Patent ID: 9513469
Filing Date: 2016-12-06
CPC Classification: G02B,H04N

Claim Text:
1. A zoom lens comprising in order from an object side to an image side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and a fourth lens unit having a positive refractive power, wherein zooming from a wide angle end to a telephoto end is carried out by changing each distance between the lens units, and the zoom lens is a four-unit zoom lens, and the first lens unit comprises in order from the object side to the image side, a negative lens and a positive lens, and the total number of lenses in the first lens unit is two, and the third lens unit comprises, a positive lens component having a positive refractive power, which is a lens component positioned nearest to the object side in the third lens unit, and a negative lens component having a negative refractive power, which is a lens component positioned nearest to the image side in the third lens unit, and the positive lens component and the negative lens component form a lens block having only two surfaces which make a contact with air in an optical path, namely an object-side surface and an image-side surface, and the following conditional expressions (11), (12), and (13) are satisfied: where, f1p denotes a focal length of the positive lens in the first lens unit, f3p denotes a focal length of the positive lens component in the third lens unit, f1 denotes a focal length of the first lens unit, f2 denotes a focal length of the second lens unit, f3 denotes a focal length of the third lens unit, and h3f denotes an optical axial distance from a surface of incidence of the third lens unit up to a principal point of the third lens unit, and has a negative (minus) sign when the principal point is on the object side of the surface of incidence, and has a positive (plus) sign when the principal point is on the image side of the surface of incidence.