| 摘要 |
In a vehicular lamp, a reflecting surface formed on the inner surface of a lamp body is divided into three reflecting regions in a horizontal direction, the reflecting surface having a left side wall that extends in a front-to-rear direction. The reflecting region in the middle has a shape so as to form a part of an ellipsoid of revolution whose axis of revolution coincides with the principal optical axis of the reflecting surface. A lamp bulb is located in the vicinity of a focal point of the ellipsoid of revolution. The shape of each of the reflecting regions is such as to be a part of an envelope of a group of paraboloids of revolution, the horizontal section of the envelope being expressed by an equation of a curve, y2=4fx+axn, where f is a focal distance, and a and n are constants with a>0 and n>1, when a reference axis thereof is set as an x-axis and an axis orthogonal to the x-axis is set as a y-axis in a horizontal plane, such paraboloid of revolution also having an axis thereof in the same plane as the horizontal section, sharing a focal point in common with the curve, and being in contact with the curve at a point on the curve. The reference axes of the reflecting regions are inclined with respect to the axis of revolution of the reflecting region at predetermined respective angles.
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