| 摘要 |
A large filed achromatic lens is disclosed, including a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element arranged sequentially along the propagation direction of an incident ray. The first lens element is a meniscus lens element including a first curved surface and a second curved surface; the second lens element is a meniscus lens element, including a third curved surface and a fourth curved surface; the third lens element is a biconvex lens element, including a fifth curved surface and a sixth curved surface; the fourth lens element is a biconvex lens element, including a seventh curved surface and an eighth curved surface; the fifth lens element is a biconcave lens element including a ninth curved surface and a tenth curved surface; and the sixth lens element is a plane lens element adapted to play a role in protecting other lens elements. The first to the fifth lens elements are arranged around a same axis sequentially along the propagation direction of an incident ray. The first to the tenth curved surfaces are arranged sequentially along the propagation direction of the incident ray. The above large filed achromatic lens can be used as a fine photoetching lens for laser marking, or other fine processing lenses. |
| 主权项 |
1. A large filed achromatic lens, comprising:
a first lens element, which is a meniscus lens element, including a first curved surface and a second curved surface both protruding outward to an image side; a second lens element, which is a meniscus lens element, including a third curved surface and a fourth curved surface both protruding outward to an image side; a third lens element, which is a biconvex lens element, including a fifth curved surface protruding outward to an object side, and a sixth curved surface protruding outward to the image side; a fourth lens element, which is a biconvex lens element, including a seventh curved surface protruding outward to the object side, and an eighth curved surface protruding outward to the image side; a fifth lens element, which is a biconcave lens element, including a ninth curved surface protruding outward to the image side, and a tenth curved surface protruding outward to the object side; wherein the first to the fifth lens elements are arranged sequentially around a same axis along the propagation direction of an incident ray, and the first to the tenth curved surfaces are arranged sequentially along the propagation direction of the incident ray; wherein center thicknesses of the first to the fifth lens elements are 3 mm, 3 mm, 3 mm, 3 mm and 2 mm respectively, with an allowable tolerance of 10%, an upper variation of tolerance of +5%, and lower variation of tolerance of −5%; and wherein radiuses of curvature of the first to the tenth curved surfaces are −8 mm, −15 mm, −29 mm, −10 mm, 19 mm, −32 mm, 13 mm, −70 mm, −31 mm and 15 mm respectively, with an allowable tolerance of 10%, an upper variation of tolerance of +5%, and lower variation of tolerance of −5%. |
