Abstract: The zoom lens is composed of: an object side lens group at least including, in order from an object side: a first lens group G1 having positive refractive power; and a second lens group G2 having negative refractive power; and an image focusing side lens group including, in order from the object side: a negative lens group A having negative refractive power; and a negative lens group B arranged by facing the negative lens group A across an air distance, having negative refractive power. In the zoom lens, focusing from infinity to a close object is achieved by moving just the negative lens group A toward an image focusing side to satisfy a conditional expression below: [Expression 1] ?1.80<?2t<?0.94??(1) (1??At2)×?Bt2<?4.

Abstract: A zoom lens includes sequentially from an object side, a first lens section G11 having a negative refractive power and a second lens section G12 having a positive refractive power. The first lens section G11 includes sequentially from the object side, a negative lens L111, a negative lens L112, and a positive lens L113. Both surface of the negative lens L112 are aspheric. The second lens section G12 includes sequentially from the object side, a front group G12F having a positive refractive power and a rear group G12R having a positive refractive power. Both surfaces of a negative lens L126 included in the rear group G12R are aspheric. The zoom lens can maintain high imaging performance while achieving size reductions and wide angle views by satisfying given conditions.

Abstract: Provided are: a zoom lens which exhibits a large variable-power ratio, an increased degree of freedom with respect to aberration correction, and which has been achieved having a sufficient reduction in size in the optical axis direction; and an imaging device equipped therewith. The zoom lens includes at least, from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group, and a fifth lens group, in that order. In the zoom lens, prescribed conditions are satisfied.

Abstract: The invention provides an infrared fixed-focus lens of which component lens pieces are made of germanium characterized by low chromatic dispersion, and have no surface processed to serve as diffraction optics. The infrared fixed-focus lens comprises a first lens piece disposed closer to an object and of negative power, and a second lens piece disposed closer to the image plane and of positive power. Both the first and second lens pieces are made of germanium.

Abstract: A zoom lens includes sequentially from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a negative refractive power. The zoom lens varies the interval between the lens groups to perform zooming; shifts the second lens group in a direction substantially orthogonal to the optical axis to correct image blur occurring with optical system vibrations; and satisfies given conditions, enabling a compact size and a high zoom ratio to be achieved while improving imaging performance.

Abstract: To provide an anti-vibration actuator capable of smooth transition to image-blur prevention control. The present invention is an actuator (10) furnished with a locking mechanism, including: a fixed portion (12); a movable portion (14) with an image-blur prevention lens (16); a movable portion support means (18); a drive means for driving the movable portion; a movable portion locking mechanism (42) for locking a movable portion by limiting the range over which the movable portion can move to be within a predetermined locked movable range; a memory section (36a), within which is stored the movable portion initial position to which the movable portion is moved upon startup of image-blur prevention control; and a control section (36) for moving the movable portion to the initial position and releasing the lock upon startup of control; whereby the predetermined position in the locked movable range is stored as an initial position.

Abstract: The infrared camera apparatus incorporates an infrared lens system that retains high resolution power and yet is successfully reduced in a required volume of infrared lens material that is hard to obtain and expensive, so as to attain a compact and cost-reduced infrared camera apparatus incorporating such an infrared lens system. The infrared lens system has at least a single Fresnel lens piece that has at least one of its opposite sides formed in a Fresnel surface. The Fresnel lens piece is made of a lens material of which transmissivity to light waves of one or more monowavelength(s) within an available wavelength range from 3000 nm to 14000 nm is 35% or higher when it takes a shape of 4-mm thickness uncoated parallel flat plate.

Abstract: The zoom lens includes at least, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; a fourth lens group G4 having negative refractive power; and a fifth lens group G5 having negative refractive power. In the zoom lens, focusing from infinity to a proximity of object is achieved by movement of just fourth lens group toward an image focusing side and is characterized in Satisfaction of expressions below: [Expression 1] 2.1<?rt<3.5??(1) ?1.80<?2t<?0.94??(2) where “?rt” is composite lateral magnification at a telephoto end of lens groups locating closer to the image focusing side than the third lens group at infinity focusing, and “?2t” is lateral magnification at a telephoto end of the second lens group at infinity focusing.

Abstract: An inner focus lens includes 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 negative refractive power. The second lens group is moved along an optical axis, whereby focusing from a focus state for an object at infinity to a focus state for a minimum object distance is performed. A lens group configured by a lens other than a lens that is disposed farthest on the object side is moved in a direction orthogonal to the optical axis to shift an image. The inner focus lens satisfies a conditional expression (1) 0.15?(1??p)×?r?4.50, where ?p is transverse magnification of the orthogonally moved lens group and ?r is composite transverse magnification of a lens group disposed farther on an image side than the orthogonally moved lens group.

Abstract: An inner focus lens includes 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 negative refractive power. The second lens group is moved along the optical axis, whereby focusing from a focus state for an object at infinity to a focus state for a minimum object distance is performed. The inner focus lens satisfies a conditional expression (1) ?29.0?f3/f??5.4, where f3 is a focal length of the third lens group at the focus state for an object at infinity and f is a focal length of the optical system overall at the focus state for an object at infinity.

Abstract: An internal focus lens includes 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 anti-vibration lens formed by a negative lens that is moved in an orthogonal direction with respect to an optical axis to correct image blur consequent to optical system vibration, and further includes an aperture stop disposed farther on an image side of the first lens group than the anti-vibration lens. The second lens group is moved along the optical axis to perform focusing.

Abstract: A zoom lens exhibits a reduction in size, increased magnification, a reduction in variation of angle of view during zooming, and an increased focusing speed, said zoom lens being suitable for an imaging apparatus using a solid-state imaging device such as an interchangeable lens, a digital still camera, a digital video camera, or the like. The zoom lens has, in the lens system, at least: a first negative lens group having negative refractive power; a second negative lens group disposed further towards the image side than the first negative lens group, and which has negative refractive power; and a lens group (A) disposed so as to be adjacent to the image side of the second negative lens group. In the zoom lens, focusing from an infinite distance to a near object is performed by moving only the second negative lens group towards the image side, and prescribed conditions are satisfied.

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: An infrared camera lens that is simple in lens configuration and has lens pieces including only spherical surfaces but no aspheric surfaces. The infrared camera lens includes a foremost or first single spherical lens piece of positive refractivity, a succeeding or second single spherical lens piece of negative refractivity, and a third single spherical lens piece of positive refractivity. At least the second single spherical lens piece of negative refractivity or the third single spherical lens piece of positive refractivity is movable for focusing. The design of the infrared camera lens facilitates and implements an airtight environment within the lens barrel because the foremost or first lens closest to the object stays still during focusing, and the entire length of the lens system is unchanged for focusing.

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 zoom lens includes sequentially from an object side a first lens group having a negative refractive power; an aberture stop; and a second lens group having a positive refractive power. The second lens group is moved along an optical axis toward the object side to zoom from a wide angle edge to a telephoto edge. The first lens group is moved along the optical axis toward en image side to correct image plane variation accompanying zooming. The second lens group includes sequentially from the object side, a positive lens having at least one aspheric surface, and a cemented lens configured by a negative lens, a positive lens, and a negative lens. The zoom lens satisfies a conditional expression (1) 1.8<D2/Z<2.3, where D2 indicates an amount of movement of the second lens group, accompanying zooming from the wide angle edge to the telephoto edge, and Z indicates a zoom ratio.

Abstract: Provided is a zoom lens that has a four-lens configuration and is capable of having a viewing angle of larger than 180°. Provided is an infrared zoom lens that has a long back focus. The present invention comprises a first lens group that has a negative refractive power, and a second lens group that has a positive refractive power. During zooming, the first lens group and the second lens group move on an optical axis, and each of the first lens group and the second lens group is configured of two single lenses.

Abstract: An infrared optical system of two-lens structure comprises a front or first lens of negative refractive power and a rear or second lens of positive refractive power disposed in series relative to an object, the first lens having its concave surface faced toward the imaging plane, the second lens having its convex surface faced toward the object, the infrared optical system meeting the requirements as defined in the following formula 2.1?d/f?11, where d is an axial distance from the surface of the first lens closer to the imaging plane to the surface of the second lens closer to the object, and f is a focal length of the entire optical system.

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 zoom lens includes a first lens group having positive refracting power, a second lens group having negative refracting power, a third lens group having positive refracting power, a fourth lens group having negative refracting power and a fifth lens group having negative refracting power in order from an object side, in which the lens groups move in magnification change from a wide angle end to a telephoto end such that a gap between the first lens group and the second lens group increases and a gap between the second lens group and the third lens group decreases, a negative lens group disposed closer to an image focusing side than a diaphragm among all lens groups is set as a focusing lens group, and the focusing lens group moves toward the image focusing side at focusing from infinity to a close object, and the fifth lens group includes at least a single lens block of a meniscus shape provided with a concave surface at an object side, the single lens block of the meniscus shape has a negative focal distanc