Patent ID: 8323434

Claim:
A method for manufacturing spherical Fresnel lens, comprising: providing a first optical element comprising a regular hexagonal first Fresnel micro-lens in the center of the first optical element and six regular hexagonal second Fresnel micro-lenses arrayed around the first Fresnel micro-lens, one edge of the second Fresnel micro-lens connected to one edge of the first Fresnel micro-lens; stressing the first optical element to yield a spherical cap configuration of the first optical element; providing a second optical element matched to the first optical element, the second optical element comprising a pentagonal third Fresnel micro-lens, three hexagonal fourth Fresnel micro-lens, and two heptagonal fifth Fresnel micro-lens, the third Fresnel micro-lens comprising a third edge, two fourth edges connected to the third edge of the third Fresnel micro-lens, and two fifth edges connected to the fourth edges of the third Fresnel micro-lens, the fourth Fresnel micro-lens comprising a sixth edge and a seventh edge opposite to the sixth edge of the fourth Fresnel micro-lens, the sixth edge of the fourth Fresnel micro-lens being connected to the third edge and the fourth edge of the third Fresnel micro-lens respectively, the fifth Fresnel micro-lens comprising a eighth edge, the eighth edge of the fifth Fresnel micro-lens being connected to the fifth edge of the third Fresnel micro-lens; bending the second optical element to yield a curve shaped configuration having a curvature as the bent first optical element; assembling a number of bent second optical elements around the bent first optical element in sequence by attaching the seventh edge of the fourth Fresnel micro-lens to the edge of the first optical element, to form a hemispherical-shaped configuration.