| 发明名称 | Projection lens | ||
| 摘要 | A projection lens, in order along an optical axis from an image formation side to an image source side, includes a first lens, an aperture, a second lens, a third lens, and a fourth lens. The first lens is a meniscus lens with positive refractive power and a convex surface thereof facing the image formation side, and has at least an aspheric surface. The second lens is a biconcave lens with negative refractive power, and has at least an aspheric surface. The third lens is a biconvex lens with positive refractive power, and the fourth lens is a biconvex lens with positive refractive power, and has at least an aspheric surface. Therefore, the projection lens has a small size and high zoom ratio. | ||
| 申请公布号 | US8953259(B2) | 申请公布日期 | 2015.02.10 |
| 申请号 | US201213615332 | 申请日期 | 2012.09.13 |
| 申请人 | Asia Optical International Ltd. | 发明人 | Hsiung Chien-Chih;Huang Yu-Hsiang;Lin Yun-Yi |
| 分类号 | G02B9/00;G02B9/34 | 主分类号 | G02B9/00 |
| 代理机构 | Apex Juris, PLLC | 代理人 | Heims Tracy M.;Apex Juris, PLLC |
| 主权项 | 1. A projection lens, in order along an optical axis from an image formation side to an image source side, comprising: a first lens, which is a meniscus lens with positive refractive power and a convex surface thereof facing the image formation side, having at least an aspheric surface; an aperture; a second lens, which is a biconcave lens with negative refractive power, having at least an aspheric surface; a third lens, which is a biconvex lens with positive refractive power; and a fourth lens, which is a biconvex lens with positive refractive power, having at least an aspheric surface; wherein the fourth lens has a condition of 9 mm<f4<10 mm, where f4 is an effective focus length of the fourth lens. | ||
| 地址 | Tortola, B.V.I. GB | ||