| 发明名称 | Optical system and image pickup apparatus including the same | ||
| 摘要 | An optical system includes a first lens unit, an aperture stop, and a second lens unit having a positive refractive power. The first lens unit includes a first lens having a negative refractive power and a second lens having a positive refractive power. The second lens unit includes a cemented lens, a fifth lens having a negative refractive power and a concave surface facing an object side, and a sixth lens having a positive refractive power and a convex surface facing an image side. In the cemented lens, a third lens having a positive refractive power and a fourth lens having a negative refractive power are cemented. A distance D1 from an object-side lens surface vertex of the first lens to the aperture stop and a distance Dt from the object-side lens surface vertex of the first lens to an image plane are appropriately set. | ||
| 申请公布号 | US8854747(B2) | 申请公布日期 | 2014.10.07 |
| 申请号 | US201313793092 | 申请日期 | 2013.03.11 |
| 申请人 | Canon Kabushiki Kaisha | 发明人 | Iwamoto Shunji |
| 分类号 | G02B9/64;G02B9/62;G02B13/04;G02B13/22 | 主分类号 | G02B9/64 |
| 代理机构 | Canon USA Inc IP Division | 代理人 | Canon USA Inc IP Division |
| 主权项 | 1. An optical system comprising: a first lens unit; an aperture stop; and a second lens unit having a positive refractive power, wherein the first lens unit, the aperture stop, and the second lens unit are disposed in that order from an object side to an image side, wherein the first lens unit includes a first lens having a negative refractive power and a second lens having a positive refractive power in that order from the object side to the image side, wherein the second lens unit includes a cemented lens, a fifth lens having a negative refractive power, and a sixth lens having a positive refractive power in that order from the object side to the image side, the cemented lens including a third lens having a positive refractive power and a fourth lens having a negative refractive power, the third lens and the fourth lens being cemented to each other, the fifth lens having a concave surface that faces the object side, the sixth lens having a convex surface that faces the image side, and wherein when a distance from an object-side lens surface vertex of the first lens to the aperture stop is D1 and a distance from the object-side lens surface vertex of the first lens to an image plane is Dt, the conditional expression 0.10<D1/Dt<0.25 is satisfied. | ||
| 地址 | Tokyo JP | ||