Abstract: An apparatus has a zoom lens and an image pickup element disposed on the image side of the zoom lens that converts an optical image formed by the zoom lens into an electrical signal. The zoom lens includes, in order from the object side to the image side, a negative first lens unit, a negative second lens unit, a positive third lens unit, and a negative fourth lens unit. During zooming from the wide angle end to the telephoto end, the distance between the first lens unit and the second lens unit changes, the distance between the second lens unit and the third lens unit changes, and the distance between the third lens unit and the fourth lens unit changes, the distance between the second lens unit and the third lens unit being smaller at the telephoto end than at the wide angle end. The first lens unit includes a reflecting surface that deflects the optical path, and the zoom lens satisfies the following condition (1): ?100<fg4/ihw<?2.5 (1).

Abstract: An image pickup apparatus having a wide angle zoom lens system includes a zoom lens system, and an image pickup element which is disposed at an image side of the zoom lens system. The zoom lens system includes in order from an object side thereof, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, a fourth lens unit G4 having a positive refracting power, and an aperture stop S which is disposed between the second lens unit G2 and the third lens unit G3. A zooming is carried out from a wide angle end to a telephoto end by fixing a position of the first lens unit, and changing a distance between the lens units by moving at least the second lens unit G2 and the third lens unit G3, and the following conditional expressions are satisfied. 33°<tan?1(IHw/fw)??(1) 3<f1g/fw<5??(2).

Abstract: A three-unit zoom lens system includes in order from an object side thereof, a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, and a third lens unit having a refracting power. The first lens unit includes a biconcave negative lens component nearest to the object side, and the biconcave negative lens component is the only negative lens component in the first lens unit. The second lens unit includes a cemented lens component which includes in order from the object side thereof, at least three lenses cemented mutually on an optical axis, namely a first positive lens, a negative lens, and a second positive lens. A surface on the image side of the negative lens is a concave surface, and the negative lens has an Abbe's number smaller than the Abbe's number for the first positive lens and the second positive lens, and has a refractive index higher than a refractive index of the second positive lens.

Abstract: A zoom lens, which changes a magnification by properly changing distances between a plurality of lens components, has, in order from the object side, a first lens component with positive power, a second lens component with negative power, a third lens component with positive power, a fourth lens component with positive power, and a fifth lens component with positive power, and the first lens component has a reflecting member changing an optical path. The zoom lens satisfies the following conditions: 1.6<?2(t)/?2(w)<10.0 3.3<?4(t)/?4(w)<10.0 where ?2(t) is a lateral magnification of the second lens component in a telephoto position in infinite focusing, ?2(w) is a lateral magnification of the second lens component in a wide-angle position in infinite focusing, ?4(t) is a lateral magnification of the fourth lens component in the telephoto position in infinite focusing, and ?4(w) is a lateral magnification of the fourth lens component in the wide-angle position in infinite focusing.

Abstract: A zoom lens is such that spacings between a plurality of lens units are properly changed and thereby the magnification of the zoom lens is changed. The most object-side lens unit of this zoom lens has a positive refracting power and comprises, in order from an object side, a negative lens, a reflecting member for changing an optical path, and a positive lens, without cementing the reflecting member and the positive lens as well as the reflecting member and the negative lens, and at least one of surfaces of the negative lens and the positive lens is configured as an aspherical surface to satisfy the following condition: 0.0001<|Y49|/ihw<0.1 where Y49 is an aspherical amount of the aspherical surface at a position where a chief ray of light incident on the most object-side lens unit at an angle of 49° with the optical axis is incident on a most object-side aspherical surface in the lens unit and ihw is an image height at a wide-angle position.

Abstract: A two-unit zoom lens system includes in order from an object side thereof, a first lens unit G1 having a negative refracting power, a second lens unit G2 having a positive refracting power, and an aperture stop which is disposed between the first lens unit G1 and the second lens unit G2, and which moves integrally with the second lens unit. At a time of zooming from a wide angle end to a telephoto end, a distance between the first lens unit G1 and the second lens unit G2 is narrowed. At the time of zooming from the wide angle end to the telephoto end, the first lens unit G1, after moving toward an image side, moves toward an object side. At the time of zooming from the wide angle end to the telephoto end, the second lens unit G2 moves toward the object side. The second lens unit G2 includes in order from the object side thereof, a front sub-unit having a positive refracting power, and a rear sub-unit having a negative refracting power.

Abstract: A zoom lens that has a zoom ratio of the order of 3, and is of sufficiently compact size and improved optical properties. The zoom lens includes, in order from its object side, a first lens unit having negative refracting power, a second lens unit having positive refracting power and a third lens unit having positive refracting power. The space between adjacent lens units is varied for zooming. The first lens unit includes, in order from its object side, one positive lens and one negative lens, and the second lens unit includes, in order from its object side, two positive lenses and one negative lens. The third lens unit includes one positive lens, and satisfies the following condition: 0.5<(R1?R2)/(R1+R2)<0.95. Here, R1 and R2 are the axial radii of curvature of the object- and image-side surfaces of the positive lens in the third lens unit, respectively.

Abstract: A three-unit zoom lens includes, in order from the object side, a negative first lens unit G1, a positive second lens unit G2 and a third lens unit G3, wherein during zooming from the wide angle end to the telephoto end the distance between the first lens unit G1 and the second lens unit G2 decreases and the distance between the second lens unit G2 and the third lens unit G3 changes. The first lens unit G1 is composed of one negative lens component including, in order from the object side, a negative lens having a concave surface directed toward the image side and a positive lens having a convex surface directed toward the object side. The second lens unit G2 includes at least one negative lens and a plurality of positive lenses, wherein at least three lenses among these lenses are cemented to adjacent lenses, the total number of lens components included in the second lens unit G2 is two or less. The third lens unit is composed of one lens component composed of two or less lenses.

Abstract: A zoom lens includes, in order from the object side thereof, a first lens unit G1 having a negative refracting power and a second lens unit G2 having a positive refracting power. During zooming from the wide angle end to the telephoto end, the distance between the first lens unit G1 and the second lens unit G2 decreases. Letting the term “lens component” refer to a lens member whose surfaces that are in contact with air on the optical axis include only two surfaces, one being an object side surface and the other being an image side surface, the first lens unit G1 is comprised of a negative lens component in the form of a cemented lens having a negative refracting power that has, in order from the object side, a negative lens having a concave surface directed toward the image side and a positive lens having a convex surface directed toward the object side, and the second lens unit G2 includes a lens component in the form of a cemented lens having at least one negative lens and a positive lens.

Abstract: An image pickup apparatus having a wide angle zoom lens system includes a zoom lens system, and an image pickup element which is disposed at an image side of the zoom lens system. The zoom lens system includes in order from an object side thereof, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, a fourth lens unit G4 having a positive refracting power, and an aperture stop S which is disposed between the second lens unit G2 and the third lens unit G3. A zooming is carried out from a wide angle end to a telephoto end by fixing a position of the first lens unit, and changing a distance between the lens units by moving at least the second lens unit G2 and the third lens unit G3, and the following conditional expressions are satisfied. 33°<tan?1(IHw/fw)??(1) 3<f1g/fw<5??(2).

Abstract: A three-unit zoom lens system includes in order from an object side thereof, a first lens unit G1 having a negative refracting power, a second lens unit G2 having a positive refracting power, a third lens unit G3 having a positive refracting power or a negative refracting power, and an aperture stop which is on an image plane side of the first lens unit G1, and on an object side of a lens surface nearest to the image side, of the second lens unit G2, and which moves integrally with the second lens unit. At the time of zooming from the wide angle end to the telephoto end, a distance between the first lens unit G1 and the second lens unit G2 is narrowed, and a distance between the second lens unit G2 and the third lens unit G3 changes. The second lens unit G2 moves toward the object side at the time of zooming from the wide angle end to the telephoto end. The second lens unit includes a positive lens made of plastic, which is disposed nearest to the object.

Abstract: A two-unit zoom lens system includes in order from an object side thereof, a first lens unit G1 having a negative refracting power, a second lens unit G2 having a positive refracting power, and an aperture stop which is disposed between the first lens unit G1 and the second lens unit G2, and which moves integrally with the second lens unit. At a time of zooming from a wide angle end to a telephoto end, a distance between the first lens unit G1 and the second lens unit G2 is narrowed. At the time of zooming from the wide angle end to the telephoto end, the first lens unit G1, after moving toward an image side, moves toward an object side. At the time of zooming from the wide angle end to the telephoto end, the second lens unit G2 moves toward the object side. The second lens unit G2 includes in order from the object side thereof, a front sub-unit having a positive refracting power, and a rear sub-unit having a negative refracting power.

Abstract: A three-unit zoom lens system includes in order from an object side thereof a first lens unit G1 having a negative refracting power, a second lens unit G2 having a positive refracting power, a third lens unit G3 having a negative refracting power, and an aperture stop which is at an image side of the first lens unit G1, and at the object side of a lens surface nearest to the image side of the second lens unit G2, and which moves integrally with the second lens unit. At a time of zooming from a wide angle end to a telephoto end, a distance between the first lens unit G1 and the second lens unit G2 is narrowed, and a distance between the second lens unit G2 and the third lens unit G3 changes. The second lens unit G2 moves toward the object side at the time of zooming from the wide angle end to the telephoto end. The third lens unit G3 moves to be positioned at the object side at the telephoto end, with respect to the wide angle end.

Abstract: A three-unit zoom lens system includes in order from an object side thereof, a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, and a third lens unit having a refracting power. The first lens unit includes a biconcave negative lens component nearest to the object side, and the biconcave negative lens component is the only negative lens component in the first lens unit. The second lens unit includes a cemented lens component which includes in order from the object side thereof, at least three lenses cemented mutually on an optical axis, namely a first positive lens, a negative lens, and a second positive lens. A surface on the image side of the negative lens is a concave surface, and the negative lens has an Abbe's number smaller than the Abbe's number for the first positive lens and the second positive lens, and has a refractive index higher than a refractive index of the second positive lens.

Abstract: There is disclosed a zoom lens system including, in order from an object 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, and further including an aperture stop S disposed between the second lens unit and the third lens unit, during zooming from a wide-angle end to a telephoto end, a space between the lens units is changed, the first lens unit includes a single lens having a negative refractive power, a reflective optical element having a reflective surface which reflects an optical path and a sub unit having a positive refractive power, and the zoom lens system satisfies predetermined conditions.

Abstract: The invention concerns a zoom lens that has a zoom ratio of the order of 3, and is of sufficiently compact size and improved optical properties. The zoom lens comprises, in order from its object side, a first lens unit having negative refracting power, a second lens unit having positive refracting power and a third lens unit having positive refracting power, wherein the space between adjacent lens units is varied for zooming. The first lens unit consists of, in order from its object side, one positive lens and one negative lens, and the second lens unit consists of, in order from its object side, two positive lenses and one negative lens. The third lens unit consists of one positive lens, and satisfies the following condition. 0.5<(R1?R2)/(R1+R2)<0.95 Here R1 and R2 are the axial radii of curvature of the object- and image-side surfaces of the positive lens in the third lens unit, respectively.

Abstract: There is disclosed a zoom lens system including, in order from an object 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, and further including an aperture stop S disposed between the second lens unit and the third lens unit, during zooming from a wide-angle end to a telephoto end, a space between the lens units is changed, the first lens unit includes a single lens having a negative refractive power, a reflective optical element having a reflective surface which reflects an optical path and a sub unit having a positive refractive power, and the zoom lens system satisfies predetermined conditions.

Abstract: The invention concerns a zoom lens that has a zoom ratio of the order of 3, and is of sufficiently compact size and improved optical properties. The zoom lens comprises, in order from its object side, a first lens unit having negative refracting power, a second lens unit having positive refracting power and a third lens unit having positive refracting power, wherein the space between adjacent lens units is varied for zooming. The first lens unit consists of, in order from its object side, one positive lens and one negative lens, and the second lens unit consists of, in order from its object side, two positive lenses and one negative lens. The third lens unit consists of one positive lens, and satisfies the following condition. 0.5<(R1?R2)/(R1+R2)<0.95 Here R1 and R2 are the axial radii of curvature of the object- and image-side surfaces of the positive lens in the third lens unit, respectively.

Abstract: The invention relates to a small-format, low-cost zoom lens that can gain sufficient telecentricity and aberration performance even with the use of an inexpensive vitreous material, and so lends itself to an electronic image pickup device. The zoom lens comprises a first lens group G1 of negative refracting power, a second lens group G2 of positive refracting power and a third lens group G3 of positive refracting power. For zooming, the lens groups are moved with a change in the spacing between adjacent lens groups. The second lens group G2 comprises a first lens of positive refracting power, a second lens of positive refracting power and a third lens group of negative refracting power, and has three lenses in all. The third lens group G3 comprises a positive lens that is of meniscus shape convex toward an image plane of the zoom lens system and satisfies condition (3), n?1.53.

Abstract: The invention concerns a zoom lens that has a zoom ratio of the order of 3, and is of sufficiently compact size and improved optical properties. The zoom lens comprises, in order from its object side, a first lens unit having negative refracting power, a second lens unit having positive refracting power and a third lens unit having positive refracting power, wherein the space between adjacent lens units is varied for zooming. The first lens unit consists of, in order from its object side, one positive lens and one negative lens, and the second lens unit consists of, in order from its object side, two positive lenses and one negative lens. The third lens unit consists of one positive lens, and satisfies the following condition. 0.5<(R1?R2)/(R1+R2)<0.95 Here R1 and R2 are the axial radii of curvature of the object- and image-side surfaces of the positive lens in the third lens unit, respectively.