Patent ID: 8675117
Filing Date: 2014-03-18
Classification: G02B

Abstract:
1. An imaging unit comprising: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a solid-state imaging device that images an optical image formed by the first lens group to the third lens group sequentially arranged along an optical axis from an object side toward an image side, wherein, the second lens group is disposed in a fixed, stationary position on the optical axis and between the first lens group and the third lens group and the third lens group is disposed between the second lens group and the solid-state imaging device, wherein the first lens group, the third lens group and the solid-state imaging device are movable along the optical axis and relative to the second lens group in the fixed, stationary position to and between a wide-angle end state and a telephoto end state, wherein, at the wide-angle end state, the solid-state imaging device is disposed apart from the second lens group at a first distance and while zooming from the wide-angle end state to the telephoto end state, the first lens group moves away from the second lens group, the third lens group moves towards the second lens group and the solid-state imaging device moves along the optical axis into a solid-state imaging device position disposed away from the second lens group at a second distance being less than the first distance, wherein the first lens group includes a first lens group cemented lens formed by cementing a first lens group negative lens having a meniscus shape with a first lens group negative lens convex surface directed toward the object side and a first lens group first positive lens having a meniscus shape with a first lens group first positive lens convex surface directed toward the object side and a first lens group second positive lens having a meniscus shape with a first lens group second positive lens convex surface directed toward the object side and sequentially arranged from the object side toward the image side, wherein the second lens group includes a second lens group first negative lens having a meniscus shape with a second lens group first negative lens concave surface directed toward the image side and a second lens group cemented lens formed by cementing a second lens group second negative lens having a meniscus shape with a second lens group second negative lens concave surface directed toward the object side and a second lens group positive lens having a meniscus shape with a second lens group positive lens convex surface directed toward the object side and sequentially arranged from the object side toward the image side and wherein the third lens group includes a third lens group cemented lens formed by cementing a third lens group first positive lens having a meniscus shape with a third lens group first positive lens convex surface directed toward the object side and a third lens group first negative lens having a meniscus shape with a third lens group first negative lens concave surface directed toward the object side, a third lens group second positive lens having a biconvex shape and a third lens group second negative lens with a third lens group second negative lens concave surface directed toward the object side and sequentially arranged from the object side toward the image side.