| 摘要 |
A reflective surface 10a of a reflector 1 in a vehicle lamp is formed in such a way that a free-formed surface 20 is created as a basic shape so as to satisfy a light uniformity condition and shape constraints. Initial reference lines 22<SB>1</SB> to 22<SB>8</SB> extend radially from light source 11 on optical axis Ax and such that the initial luminous exitance at any point along the line is a constant value (figure 4), the initial reference lines are then deformed to form surface reference lines which satisfy the shape constraints whilst maintaining the uniform light condition that the maximum luminous exitance is no more than 6 times the minimum. Once the surface reference lines have been determined the reflective surface is determined by dividing the free-formed surface into an array of segments each of which is assigned a reflective surface element (14, Fig 10) having a diffuse reflective region (16, Fig 10). |
