Totoku Electric Co., Ltd

Emit Seiko Co., Ltd.

Fdk Corporation

Takeyasu Nakayama

Kazuhiko Terao

Tohru Mizuhashi

Toshiya Kubo

Nobutoshi Takeda

Yoshihiro Matsuoka

Hidetoku Iida

Satoshi Yamazaki

Hiroto Imamura

Jiro Horigome

Takashi Kato

Masanori Nonomura

Satoshi Takehana

Ikuo Maeda

Akihiro Masuda

To provide a coaxial cable with a favorable appearance and excellent processability. The above-described problem is solved by a coaxial cable comprising a center conductor (), an insulator () provided on an outer periphery of the center conductor (), an external conductor () provided on an outer periphery of the insulator (), and an outer coated body () covering the external conductor (). The external conductor () is constituted by a lateral winding shield () provided with metal fine wires laterally wound on the outer periphery of the insulator (), and a metal resin tape () wound in a layer on the lateral winding shield () with a metal layer side being on an inside. The outer coated body () is constituted by a resin tape () wound on the metal resin tape (), and an extruded sheath () covering the resin tape (). Given T1 as a thickness of the metal resin tape () and T2 as a thickness of the resin tape (), T2/T1 is within a range from 0.180 to 0.800.

Coaxial cable

A coaxial cableincludes a hollow-core-bodyhaving an integral structure of thermoplastic resin including an inner annular portionthat insulation-coats an inner conductor, a plurality of rib portionsthat radially extend from the inner annular portion, and an outer annular portionthat is connected to outer ends of the rib portions; three or more gap portionssurrounded by the inner annular portion, the rib portions, and the outer annular portion; and outer side reinforcing portionsbeing formed on both sides of an outer end in the rib portion, in which a size ratio of a minimum value Wof a rib width in the rib portionand a maximum value Wof the rib width in the rib portionis within a range of 1:1.6 to 1:3.0.

A twin-core ferrule structure is provided which is miniaturized in size, facilitated for accurate positioning the optical axes of two optical fibers, and improved both in degree of freedom of determining a shape and in high-volume productivity. The twin-core ferrule 21 comprises a cylindrical sleeve 22 having a first optical fiber element fitting hole 23 provided in the front region of a circular cylindrical body thereof to extend along the center axis of the same, a second optical fiber element fitting hole 24 provided in the same to extend eccentric to the center axis of the circular cylindrical body and in parallel with the first optical fiber element fitting hole 23, and an eccentric cylindrical hole 25 provided in the rear region of the circular cylindrical body to extend with the center axis coinciding with the center line between the first and second optical fiber element fitting holes 23 and 24, into which an optical fiber core is fitted, wherein the cylindrical sleeve 22 is monolithically formed by injection molding of a metal material.

Twin-core ferrule structure for an optical connector

The end face of an optical fiber assembly consisting of an optical fiber s and a ferrule f is polished to form a conical surface with oblique faces Fp1 and Fp2 such that, central axis Ap of the conical surface makes an inclination of 8.degree. with respect to the optical axis L of the optical fiber s, top Ft of the conical surface coincides with the optical axis L of the optical fiber s, and has a taper angle of 2.degree.. Thereafter, the optical fiber assembly is further polished to form an oblique convex spherical surface at the end face such that, the central axis of the oblique convex spherical surface makes an inclination of 8.degree. with respect to the optical axis L of the optical fiber s. Due to this, insertion loss and light reflected back to the source is stabilized and minimized.

Method for manufacturing optical fiber assembly with polished end-face,

End face of a ferrule 100 is polished to form a conical surface 3 such that, central axis Ap of said conical surface 3 makes an inclination of 8.degree. with respect to central axis L of optical fiber insertion hole 4, top 3t of said conical surface 3 coincides with said central axis L and has a taper angle of 2.degree.. Because of this, while polishing an end of a optical fiber inserted and fixed inside said optical fiber insertion hole 4, a well balanced oblique spherical surface can be formed and the non-coincidence of the center of said oblique convex surface with the point where said oblique convex surface intersect with the optical axis of said optical fiber can be prevented.

End-face polished ferrule and its method of manufacture

An optical fiber assembly is disclosed, which permits reduction of light reflection, suppression of reflected return light and reduction of connection loss and also facilitates its manufacture. The optical fiber assembly 10 comprises an optical fiber 18 and a ferrule 12 with an end taper and mounted on an end portion of the optical fiber. The end face of the optical fiber 18 and the end face of the ferrule 12 are constituted by a convex spherical surface S1 with the center P0 thereof at a position spaced apart from the center line L0 of the optical fiber 18. The radial line L1 passing through the center P1 of the optical fiber and the center P0 makes an angle .theta.' of 6 to 12 degrees with respect to the center line L0, the radius of curvature is 50 to 70 mm, and the symmetricity angle .DELTA..theta. is 0.1 degree or less.

Growing community of inventors

Nagano, Japan

Takeyasu Nakayama