Patent ID: 8462195

Claim:
A panoramic imaging lens comprising: an annular incident surface symmetrically formed around a light axis of the panoramic imaging lens; a circular bottom surface symmetrically formed about the light axis and comprising: a light outgoing portion formed in convex form at a central part of the circular bottom surface; and an annular reflective portion formed in a concave form and connecting between a periphery of the light outgoing portion and the annular incident surface to total reflect the light from the annular incident surface; and a circular upper surface symmetrically formed about the light axis and comprising: a circular reflective portion formed in a concave form at a central part of the circular upper surface to reflect the light from the annular reflective portion toward the light outgoing portion; and an annular connecting portion formed in a flat form connecting between a periphery of the circular reflective portion and the annular light incident surface, an incident point on the annular incident surface and a reflection point on the annular reflective portion of the same light satisfies the relation: α+β>θ, wherein α is a refraction angle of the light at the refraction point, β is an angle between a first tangent plane comprising the refraction point and a second tangent plane comprising the reflection point, θ is the critical angle of the total reflection between the panoramic imaging lens and the air, and wherein a surface of the annular reflective portion is an aspherical surface, and the aspherical surface is shaped according to a formula: x = ch 2 1 + 1 - ( k + 1 ) ⁢ c 2 ⁢ h 2 + ∑ Aih i , where h is a height from the optical axis of the panoramic imaging lens to the aspherical surface, c is a vertex curvature, k is a conic constant, and Ai are i-th order correction coefficients of the aspherical surface.