of a rear focal distance for a lens portion belonging to the range B with the projector lens 8 cut along a horizontal plane including the optical axis, becomes larger than the variation (DELTABfy-z) of a rear focal distance for a lens portion belonging to the range B with the lens 8 cut along a vertical plane including the optical axis. |
