Sanyo Electric Co., Ltd.

Yutaka Ueta

Takahiro Ogawa

Youhei Nakagawa

Kiyotaka Ito

Satoru Ota

Atsushi Inoue

Kazuhiko Koga

Hiroyuki Ohno

Hiroyuki Okuda

Kousou Ishihara

Atsushi Furuzawa

Takao Yamano

Yuma Aoi

Yoshifumi Fukumoto

Kazuhiro Koga

Kiyotaka Itou

Ai Takumi

Toshinori Urano

In an imaging lens, one compound lens and two single lenses are arranged in a lens barrel. On the light output side of the lens barrel, a filter is arranged with a distance from lens barrel. With a further distance from the filter, an imaging element is arranged. In the compound lens, a resin lens is bonded to a base member lens, having an output surface center of the resin lens displaced by a prescribed amount relative to an output surface center of the base member lens, so that a transmission decentration amount attributed to the base member lens, not including the resin lens, and the single lenses is cancelled by a transmission decentration amount by the resin lens when taken as a whole lens system. Thus, the imaging lens capable of suppressing reduction in resolving power due to transmission decentration of the lenses is obtained.

Imaging lens, manufacturing method thereof, and compound lens

A composite lens of the present invention has a base lens and a resin lens placed on the base lens. The resin lens has, in an area outside an optically effective diameter, a first surface, a second surface that is adjacent to the first surface, and a third surface that is adjacent to the second surface in sequence from an optical axis to an outer circumference. The first surface has an inclined surface that becomes higher from the outer circumference toward the optical axis, and the inclined surface is connected to the second surface. The second surface has a plane that is substantially perpendicular to the optical axis, and the substantially perpendicular plane is connected to the first plane. The third surface has an inclined surface that becomes lower from an inner circumference toward the outer circumference.

Composite lens

An optical lens includes a lens effective portion, an inclined portion and a flange portion. The lens effective portion has, on a first side, a lens face with a small radius of curvature and also has, on a second side, a lens face with a large radius of curvature. The inclined portion has, on the first side, an inclined face inclined outwardly from the first side to the second side. The flange portion has, on the second side, a reference face protruding longer than the lens face with the large radius of curvature on the second side. Thus, it is possible to obtain an optical lens which is less susceptible to deformation or chipping and suppresses transmission eccentricity, a compound lens and a method for producing the same, as well as a cemented lens and a method for producing the same.

Optical lens, compound lens and method for producing the same, as well as cemented lens and method for producing the same

A magnetic head comprises a first abutting segment formed with a winding groove having an open side, and a second abutting segment opposed to the open side of the groove and joined to the first segment. The first abutting segment comprises a first core segment having the groove, and gap spacers and second ferromagnetic thin films formed on the surface thereof opposed to the second segment and positioned above and below the groove. The first core segment comprises a core segment member made of a ferromagnetic material, formed with the groove and having a first ferromagnetic thin film which is formed on the surface thereof opposed to the second abutting segment and which is positioned toward the face of the head to be opposed to recording media. The second abutting segment has a face to be opposed to the recording medium and formed by a nonmagnetic material.

Magnetic head for magnetic recording and reproduction

A floating type composite magnetic head includes a head core fixed to a slider formed of nonmagnetic material. In the head core, a pair of magnetic core halves are abutted against each other with nonmagnetic material such as SiO.sub.2 or the like interposed therebetween. The first and second magnetic core half members have first and second gap forming surfaces to be abutted against each other to define a magnetic gap (g), respectively. A first groove is formed on the second gap forming surface. A glass layer is formed in the first groove. A first thin film including a ferromagnetic metal thin film is selectively formed on the first gap forming surface. A second thin film including a ferromagnetic metal thin film is selectively formed on the second gap forming surface so that at least a portion except the surface of the glass layer in the second gap forming surface is exposed. A second groove is formed on the exposed second gap forming surface adjacent to the first groove. The first and second magnetic core half members are abutted and bonded with glass so that the first and second gap forming surfaces face each other so that the first and second thin films are abutted with SiO.sub.2 or the like interposed therebetween to define a magnetic gap (g). Causes of occurrence and an increase of false gaps are suppressed and a decrease in manufacturing yield due to separation of thin films or the like can be prevented.

Method of manufacturing floating type magnetic head

A floating-type magnetic head comprising a slider and a core chip secured thereto. The core chip comprises a pair of core segments joined together with a gap spacer and a thin ferromagnetic metal film which are formed at the joint only over a portion of the entire area of the joint which portion terminates at the face of the core chip to be opposed to magnetic recording media. The two core segments area bonded to each other with glass present over the remaining portion of the joint area. In producing the magnetic head, the core chip is prepared by fabricating a core block comprising a pair of base plates joined together and strips of thin ferromagnetic metal film and gap spacer provided at the joint, and machining the core block.

A process for producing magnetic heads of the floating type

Growing community of inventors

Yao, Japan

Yutaka Ueta