Patent ID: 6419381
Filing Date: 2002-07-16
Classification: F21S,F21V

Abstract:
A vehicle head lamp comprising:a light source body; and a reflecting mirror having areas of a reflecting face defined by: (a) a reference curve which, for various reflecting face portions, is either set in a horizontal reference plane containing an optical axis, or set in a slant reference plane inclined at a predetermined angle with respect to the horizontal reference face and using the optical axis as an axis of rotation; (b) said light source body, having a center axis extending along the optical axis, placed in the proximity of a reference point of the reference curve; and (c) a reflecting face formed as a set of cross lines provided by cutting a virtual paraboloid of revolution having an axis parallel with a light beam vector of reflected light when light assumed to be emitted from the reference point of the reference curve positioned on the optical axis is reflected at an arbitrary point on the reference curve, wherein the paraboloid passes through the reflection point, and has the reference point as a focus, and wherein said paraboloid of revolution is cut on a virtual plane containing the light beam vector and parallel with a plane orthogonal with or inclined to either the horizontal reference or the slant reference plane; wherein the basic face provides a light distribution pattern of a downward beam having a slant cutoff line inclined with respect to a horizontal line, further wherein for a reflecting-face first reflecting area, close to the horizontal reference plane when the reflecting face is viewed from the optical axis direction, a reference curve is set in a slant reference plane inclined to the horizontal reference plane at a first angle equal to an angle of the slant cutoff line with the horizontal line, and further wherein for a reflecting-face second reflecting area, positioned above or below the first reflecting area with respect to the horizontal reference plane when the reflecting face is viewed from the optical axis direction, a second reference curve is set in a second slant reference plane inclined to the horizontal reference plane at a second angle larger than 0Â° and smaller than the angle of the slant cutoff line with the horizontal line.