Abstract: A zoom lens adjustment method capable of being applied to zoom lenses for use in video cameras, electronic still cameras, or the like employing solid-state image sensors. An amount of integral movement .delta.1 by which a first lens group (G1) and a second lens group (G2) must axially move from an extreme-wide-angle-state (W) reference positions to cause the actual and reference image planes (IPA and IPR) to coincide is determined. Then, an amount of additional movement .delta.2 by which only the first lens group must be moved to cause the actual and reference image planes to coincide after causing the first and second lens groups to move in integral fashion by the amount .delta.1 when in the extreme-telephoto-state reference positions is determined. Then, from the values of .delta.1 and .delta.

Abstract: A super-wide angle lens, sequentially from an object side, comprises a first negative lens L1, a second negative lens L2, and a third positive lens L3. The first negative lens L1 with its concave surface toward an image side has an image-side surface with a curvature larger than that on an object-side surface. The second negative lens L2 is disposed at a predetermined spacing from the first negative lens L1 and takes a negative meniscus shape with its convex surface toward the object side. The third positive lens L3 has its convex surface toward the object side.

Abstract: A zoom lens comprises, in order from an object side, a first lens group G1 having a negative refracting power, a second lens group G2 having a positive refracting power, a third lens group G3 having a negative refracting power, and a fourth lens group G4 having a positive refracting power. A focal length of the zoom lens is changed from a wide angle end to a telephoto end by changing an air gap between the first lens group G1 and the second lens group G2, increasing an air gap between the second lens group G2 and the third lens group G3, and reducing an air gap between the third lens group G3 and the fourth lens group G4. When a focal length of the first lens group G1 is f1, a focal length of the total lens system at the wide angle end is fw, and an axial air gap between the first lens group G1 and the second lens group G2 in an infinity in-focus state at the wide angle end is D12W, the zoom lens satisfies following conditions: 0.8<.vertline.f1.vertline./fw<1.6, and D12W/fw<0.1.

Abstract: A zoom lens is composed of a first lens group of a negative refractive power, a second lens group of a positive refractive power and a third lens group of a positive refractive power, in which, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases and the distance between the second and third lens groups varies.

Abstract: A zoom lens is provided that is capable of focusing from infinity to an extremely close range, on the order of -0.5 magnification, in all zoom positions with adequate peripheral light amounts and good imaging performance. The zoom lens includes, in the following order, from the object side: 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; and a fourth lens group having a positive refractive power. Zooming from the maximum wide-angle state to the maximum telephoto state is accomplished with the first lens group in a fixed state and the distance between the first lens group and the second lens group decreasing, the distance between the second lens group and the third lens group increasing, and the distance between the third lens group and the fourth lens group decreasing.

Abstract: A zoom lens with antivibration function is provided, in the order from the object side, with a first lens group of a positive refractive power and a second lens group of a negative refractive power, which both axially move toward the object side with a reduction in the gap therebetween in the zooming operation from the wide angle end to the telephoto end. The focusing operation from a larger object distance to a smaller object distance is achieved by an axial movement of the second lens group while the first lens group remains still, while the blur in the taken image resulting from vibration is compensated by a movement of the first lens group in a direction substantially perpendicular to the optical axis.

Abstract: A zoom lens is composed of a first lens group of a negative refractive power, a second lens group of a positive refractive power and a third lens group of a positive refractive power, in which, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases and the distance between the second and third lens groups varies.

Abstract: A zoom lens comprises a first lens group having a positive refracting power, a second lens group having a negative refracting power, and a third lens group having a positive refracting power, disposed in the named order from the object side, wherein the first lens group has a 1-1 lens group having a negative refracting power and a 1-2 lens group having a positive refracting power, disposed in the named order from the object side, wherein zooming from a wide angle end to a telephoto end is effected by increasing a gap between the first lens group and the second lens group and reducing a gap between the second lens group the third lens group, while fixing the first lens group, wherein focusing from infinity to near is effected by moving the 1-1 lens group to the object side; andwherein the following condition is satisfied:0.5<f1/fw<2.

Abstract: A zoom lens structured so that a substantially constant amount of movement of a focusing lens group is required for focusing on objects at the same distance regardless of the zoom position even when an inner focusing method is implemented. The zoom lens includes in order from an object side, a first lens group which has a negative refractive power and a second lens group which has a positive refractive power, wherein zooming is executed by changing a distance between the first lens group and the second lens group, wherein the second lens group includes, in order from the object side, a front group which has a positive refractive power and a rear group which has a positive refractive power, and wherein focusing from an object at a far distance to an object at a close distance is executed by moving the front group towards an image side.

Abstract: A compact zoom lens has a high zoom ratio that is suitable for a single lens reflex camera. Embodiments of the zoom lens include, in order from the object side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, and a third lens unit of positive refractive power, that all move toward the object during zooming from the maximum wide-angle state to the maximum telephoto state, with the distance between the first lens unit and the second lens unit increasing, and the distance between the second lens unit and the third lens unit decreasing; and wherein various conditions are satisfied.

Abstract: A zoom lens is composed of a first lens group of a negative refractive power, a second lens group of a positive refractive power and a third lens group of a positive refractive power, in which, in the zooming operation from the wide angle end to the telephoto end, the distance between the first and second lens groups decreases, the distance between the second and third lens groups varies, the distance between the third and fourth lens groups increases, and the distance between the fourth and fifth lens groups decreases.

Abstract: An inner focus zoom lens is, sequentially from an object side, constructed of a first lens unit exhibiting a negative refracting power, a second lens unit exhibiting a positive refracting power, a third lens unit exhibiting a negative refracting power and a fourth lens unit exhibiting a positive refracting power. Focusing from a long distance object to a short distance object is performed by integrally moving the second lens unit and the third lens unit toward an image-surface direction. Alternatively, an inner focus zoom lens is, sequentially from the object side, constructed of a first lens unit exhibiting a positive refracting power, a second lens unit exhibiting a negative refracting power, a third lens unit exhibiting a positive refracting power and a fourth lens unit exhibiting a positive refracting power. The focusing from the long distance object to the short distance object is effected by integrally moving the second lens unit and the third lens unit toward the image-surface direction.

Abstract: In a phototaking lens with the focal length variable from a predetermined value at the wide-angle end position to another predetermined value at the telephoto end position, a part of lens elements constituting the phototaking lens is rendered movable relative to other lens components. There is provided means for converting the lens, by the relative movement of a part of the lens elements, to a panorama state with a focal length even shorter than that at the wide-angle end position. The phototaking lens is a zoom lens having a first lens group of a positive refractive power and a second lens group of a negative refractive power in the order from the object side, wherein the focal length is varied by a change in the distance between the first and second lens groups, and the panorama state is obtained by a relative movement of the first lens group relative to the second lens group.

Abstract: A zoom lens has an optical axis and at least three lens groups arranged in tandem and capable of being disposed in front of an object. The second lens group counted from the side of the object includes a front lens group and a rear lens group, and either one of said front and rear lens groups constitutes a vibration correcting lens group movable perpendicularly to the optical axis.

Abstract: There is provided a wide-angle zoom lens including in the following order from the object side: a first lens group having a positive refractive power, the first lens group consisting of, in the following order from the object side, a front lens subgroup which consists of a negative lens, and a rear lens subgroup which consists of at least one positive lens and at least one negative lens; and a second lens group having a negative refractive power, wherein an air gap between the first and second lens groups decreases upon zooming from a wide-angle end to a telephoto end, and the zoom lens satisfies the following conditions:0.09.ltoreq.D2/fW.ltoreq.0.4-0.6.ltoreq.Q1.ltoreq.0.

Abstract: A zoom lens with a high zoom ratio has, in the following order from the object 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, and a fourth lens unit having a positive refractive power, and attains zooming from the wide-angle end to the telephoto end by reducing the air gap between the first and second lens units, extending the air gap between the second and third lens units, and reducing the air gap between the third and fourth lens units.

Abstract: A focusing lens position controlling apparatus for a variable focal length lens includes a variable focal length lens having a focusing lens group, a distance measuring device for measuring the object distance information to an object, a focal length detecting device for detecting the focal length information of the variable focal length lens, a first calculating device for calculating an operation coefficient from the output value from the focal length detecting device regarding the focal length information, and a second calculating device for calculating the amount of movement of the focusing lens group from the output value from the distance measuring device regarding the object distance information and the operation coefficient.

Abstract: A zoom lens system includes a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power and a fourth lens group having a positive refracting power. These lens groups are arranged in this order as viewed from an object. During zooming operation from the wide angle end to the telephoto end of the zoom lens system, the air space between the first and second lens groups increases and the air space between the third and fourth lens groups decreases. A focal length equal to the diagonal line of the effective image plane of the zoom lens system is included in the zooming range of the zoom lens system. The zoom lens system is formed so as to satisfy various conditions for making the zoom lens system small and giving a high zoom ratio.

Abstract: A zoom lens includes a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power. In zooming from the wide-angle end to the telephoto end, the distance between the first and second lens groups is increased and the distance between the second and third lens groups is decreased. The second lens group includes a front group having low refractive power and a rear group having positive refractive power. The rear group is movable in a direction almost perpendicular to the optical axis.

Abstract: A telephoto zoom lens includes, in the following order from the object side, a first lens group having a positive refracting power, a second lens group having a negative refracting power, and a third lens group having a positive refracting power. Upon zooming from the wide-angle end to the telephoto end, at least the first and third lens groups move in the object direction, the air distance between the first and second groups increases, and the air distance between the second and third lens groups decreases. The telephoto zoom lens satisfies the following conditions:1.25.ltoreq.f1/fW.ltoreq.1.50-0.37.ltoreq.f2/fW.ltoreq.-0.300.37.ltoreq.f3/fW.ltoreq.0.46where f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and fW is the focal length of the entire system at the wide-angle end.