The present disclosure relates to the field of imaging technologies and, particularly, relates to a varifocal optical system. The varifocal optical system includes a front fixing group, a triple prism, a zooming group, a compensating group, an objective lens group and an image plane which are successively arranged along an incident direction of light, and a total focal length of the varifocal optical system is a fixed value; the front fixing group includes a first lens; the zooming group includes a second lens; the compensating group includes a third lens and a fourth lens arranged along an optical path direction; the object lens group includes a fifth lens; and the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all glass lenses. The present disclosure can satisfy the developing trend of miniaturization on electronic devices, and has a better imaging performance.

The present disclosure relates to the field of imaging technologies and, particularly, relates to a varifocal optical system. The varifocal optical system includes a front fixing group, a triple prism, a zooming group, a compensating group, an objective lens group and an image plane which are successively arranged along an incident direction of light, and a total focal length of the varifocal optical system is a fixed value; the front fixing group includes a first lens; the zooming group includes a second lens; the compensating group includes a third lens and a fourth lens arranged along an optical path direction; the object lens group includes a fifth lens; and the first lens, the second lens, the third lens, the fourth lens and the fifth lens are all glass lenses. The present disclosure can satisfy the developing trend of miniaturization on electronic devices, and has a better imaging performance.

Provided is a zoom lens, including, in order from an object side to an image side: a negative first lens unit; a positive second lens unit; a negative third lens unit; a positive fourth lens unit; and a positive fifth lens unit, the first, second, third, fourth, and fifth lens units having an interval between each pair of adjacent lens units changed for zooming. The second, fourth, and fifth lens units are configured to move toward the object side for zooming from a wide-angle end to a telephoto end. A focal length of the fourth lens unit, a focal length of the fifth lens unit, an amount of movement of the fifth lens unit for zooming from the wide-angle end to the telephoto end, and a focal length of an entire system of the zoom lens at the wide-angle end are each appropriately set.

Provided is a zoom lens including, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; a third lens unit having a negative refractive power; a fourth lens unit having a positive refractive power; and a rear lens group including at least one lens unit, the first lens unit, the second lens unit, the third lens unit, the fourth lens unit, and the rear lens group having an interval between each pair of adjacent lens units changed for zooming. The third lens unit is configured to move for focusing, and at least a part of the fourth lens unit forms a lens system IS, which is configured to move in a direction including a component of a direction perpendicular to an optical axis for image stabilization.

An optical system (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. ?020<?F1/?F2<0.50 where ?F1 is the lateral magnification of the first focusing lens group at the time of focusing on the infinite-distance object, and ?F2 is the lateral magnification of the second focusing lens group at the time of focusing on the infinite-distance object.

A zoom lens comprises, in order from an object side: a first lens group G1 having negative refractive power; a second lens group G2 having positive refractive power; a third lens group G3 having negative refractive power and a fourth lens group G4 having positive refractive power. Upon varying magnification, a distance between the first lens group G1 and the second lens group G2, a distance between the second lens group G2 and the third lens group G3 and a distance between the third lens group G3 and the fourth lens group G4 are varied. The second lens group G2 includes, in order from the object side, a front lens group G2F, an aperture stop S, and a rear lens group G2R. Each of the front lens group G2F and the rear lens group G2R includes at least one negative lens. At least a part of the lenses in the second lens group G2 is moved as a movable group to have a component in a direction perpendicular to the optical axis. Thus, the zoom lens can have high optical performances.

A zoom lens includes, in order from an object along an optical axis: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; a fourth lens group; and a fifth lens group. When the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis.

A variable magnification optical system includes: a first lens group (G1) having a negative refractive power; a second lens group (G2) having a positive refractive power; an intermediate group (Gn) disposed closer to an image side than the second lens group (G2); and a vibration-reduction lens group (VR) disposed closer to the image side than the intermediate group (Gn) and configured to be movable so as to have a component in a direction orthogonal to an optical axis. The system performs varying magnification by changing at least the distance between the first lens group (G1) and the second lens group (G2) and the distance between the second lens group (G2) and the intermediate group (Gn), and the system satisfies Conditional Expression (1).

1.500<(Gn)t<100.000 (1) where (Gn)t: an imaging magnification of the intermediate group (Gn) in a telephoto end state

A variable magnification optical system includes: a first lens group (G1) having a negative refractive power; a second lens group (G2) having a positive refractive power; an intermediate group (Gn) disposed closer to an image side than the second lens group (G2); and a vibration-reduction lens group (VR) disposed closer to the image side than the intermediate group (Gn) and configured to be movable so as to have a component in a direction orthogonal to an optical axis. The system performs varying magnification by changing at least the distance between the first lens group (G1) and the second lens group (G2) and the distance between the second lens group (G2) and the intermediate group (Gn), and the system satisfies Conditional Expression (1).

1.000<f(1Gn)t/ft<100.000(1)

A zoom lens comprises a first lens group having negative refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power and a fourth lens group having positive refractive power. Upon varying magnification, distances between the first lens group and the second lens group, between the second lens group and the third lens group and between the third lens group and the fourth lens group vary. The second lens group includes a front lens group, an aperture stop, and a rear lens group. Each of the front lens group and the rear lens group includes at least one negative lens. At least a part of the lenses in the second lens group is moved as a group to have a component in a direction perpendicular to an optical axis.