Patent ID: 8287780
Filing Date: 2012-10-16
Classification: B29C,B29D,B29L,G02B

Abstract:
1. A method for manufacturing a Fresnel lens, comprising the following steps: a. providing a mixture for forming a Fresnel lens; b. providing a lower mold on which the mixture is disposed; c. vacuumizing the mixture on the lower mold in a sealed cabinet by pumping air from the sealed cabinet, wherein the mixture is repeatedly vacuumized 5 or 6 times, and for each time of vacuumization the mixture is kept in vacuum condition for 20 seconds by pumping air from the sealed cabinet for 20 seconds: d. heating the mixture at a temperature of 35 degrees Celsius for 1 minute and then providing an upper mold to exert a pressure on a top surface of the mixture toward the lower mold; e. vacuumizing the mixture on the lower mold again; and f. heating the mixture on the lower mold to harden the mixture whereby the Fresnel lens is obtained.