Zoom lens and imaging apparatus including the same

An image pickup apparatus comprising:

• a zoom lens, and
• an image sensor configured to photoelectrically convert an optical image formed by the zoom lens,
• wherein the zoom lens comprises 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;
• an intermediate lens group including a plurality of lens units;
• and
• a last lens unit having a negative refractive power and disposed closest to the image side,
• wherein the zoom lens includes an aperture stop,
• wherein an interval between the lens units adjacent to each other changes during zooming,
• wherein the intermediate lens group includes a negative lens unit having a negative refractive power,
• wherein both the negative lens unit and the last lens unit move to the object side during zooming from a wide-angle end to a telephoto end,
• wherein a lens unit disposed adjacent to the negative lens unit on the object side has a positive refractive power, and
• wherein the following conditional inequalities are satisfied:
• 0.10<fLN/f2<1.20,
• 0.25<ML3/MLN<0.70,
• 0.45<DSPw/TDw<0.95,
• −0.31<Δ2/ΔD1<−0.01, and
• 0.22<fLP/f1<1.70,
• where fLN is a focal length of the negative lens unit, f2 is a focal length of the second lens unit, ML3 is a movement amount of the third lens unit during zooming from the wide-angle end to the telephoto end when focused at infinity, MLN is a movement amount of the negative lens unit during zooming from the wide-angle end to the telephoto end when focused at infinity, DSPw is a distance on an optical axis from the aperture stop to a lens surface of the zoom lens located closest to the image at the wide-angle end, and TDw is a distance on the optical axis from a lens surface of the zoom lens located closest to the object to the lens surface of the zoom lens located closest to the image side at the wide-angle end, ΔD1 is a difference between (a) an interval on the optical axis between a lens surface of the first lens unit located closest to the image and a lens surface of the second lens unit located closest to the obiect at the wide-angle end and (b) an interval on the optical axis between the lens surface of the first lens unit located closest to the image and the lens surface of the second lens unit located closest to the obiect at the telephoto end, and ΔD2 is a difference between (a) an interval on the optical axis between a lens surface of the second lens unit located closest to the image and a lens surface of the third lens unit located closest to the obiect at the wide-angle end and (b) an interval on the optical axis between the lens surface of the second lens unit located closest to the image and the lens surface of the third lens unit located closest to the obiect at the telephoto end, fLP is a focal length of the lens unit disposed adiacent to the negative lens unit on the obiect side, and f1 is a focal length of the first lens unit.