Abstract: The toner contains binder resin-containing toner particles and silica fine particle S1, wherein the weight-average particle diameter of the toner is 4.0-15.0 ?m, both inclusive, peaks originating with the silica fine particle S1 are observed in 29 Si-NMR measurement of the silica fine particle S1, and, in the spectrum obtained by 29Si CP/MAS NMR or 29Si DD/MAS NMR, the peak area of a peak corresponding to the D1 unit structure in the silica fine particle S1, the peak area of a peak corresponding to the D2 unit structure in the silica fine particle S1, and the peak area of a peak corresponding to the Q unit structure in the silica fine particle S1 satisfy a prescribed relationship.

Abstract: A communication device includes a zoom lens that collects signal light.

Abstract: A communication device includes a zoom lens that collects signal light.

Abstract: A zoom lens of high zoom ratio that has high quality in imaging performance and achieved downsizing and cost reduction at the same time. The zoom lens includes a positive first lens group to a positive fourth lens group achieves a predetermined zoom ratio by moving all lens groups along the optical axis direction backward and forward in magnification change, wherein the first lens group includes the negative lens, the positive lens and the positive lens; the second lens group includes at least two negative lenses and one positive lens; the third lens group includes two positive biconvex lenses and the negative lens in order from the object side and. The following conditional expression (1) and conditional expression (2) are satisfied: -42?f123t/f4×Z?-25??(1) 8.2?f3/f4×Z?13.

Abstract: The present invention is directed to an imaging lens with an optical system that comprises the foremost lens group closest to an object and of positive refractivity, the succeeding middle lens group, and the rearmost lens group closest to an image plane and of negative refractivity where the middle lens group, having the first, second, and third lens subgroups disposed in series, is moved axially along the optical axis for focusing, and the foremost lens group includes at least three or more convex lens pieces and a single concave lens piece and meets predetermined requirements defined in formulae. The imaging lens has a quality image stabilizing system in which a light-weight lens piece(s) is moved in directions perpendicular to the optical axis.

Abstract: A high-power zoom lens that achieves size and price reduction, and at the same time provides high-quality imaging. This lens includes at least four lens groups arranged along an optical axis, which are moveable along the axis in order to achieve changes in magnification. The first, third, and fourth lens groups have positive refractive powers, and the second group has a negative refractive power. The second lens group includes a negative meniscus lens arranged closest to the object, provided with a convex surface at the object side. A negative lens is arranged next to the negative meniscus lens, and a negative lens provided with a concave surface at the object side is arranged closest to the image. The fourth lens group includes at least two positive lenses and one negative lens.

Abstract: A fixed focus lens comprising, sequentially from an object side, a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a third lens group having a positive refractive power. The first lens group includes an aperture stop. The second lens group is configured by a single lens element. During focusing, the second lens group moves along an optical axis and the first lens group and the third lens group are fixed with respect to an imaging plane.

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, in order from an object side to an image side, a first lens unit having positive optical power and composed of not more than two lens elements, a second lens unit having negative optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power. In zooming from a wide-angle limit to a telephoto limit, the fourth lens unit moves along an optical axis. Further, the following conditions are satisfied: 1.50<nd1<1.72, 50<vd1<75 (nd1: a refractive index to the d line of a positive lens element constituting the first lens unit, vd1: an Abbe number of a positive lens element constituting the first lens unit).

Abstract: A fixed focus lens includes an M group that is disposed at a center of the optical system and has a positive refractive power; an F group that is disposed farther on the image plane side than the M group, has a negative refractive power, and is moved along the optical axis during focusing; a V group that is disposed farther on the object side than the M group, has a negative refractive index, and is moved in a direction orthogonal to the optical axis during vibration control; and an FC group that is disposed farther on the object side than the V group and has a positive refractive power. The V group is configured by a single lens element, and during focusing, at least the FC group and the M group are fixed.

Abstract: A high-power zoom lens that achieves size and price reduction, and at the same time provides high-quality imaging. This lens includes at least four lens groups arranged along an optical axis, which are moveable along the axis in order to achieve changes in magnification. The first, third, and fourth lens groups have positive refractive powers, and the second group has a negative refractive power. The second lens group includes a negative meniscus lens arranged closest to the object, provided with a convex surface at the object side. A negative lens is arranged next to the negative meniscus lens, and a negative lens provided with a concave surface at the object side is arranged closest to the image. The fourth lens group includes at least two positive lenses and one negative lens.

Abstract: A fixed focus lens comprising, sequentially from an object side, a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a third lens group having a positive refractive power. The first lens group includes an aperture stop. The second lens group is configured by a single lens element. During focusing, the second lens group moves along an optical axis and the first lens group and the third lens group are fixed with respect to an imaging plane.

Abstract: A fixed focus lens comprising, sequentially from an object side, a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a third lens group having a positive refractive power. The first lens group includes an aperture stop. The second lens group is configured by a single lens element. During focusing, the second lens group moves along an optical axis and the first lens group and the third lens group are fixed with respect to an imaging plane.

Abstract: A compact imaging optical system having a light-weight focusing lens is provided. The imaging optical system includes, in order from an object side to an image side, a front unit in which a negative lens element is arranged closest to the object side, an aperture diaphragm, and a rear unit having positive optical power. In focusing from an infinite distance object to a short distance object, the negative lens element arranged closest to the object side and the aperture diaphragm are fixed with respect to an image surface, and a part of lens elements included in the front unit or the rear unit moves along an optical axis. The imaging optical system satisfies the following condition (1): 0.9<R/f<2.0 (R: an average between an image side curvature radius of the negative lens element arranged closest to the object side, and an image side curvature radius of a second negative lens element from the object side among all the negative lens elements; f: a focal length of the entire system).

Abstract: A zoom lens system comprising: a first lens unit having negative optical power; a second lens unit; and at least one subsequent lens unit, wherein in zooming, the first lens unit moves along an optical axis, and at least an interval between the second lens unit and a lens unit which is one of the at least one subsequent lens unit varies, in focusing, an interval between the first lens unit and the second lens unit varies, at least one aspheric surface is included in the at least one subsequent lens unit, and the condition: 0.1<d1W/d2W<0.4 (d1W, d2W: an air space between the first lens unit and the second lens unit, an air space between the second lens unit and the lens unit which is one of the at least one subsequent lens unit and is located closest to the object side, at a wide-angle limit, in an infinity in-focus condition) is satisfied; an interchangeable lens apparatus; and a camera system are provided.

Abstract: Provided is a zoom lens system including a compact focusing lens unit and having a suppressed change in image magnification at the time of movement of the focusing lens unit. The zoom lens system of the present invention, in order from an object side to an image side, includes, a first lens unit G1 having positive optical power, a second lens unit G2 having negative optical power, a third lens unit G3 having negative optical power, and a fourth lens unit G4. Further, condition: 1.88<nd2 is satisfied (where, nd2 is an average refractive index of a lens element (a portion excluding a resin layer in the case of a hybrid lens) included in the second lens unit G2).

Abstract: A fixed focus lens includes an M group that is disposed at a center of the optical system and has a positive refractive power; an F group that is disposed farther on the image plane side than the M group, has a negative refractive power, and is moved along the optical axis during focusing; a V group that is disposed farther on the object side than the M group, has a negative refractive index, and is moved in a direction orthogonal to the optical axis during vibration control; and an FC group that is disposed farther on the object side than the V group and has a positive refractive power. The V group is configured by a single lens element, and during focusing, at least the FC group and the M group are fixed.

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, a first lens unit having positive optical power and arranged closest to an object side, a focusing lens unit that moves along an optical axis from an infinity in-focus condition to a close-object in-focus condition, an image blur compensation sub-lens unit that includes at least one lens element and that moves in a direction perpendicular to the optical axis, and an aperture diaphragm arranged on an image side relative to the focusing lens unit and the image blur compensation sub-lens unit. The focusing lens unit, the image blur compensation sub-lens unit, and the aperture diaphragm are adjacent with one another. Further, the following condition (8) is satisfied: 0.7<BFW/fW<3.

Abstract: A fixed focus lens comprising, sequentially from an object side, a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a third lens group having a positive refractive power. The first lens group includes an aperture stop. The second lens group is configured by a single lens element. During focusing, the second lens group moves along an optical axis and the first lens group and the third lens group are fixed with respect to an imaging plane.

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, in order from an object side to an image side, a first lens unit having positive optical power and composed of not more than two lens elements, a second lens unit having negative optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power. In zooming from a wide-angle limit to a telephoto limit, the fourth lens unit moves along an optical axis. Further, the following condition (9) and (10) are satisfied: 1.50<nd1<1.72, 50<vd1<75 (nd1: a refractive index to the d line of a positive lens element constituting the first lens unit, vd1: an Abbe number of a positive lens element constituting the first lens unit).

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having negative optical power, a fourth lens unit having positive optical power and including at least one resin lens, and an aperture diaphragm arranged in the fourth lens unit. In zooming from a wide-angle limit to a telephoto limit, an interval between the third lens unit and the fourth lens unit monotonically decreases. Further, the following condition (1) is satisfied: 1.0<T4/fW<3.5 (T4: a thickness of the fourth lens unit in an optical axis direction, fW: a focal length of the entire system at a wide-angle limit).