Zoom lens and image pickup apparatus including the same

A zoom lens, comprising in order from an object side to an image side:

• a first lens unit including a focusing lens unit and having a positive refractive power;
• a second lens unit having a negative refractive power and moving for magnification-varying;
• a third lens unit moving for magnification-varying;
• and
• a fourth lens unit having a positive refractive power,
• wherein the second lens unit comprises five lenses as a whole including a first lens having a negative refractive power and a second lens having a negative refractive power, and the first lens and the second lens are disposed successively in order from the object side to the image side, and
• wherein the following conditional expressions are satisfied:
• 8.0<f1/|f2|<13.5;
• 0.65<f2n/f2<1.85;
• and
• 0.03<O12/D2<0.18,
• where f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, f2n represents a combined focal length of the first lens and the second lens, O12 represents a distance from a lens surface vertex of the first lens on the object side to an object side principal point position of the second lens unit, and D2 represents a thickness of the second lens unit on an optical axis.

An image pickup apparatus, comprising:

• a zoom lens comprising in order from an object side to an image side:
• a first lens unit including a focusing lens unit and having a positive refractive power;
• a second lens unit having a negative refractive power and moving during zooming;
• a third lens unit moving during zooming;
• and
• a fourth lens unit having a positive refractive power,
• wherein the second lens unit comprises four lenses as a whole including a first lens having a negative refractive power and a second lens having a negative refractive power, and the first lens and the second lens are disposed adjacent to each other in order from the object side to the image side, and wherein the following conditional expressions are satisfied:
• 7.8<f1/|f2|<12.0;
• 1.20<f21/f2<1.63;
• and
• 0.04<O12/D2<0.15,
• where f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, f21 represents a focal length of the first lens, 012 represents a distance from a lens surface vertex of the first lens on the object side to an object side principal point position of the second lens unit, and D2 represents a thickness of the second lens unit on an optical axis;
• and
• a solid-state image pickup element for receiving light of an image formed by the zoom lens.

An image pickup apparatus, comprising:

• a zoom lens comprising in order from an object side to an image side:
• a first lens unit including a focusing lens unit and having a positive refractive power;
• a second lens unit having a negative refractive power and moving during zooming;
• a third lens unit moving during zooming;
• and
• a fourth lens unit having a positive refractive power, wherein the second lens unit comprises five lenses as a whole including a first lens having a negative refractive power and a second lens having a negative refractive power, and the first lens and the second lens are disposed adjacent to each other in order from the object side to the image side, and wherein the following conditional expressions are satisfied:
• 8.0<f1/|f2 |<13.5;
• 0.65<f2n/f2<1.85;
• and
• 0.03<O12/D2<0.18,
• where f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, f2n represents a combined focal length of the first lens and the second lens, 012 represents a distance from a lens surface vertex of the first lens on the object side to an object side principal point position of the second lens unit, and D2 represents a thickness of the second lens unit on an optical axis;
• and
• a solid-state image pickup element for receiving light of an image formed by the zoom lens.

A zoom lens, comprising in order from an object side to an image side:

• a first lens unit including a focusing lens unit and having a positive refractive power;
• a second lens unit having a negative refractive power and moving during zooming;
• a third lens unit moving during zooming;
• and
• a fourth lens unit having a positive refractive power, wherein the second lens unit comprises plural lenses including a first lens having a negative refractive power which is disposed at the most object side, and
• wherein the following conditional expressions are satisfied:
• 7.8<f1/|f2|<12.0;
• 1.20<f21/f2<1.63;
• and
• 0.04<O12/D2<0.15,
• where f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, f21 represents a focal length of the first lens, O12 represents a distance from a lens surface vertex of the first lens on the object side to an object side principal point position of the second lens unit, and D2 represents a thickness of the second lens unit on an optical axis.

A zoom lens, comprising in order from an object side to an image side:

• a first lens unit including a focusing lens unit and having a positive refractive power;
• a second lens unit having a negative refractive power and moving during zooming;
• a third lens unit moving during zooming;
• and
• a fourth lens unit having a positive refractive power, wherein the second lens unit comprises plural lenses including a first lens having a negative refractive power which is disposed at the most object side, and a second lens having a negative refractive power, and
• wherein the following conditional expressions are satisfied:
• 8.0<f1/|f2|<13.5;
• 0.65<f2n/f2<1.85;
• and
• 0.03<O12/D2<0.18,
• where f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, f2n represents a combined focal length of the first lens and the second lens, O12 represents a distance from a lens surface vertex of the first lens on the object side to an object side principal point position of the second lens unit, and D2 represents a thickness of the second lens unit on an optical axis.

An image pickup apparatus, comprising:

• a zoom lens, comprising in order from an object side to an image side:
• a first lens unit including a focusing lens unit and having a positive refractive power;
• a second lens unit having a negative refractive power and moving during zooming;
• a third lens unit moving during zooming;
• and
• a fourth lens unit having a positive refractive power,
• wherein the second lens unit comprises plural lenses including a first lens having a negative refractive power which is disposed at the most object side, and wherein the following conditional expressions are satisfied:
• 7.8<f1|f2|<12.0;
• 1.20<f21/f2<1.63;
• and
• 0.04<O12/D2<0.15,
• where f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, f21 represents a focal length of the first lens, O12 represents a distance from a lens surface vertex of the first lens on the object side to an object side principal point position of the second lens unit, and D2 represents a thickness of the second lens unit on an optical axis;
• and
• a solid-state image pickup element for receiving light of an image formed by the zoom lens.