| 摘要 |
<p>A miner's cap lamp includes a reflector (11) having a substantially parabolic reflecting surface having a lamp reflector having a substantially parabolic reflecting surface wherein the curvature of the reflecting surface has a gradient variation from that of a true parabola curve Y<2> = 4MX along at least one line towards the outer edge (14) of the reflector, wherein the gradient along said line has a value equal to that of a true parabola at the maximum value of X for the reflector but has a value greater than the gradient of a parabolic surface for a modified region (19,20) located nearer the pole of the curve, the said gradient variation varying continuously over said modified region, such that the said gradient variation is a minimum at the maximum value of X of the modified region and the said gradient variation is a maximum at the minimum value of X of the modified region.</p> |
