An imaging lens substantially consists of a first lens-group, a stop and a second lens-group in this order from an object-side. The first lens-group substantially consists of three or less lenses including at least one negative lens and a positive lens. The second lens-group substantially consists of a 21st lens-group and a 22nd lens-group in this order from the object-side. The 21st lens-group substantially consists of three or less lenses and has positive refractive-power. The 22nd lens-group substantially consists of two lenses of a negative lens and a positive lens in this order from the object-side. Predetermined conditional formulas about distance on an optical-axis from a most-object-side lens surface in an entire system to an image-plane, maximum image height, distance on the optical-axis from a most-object-side lens surface in the first lens-group to a most-image-side lens surface in the second lens-group, and focal-length of the entire system are satisfied.

Imaging lens and imaging apparatus

An optical scanner includes a light source, an optical coupler, an optical line image unit, a deflector, and an optical scanning unit. The optical scanning unit includes scanning lenses that guide the beams to a surface to be scanned. A surface on the deflector side of the scanning lens closest to a deflection reflecting surface has a negative power in a vertical scanning direction, and is a special toric surface in which a radius of curvature in a vertical scanning changes from an optical axis of the lens surface toward a periphery of the horizontal scanning direction. An F number of the beams toward the surface to be scanned of the scanning lens in the vertical scanning direction is larger in a peripheral part than in a central part in an effective scanning width.

Optical scanner and image forming apparatus

An object of the present invention is to provide a low-cost, miniature, wide-angle high-zoom-ratio zoom lens that has high imaging performance, and an imaging apparatus equipped with the zoom lens. To achieve the object, a zoom lens including a first lens group having positive refracting power, a second lens group having negative refracting power and a third lens group having positive refracting power in order from an object side in which a lens group P having positive refracting power is arranged closer to an image plane side than the third lens group.

Zoom lens and imaging apparatus

A storage system is provided with a memory region, a cache memory region, and a processor. The memory region stores the time relation information that indicates a time relationship of a data element that has been stored into the cache memory region and that is to be written to the logical region and a snapshot acquisition point of time to the primary volume. The processor judges whether or not the data element that has been stored into the cache memory region is a snapshot configuration element based on the time relation information for the data element that is to be written to a logical region of a write destination that conforms to the write request that specifies the primary volume and that has been stored into the cache memory region. In the case in which the result of the judgment is positive, the processor saves the data element to the secondary volume for holding a snapshot image in which the snapshot configuration element is a configuration element, and a data element of a write target is then stored into the cache memory region.

Storage system and storage control method

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 ν12<26 (n12 and ν12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Zoom lens system, imaging device and camera

PROBLEM TO BE SOLVED: To provide an imaging lens composed of five lenses, which satisfactorily corrects a spherical aberration and an astigmatic aberration even when the entire lens length is shortened in accordance with the compact size of a lens unit, and which suppresses image quality degradation resulting from an eccentricity error, and to provide an imaging optical device and a digital apparatus. SOLUTION: The imaging lens LN includes, in order from an object side, a first lens L1 of positive refractive power, the convex face of which is oriented on the object side, a second lens L2, the concave face of which is oriented in the direction of the object side, a third lens L3 of positive refractive power, the fourth lens L4 of positive or negative refractive power, and a fifth lens L5 of positive or negative refractive power. Each of the first and third lenses L1 and L3 has at least one aspherical face, and satisfies the following conditional expression: 0.4 COPYRIGHT: (C)2011,JPO&INPIT

Imaging lens, imaging optical device and digital apparatus

PROBLEM TO BE SOLVED: To provide a high-definition imaging optical system capable of completely correcting chromatic aberration while achieving complete miniaturization with constitution of three lenses. SOLUTION: The imaging optical system 10 is equipped with: a first lens 11 having positive optical power; a second lens 12 having positive optical power; and a third lens 13 having negative optical power in order from an object side. In the imaging optical system 10, a diffractive surface is formed on at least one lens surface of the lens surfaces 11a and 11b of the first lens 11 and the lens surfaces 12a and 12b of the second lens 12, which are positive lenses. The imaging optical system 10 is constituted to satisfy a conditional expression; 0.2<P L /P<2.0 when assuming that power by the refraction of the lens including the diffractive surface is P L and power by the refraction and the diffraction of the entire system of the imaging optical system 10 is P. COPYRIGHT: (C)2007,JPO&INPIT

Imaging optical system, imaging lens device, and digital equipment

PROBLEM TO BE SOLVED: To provide a compact variable power optical system which has high optical performance and can be mounted on a cellular phone and a personal digital assistant, while restraining rise in cost rise, and to provide an imaging lens device and digital equipment on which the imaging lens device is mounted. SOLUTION: The variable power optical system has a 1st lens group having negative optical power as a whole and 2nd and 3rd lens groups having positive optical power as a whole in order from an object side, and they are all constituted to move in an optical axis direction at varying of power. The 1st lens group is constituted of a biconcave lens, having negative optical power and a positive meniscus lens convex to the object side, in this order from the object side, and the 2nd lens group is constituted of a doublet constituted, by arranging and bonding a biconvex lens having positive optical power and a biconcave lens having negative optical power in order from the object side; then the 3rd lens group is constituted of a biconvex lens having positive optical power. The 1st and the 5th lenses are both-surface aspherical lenses formed of resin, and the 3rd and the 4th lenses are one-surface aspherical lenses. COPYRIGHT: (C)2006,JPO&NCIPI

Variable power optical system, imaging lens device and digital equipment

PROBLEM TO BE SOLVED: To provide a super wide-angle optical system having a wide angle of view in a prescribed direction, while realizing compact sizing and restraint in cost rise, and to provide an imaging apparatus, an on-vehicle camera and digital equipment. SOLUTION: A front group (Gr1) is constituted of a negative lens, a negative lens and a positive lens, in this order from the object side, and a rear group (Gr2) is constituted of a doublet comprising a negative lens and a positive lens, and a positive lens, in this order from the object side. The 2nd lens and the 6th lens are manufactured of resin (plastic). Then, both surfaces r3 and r4 of the 2nd lens and the lens surface r12 of the 6th lens on an image side are made anamorphic surfaces, and the lens surface r11 of the 6th lens on the object side is made into an aspherical surface. COPYRIGHT: (C)2006,JPO&NCIPI

Super wide angle optical system, imaging apparatus, on-vehicle camera and digital equipment

An image-capturing lens comprises in order from the object side a positive first lens, a stop, a positive second lens, a negative third lens, a positive fourth lens, and a negative fifth lens, satisfies the conditional expression of 0 < f1/f2 < 1.26 (where f1 is the focal length of the first lens and f2 is the focal length of the second lens), and forms an image of an object on the image-capturing surface of an image-capturing element.

Keiji Matsuzaka

Papers

Imaging lens, imaging optical device and digital apparatus

Imaging optical system, imaging lens device, and digital equipment

Variable power optical system, imaging lens device and digital equipment

Super wide angle optical system, imaging apparatus, on-vehicle camera and digital equipment

Image-capturing lens