Patent ID: 9739984
Date: 2017-08-22
CPC Classifications: B23K,G02B

Claim:
1. An Fθ lens for far-infrared laser processing, comprising a first lens, a second lens, and a third lens, which are coaxially arranged successively along a transmission direction of an incident light beam; wherein the first lens is a negative meniscus lens, the second and the third lens are positive meniscus lenses, middle portions of the first, the second and the third lens protrude toward the transmission direction of the incident light beam; wherein the first lens comprises a first surface and a second surface, the second lens comprises a third surface and a fourth surface, the third lens comprises a fifth surface and a sixth surface, the first surface to six surface are arranged along the transmission direction of the incident light beam; radiuses of curvature of the first surface to six surface are −50 mm, −60 mm, −68 mm, −50 mm, −500 mm, and −180 mm, respectively, and each has a tolerance of 5%.