Hitachi Cable, Inc.

Hitachi, Ltd.

Seiko Instruments Inc

Hitachi Cable Co., Ltd.

Hisao Iitsuka

Hiroshi Kajioka

Toshiya Yuhara

Kiyohiko Tanno

Tetsuo Kumazawa

Kazuyuki Fukuda

Tatsuya Kumagai

Makoto Shimaoka

Hideo Hirane

Wataru Ohnuki

Kentaro Yagi

Toshiyuki Tetsu

Tomohiro Murakami

Mamoru Ichimura

The orientation of the rotating direction of an optical fiber in an optical fiber array takes the positional axial displacement into consideration. In a method of aligning the orientation of optical fibers, or the axial displacement in an optical fiber array having a plurality of optical fibers, and an optical fiber holding member, an enlarged image of the optical fiber is obtained for each of the optical fibers using an image pick-up means. Then, a distribution of the characterized image corresponding to the positions in the radial direction of the image of the optical fiber are obtained from the enlarged image. From the distribution of the characterized image, the orientation of the rotational direction to the center of the optical fiber, or the positional axial displacement of the core center, is measured. Based on the measured result, the orientation of the rotational direction, or the positional axial displacement to the holding member of the optical fiber, is aligned with an optical fiber rotating mechanism.

Method of aligning optical fiber to optical fiber or optical fiber to

A connecting structure of an optical fiber to an optical waveguide includes a circular cylindrical holder having a bore with a circular cross-section communicating one end thereof to the other. The protecting layer removal end of the optical fiber is inserted into the bore. An end plane of the protecting layer removal end and a side plane of the holder are co-planar to be connected to an end surface of an optical waveguide.

Connecting structure of optical fiber to optical waveguide

In an optical fiber gyro for detecting a rotation angular velocity by Sagnac phase difference of light signals propagated through an optical fiber sensing loop, no polarizer is used, and a light source having a difference in attenuation or amplification factor between two orthogonally polarized lights is used. Alternatively, a light source is optically coupled to an optical coupler for supplying two divided light signals to the sensing loop and receiving the two light signals propagated through sensing loop by an optical fiber of a predetermined length which is set to meet a relation in which a distance difference determined by the predetermined length and a phase difference of two orthogonally polarized lights propagated through the optical fiber is greater than an interference distance of the light source.

Optical fiber gyro

A driving circuit for a light emitting diode array, which is divided into a plurality of drivers for every driving output and so constructed that the control of the sum of the currents flowing therethrough is set by selecting one or a plurality of the divided drivers by using digital signals '1' and '0'.

Driving circuit for a light emitting diode array

Growing community of inventors

Hitachi, Japan

Hisao Iitsuka