Illuminating lens design method and illuminating lens

An illuminating lens system, comprising:

• an illuminating lens, comprising an inner cavity surface with a downward opening and an outer surface;
• a lens holder provided at the bottom of the illuminating lens, wherein the lens holder is provided with a through hole communicating with the inner cavity surface, and the through hole is in smooth transition with the inner cavity surface;
• and
• a plurality of support legs provided at the bottom of the lens holder;
• wherein projections of the highest points of the outer surface and the inner cavity surface of the illuminating lens on the horizontal plane are overlapped, and in a rectangular coordinate system, a horizontal profile curve of the outer surface and the inner cavity surface of the illuminating lens obtained from arbitrary height satisfies the following equation:
• (
• |
• x
• i
• |
• a
• i
• )
• n
• i
• +
• (
• |
• y
• i
• |
• b
• i
• )
• n
• i
• =
• 1
• where ai is the projection length of a portion of an xz section basic profile curve, which is intercepted by an xiyi plane, on the xiyi plane;
• bi is the projection length of a portion of a yz basic profile curve, which is intercepted by the xiyi plane, on the xiyi plane;
• xi, yi are coordinates of certain point on the outer horizontal profile curve and the inner horizontal profile curve;
• ni is a real number greater than 1.