Abstract: A zoom lens system according to the present invention, from an object side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth units all move along the optical axis. The third lens unit is composed of three or more lens elements. The condition (6): nd8?1.5 and vd8?75 and the condition (7): (nd9?1)+(nd10?1)?1.55 are satisfied (where, 16<fT/fW, ?>35, and in the third lens unit: nd8, nd9, nd10 are refractive indices to the d-line of the lens elements located on the most object side and at the second and the third positions from the object side; vd8 is an Abbe number to the d-line of the lens element on the most object side; ? is a half view angle at a wide-angle limit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit).

Abstract: A zoom lens system according to the present invention, from an object side to an image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth lens units all move along the optical axis. The condition (8): 0.15<dG3/dG<0.27 is satisfied (where, 16<fT/fW, ?>35; dG3 is an optical axial center thickness of the third lens unit; dG is a sum of the optical axial thicknesses of the first to the fourth lens units; ? is a half view angle at a wide-angle limit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit). As a result, the zoom lens system has a reduced size and still realizes a wide view angle at a wide-angle limit, as well as a remarkably high zooming ratio and high performance.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein: the first lens unit comprises a first lens element having a concave surface at least on the image side and negative power and a second lens element having a convex surface at least on the object side and positive power; the second lens unit comprises a single third lens element, a cemented lens element of two lens elements having power of mutually different signs and a single sixth lens element; in zooming, all of the lens units move along an optical axis; and conditions (1): 5.0<?iW<20.0 and (I-2): n11?1.9 (where, 3.

Abstract: A zoom lens has a field view of 60° to 70° at a wide-angle end, a magnification change ratio of about five to six times, and a small number of component lenses, enables retraction to a compact size when not in use, provides high resolution, and is compatible with a compensation function for zoom lens vibrations. Comprised are, in order from an object side, a first lens unit (G1) of positive optical power, a second lens unit (G2) of negative optical power, a third lens unit (G3) of positive optical power, and a fourth lens unit (G4) of positive optical power. When zooming from the wide-angle end to a telephoto end, the first lens unit (G1) and the second lens unit (G2) move so as to trace a convex path toward an image side, and the third lens unit and the fourth lens unit (G4) move monotonously toward an object side.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein: the first lens unit comprises a first lens element having a concave surface at least on the image side and negative power and a second lens element having a convex surface at least on the object side and positive power; the second lens unit comprises a cemented lens element fabricated by two lens elements having optical power of mutually different signs and one single lens element; in zooming, all of the lens units move along an optical axis; and conditions (1): 5.0<?iW<20.0 and (I-2): n11?1.9 (where, 3.

Abstract: An object is to provide: a zoom lens system that has a reduced overall length, a high resolution, and a variable magnification ratio as high as 9 or greater and that is satisfactorily adaptable for wide-angle image taking where the view angle at a wide-angle limit is 70° or greater; an imaging device employing this zoom lens system; and a thin and compact camera. The zoom lens system has a plurality of lens units each consisting of at least one lens element, and, in order from the object side to the image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit and a fifth lens unit. In zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit and the second lens unit move in an optical axis direction, while the fourth lens unit and the fifth lens unit are each consists of one lens element.

Abstract: An object is to provide: a zoom lens system that has a reduced overall length, a high resolution, and a variable magnification ratio as high as 9 or greater and that is satisfactorily adaptable for wide-angle image taking where the view angle at a wide-angle limit is 70° or greater; an imaging device employing this zoom lens system; and a thin and compact camera. The zoom lens system has a plurality of lens units each consisting of at least one lens element, and, in order from the object side to the image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit and a fifth lens unit. In zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit and the second lens unit move in an optical axis direction, while the fourth lens unit and the fifth lens unit are each consists of one lens element.

Abstract: The zoom lens system is used for forming an optical image of an object with a variable magnification, and, in order from the object side, comprises a first lens unit G1 of negative optical power, a second lens unit G2 of positive optical power and a third lens unit G3 of positive optical power. The lens units move respectively along the optical axis so that a magnification is changed with changing a distance between the respective lens units. The second lens unit G2 comprises at least three lens elements including an object side lens element of the second lens unit which is a positive lens element arranged on the most object side with the surface of strong curvature facing the object side, and an image side lens element of the second lens unit which is a positive lens element arranged on the most image side with the convex surface facing the object side.

Abstract: A zoom lens system comprising a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units among the lens units is changed so that an optical image of an object is formed with a continuously variable magnification, a first lens unit arranged on the most object side among the lens units includes a lens element having a reflecting surface for bending a light beam from the object, and any one of the lens units, any one of the lens elements, or alternatively a plurality of adjacent lens elements that constitute one lens unit move in a direction perpendicular to an optical axis; an imaging device including the zoom lens system; and a camera employing the imaging device.

Abstract: A zoom lens system comprising a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units among the lens units is changed so that an optical image of an object is formed with a continuously variable magnification, a first lens unit arranged on the most object side among the lens units includes a lens element having a reflecting surface for bending a light beam from the object, and any one of the lens units, any one of the lens elements, or alternatively a plurality of adjacent lens elements that constitute one lens unit move in a direction perpendicular to an optical axis; an imaging device including the zoom lens system; and a camera employing the imaging device.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit decreases while an interval between the second lens unit and the third lens unit changes so that variable magnification is achieved, the first lens unit comprises one object side negative lens element and one image side positive lens element with a convex surface facing the object side, which have an aspheric surface, and the conditions: n12>1.88 and ?12<26 (n12 and ?12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Abstract: An object is to provide: a zoom lens system that has a reduced overall length, a high resolution, and a variable magnification ratio as high as 9 or greater and that is satisfactorily adaptable for wide-angle image taking where the view angle at a wide-angle limit is 70° or greater; an imaging device employing this zoom lens system; and a thin and compact camera. The zoom lens system has a plurality of lens units each consisting of at least one lens element, and, in order from the object side to the image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit and a fifth lens unit. In zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit and the second lens unit move in an optical axis direction, while the fourth lens unit and the fifth lens unit each consists of one lens element.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein: the first lens unit comprises a first lens element having a concave surface at least on the image side and negative power and a second lens element having a convex surface at least on the object side and positive power; the second lens unit comprises a first cemented lens element of two lens elements having power of mutually different signs and a second cemented lens element of two lens elements having power of mutually different signs; in zooming, all of the lens units move along an optical axis; and conditions (1): 5.0<?iW<20.0 and (I-2): n11?1.9 (where, 3.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein: the first lens unit comprises a first lens element having a concave surface at least on the image side and negative power and a second lens element having a convex surface at least on the object side and positive power; the second lens unit comprises a first cemented lens element of two lens elements having power of mutually different signs and a second cemented lens element of two lens elements having power of mutually different signs; in zooming, all of the lens units move along an optical axis; and conditions (1): 5.0<?iW<20.0 and (I-2): n11?1.9 (where, 3.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit decreases while an interval between the second lens unit and the third lens unit changes so that variable magnification is achieved, the first lens unit comprises one object side negative lens element and one image side positive lens element with a convex surface facing the object side, which have an aspheric surface, and the conditions: n12>1.88 and ?12<26 (n12 and ?12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit decreases while an interval between the second lens unit and the third lens unit changes so that variable magnification is achieved, the first lens unit comprises one object side negative lens element and one image side positive lens element with a convex surface facing the object side, which have an aspheric surface, and the conditions: n 12>1.88 and ? 12<26 (n12 and ?12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit decreases while an interval between the second lens unit and the third lens unit changes so that variable magnification is achieved, the first lens unit comprises one object side negative lens element and one image side positive lens element with a convex surface facing the object side, which have an aspheric surface, and the conditions: n12>1.88 and ?12<26 (n12 and ?12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Abstract: A zoom lens system comprising a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units is changed so that an optical image is formed with a continuously variable magnification, the zoom lens system comprises a first lens unit having positive power, a second lens unit that includes a lens element having a reflecting surface and has negative power and subsequent lens units including at least one lens unit having positive power, and the condition: 0.50<(C?S)/H<1.00(C=?{square root over ( )}(2R·dR?dR2), S is a sag of the image side surface of the most object side lens element in the second lens unit at height H, H is one-half of an optical axial thickness of the lens element having a reflecting surface, R is a radius of curvature of the image side surface, and dR is an interval between the most object side lens element and the lens element having a reflecting surface) is satisfied.

Abstract: A zoom lens system comprising a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units is changed so that an optical image is formed with a continuously variable magnification, the zoom lens system comprises a first lens unit having positive power, a second lens unit that includes a lens element having a reflecting surface and has negative power and subsequent lens units including at least one lens unit having positive power, and the condition: 0.50<(C?S)/H<1.00(C=?{square root over ( )}(2R·dR?dR2), S is a sag of the image side surface of the most object side lens element in the second lens unit at height H, H is one-half of an optical axial thickness of the lens element having a reflecting surface, R is a radius of curvature of the image side surface, and dR is an interval between the most object side lens element and the lens element having a reflecting surface) is satisfied.

Abstract: An imaging optical system according to the present invention is provided with at least one lens element and comprises: an optical surface through which incident light transmits; and an antireflection structure provided in at least part of a peripheral region located in the periphery of a center region containing the center of an optical surface in one or more optical surfaces, wherein the peripheral region is within an optical effective diameter, and wherein the antireflection structure is a structure in which structural units having a predetermined shape are arranged periodically in the form of an array at a period smaller than a minimum wavelength of light whose reflection should be prevented in the incident light.