Aspherical LED angular lens for central distribution patterns and LED assembly using the same

An aspherical LED angular lens for central distribution patterns, applied in an LED assembly, and having an LED die, a seal gel and an optical lens arranged along a central axis from a source side to an project side, in which:

• the optical lens is a lens having a concave surface and a convex surface, and the concave surface is an optical surface facing the source side of the LED die, and the convex surface is an optical surface facing the project side of the LED die, and at least one of the optical surfaces is aspherical;
• and the optical lens satisfies the condition of:
• 0.7
• ≤
• 
• R
• 1
• -
• R
• 2
• R
• 1
• +
• R
• 2
• 
• ≤
• 1.0
• where, R1 is the radius of curvature of the optical lens at the optical surface of the source side, and R2 is the radius of curvature of the optical lens at the optical surface of the project side, and wherein the optical lens satisfies the condition of:
• 0.2
• ≤
• (
• N
• d
• ⁢
• ⁢
• 2
• -
• 1
• )
• ⁢
• d
• 2
• f
• s
• ≤
• 0.4
• where, fs is the effective focal length of the optical lens, d2 is the thickness of the optical lens on the central axis, and Nd2 is the refractive index of the optical lens.