Taiyo Yuden Co., Ltd.

Daizo Yokoyama

Kenichiro Nogi

Fuyuki Miyazawa

Katsuhiro Oyama

Hidemi Iwao

Takeo Tsuzuki

Takuo Kodaira

Hidenori Somei

Koji Taketomi

In a common mode choke coil having a magnetic core, a decrease in peak value of a common mode impedance in a vicinity of its resonance frequency is suppressed. A common mode choke coil includes a non-magnetic layer, a first magnetic layer formed on a top surface of the non-magnetic layer, a second magnetic layer formed on a bottom surface of the non-magnetic layer, a magnetic core provided between the first magnetic layer and the second magnetic layer so that its axis extends in a top-bottom direction, a first coil conductor embedded in the non-magnetic layer and wound around the magnetic core, a second coil conductor embedded in the non-magnetic layer and wound around the magnetic core, and a first magnetic gap provided between a top surface of the magnetic core and a bottom surface of the first magnetic layer. The magnetic core is made of a ferrite material.

Common mode choke coil

Provided is an optical information recording medium employing an In-Groove recording system, and having a preferable recording characteristic with a high modulation degree and low jitter characteristics. The medium is comprised of a circular-disk shaped substratehaving a through hole at a center portion thereof and a helical guide grooveon one surface thereof; a reflective layerformed on the guide grooveof the substrate; a recording layerformed on the reflective layerand composed of an organic material including a dye; a protection layerprovided on the recording layer; and a light-transmissive layerformed on the protection layer. The recording layerincludes an organic dye which is an azo metal complex compound having a structure represented by (Chemical formula 1) and a functional group represented by (Chemical formula 2).

Dye for optical information recording medium and optical information recording medium

There is proposed an optical disk recording method that can prevent degradation of recording quality due to occurrence of thermal interference, and an optical disk recording reproduction device used in this recording method. The recording method has a step of executing a test record on an output proofing area of the optical diskwhile a spot diameter of the recording laser beam is varied, and deriving the relationship between the spot diameter and a characteristic value representing recording quality, a step of deriving a permissible range of a variation amount of the spot diameter on the basis of the derived relationship between the spot diameter and the characteristic value representing the recording quality; a step of irradiating a record region of the optical disk with the recording laser beam to detect spherical aberration while executing recording; and a step of executing aberration correction, in case the spherical aberration occurs, such that a variation amount of the spot diameter falls into the derived permissible range.

Recording method for optical disk and optical disk recording reproduction device

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Tokyo, Japan

Daizo Yokoyama