Patent ID: 7382543

Claim:
A method for manufacturing a fθ lens with multi-section optical surfaces and with a continuing surface profile by injection molding comprising the steps of: defining and fixing a plurality of optical sections having a plurality of optical surfaces and wherein each of the optical surfaces in each section consists of a specific coefficient set and wherein said fθ lens includes between 2 and n optical sections; obtaining the best specific coefficient set for each separate optical surface of each section through optical simulation and then forming the topical surface for each section to form a curve fall on two borders of two adjacent applied surfaces; amending a curve fall by using curve fitting simulation and/or optical simulation wherein the curve fitting simulation is by applying two specific coefficient sets of said two borders to define a continuing surface profile on the two borders and the optical simulation is by applying two specific coefficient sets of two borders to define a continuing surface profile on said two borders and then forming the topical surface for each section; using the specific coefficient sets and said best continuing surface profile to produce a mold for injection molding; manufacturing the fθ lens with continuing surface profile by using a mold; and wherein the mold for injection molding is produced by super-precise NC machining to enact the SAG for machine processing, and wherein the SAG is controlled by all data of the optical surface and the continuing surface profile.