Tdk Corporation

Hiroshi Take

Narutoshi Fukuzawa

Hiroshi Kawahara

Takashi Horai

Akira Furuya

Naoki Hayashida

Kazushi Tanaka

Hiroyuki Arioka

Hidetake Itoh

Motohiro Inoue

Keisuke Takasugi

Toshiyuki Yoshizawa

Masahiro Miyazaki

Syuji Tsukamoto

Masaomi Ishikura

Shuji Tsukamoto

To provide a thin film capacitor having a device structure for suppressing peeling between an insulating film and a substrate. A thin film capacitorhas a laminate structure that is formed by laminating a lower electrode, a dielectric film, and an upper electrodein sequence on a substrate. An adhesion layeris formed on a side surface of the lower electrodevia the dielectric film, and an insulating filmin contact with the adhesion layercovers the laminate structure. According to this device structure, the adhesion layerhaving excellent adhesiveness to the insulating filmis disposed between the insulating filmand the dielectric film, so that peeling of the insulating filmcan be suppressed.

Thin film capacitor

The present invention provides an electronic component which is capable of effectively suppressing the characteristic deterioration of the passive element portion. An electronic component comprises a ceramic substrate, a passive element portion on the substrate, an insulator layer which is provided over the passive element portion and comprises a through-hole, a lead terminal which is fitted in the through-hole of the insulator layer and electrically connected to the passive element portion, and an external connection terminal which is electrically connected to the lead terminal. The insulator layer comprises a first face on the side of the passive element portion, a second face on the side opposite the passive element portion, and a third face which connects the first face and the second face and constitutes the peripheral face of the insulator layer, the external connection terminal is in contact with the lead terminal and the second face and the third face of the insulator layer. In a cross-section of the through-hole in a thickness direction of the substrate, a boundary line between the internal surface of the through-hole and the lead terminal is inclined in a direction moving away from a region of the third face with which the external connection terminal is in contact with an end of the boundary line on the side of the first face being taken as a fixed point.

Electronic component

An optical information medium includes a light-transmitting supporting substrate, an information recording layer on one surface of the supporting substrate, a protective layer on the information recording layer, and a light-transmitting hard coat layer on an other surface of the supporting substrate. The medium is configured to have a recording/reproducing beam incident into the information recording layer through the hard coat later and the supporting substrate.

Method for evaluating optical information medium and optical information medium

A simple method for evaluating an optical information medium by judging quantitatively and reproducibly the surface quality of the optical information medium by the use of an artificial fingerprint liquid as an evaluation dispersion liquid, is provided. An optical information medium having a remarkably excellent anti-staining property of the surface which is on the incident side of recording/reproducing beam is provided. A method for evaluating an optical information medium, comprising: adhering an artificial fingerprint liquid containing a fine-particle-form substance and a dispersion medium capable of dispersing the fine-particle-form substance onto the surface of the optical information medium which is on the incident side of a recording/reproducing beam; observing the state of the artificial fingerprint liquid droplets adhered to the surface; and judging the quality of the medium surface. For example, the quality of the medium surface is judged by: (1) Measurement of the area ratio of the surface occupied with the artificial fingerprint liquid droplets adhered per unit area of the surface; (2) Measurement of the diameter of the artificial fingerprint liquid droplets adhered to the surface; (3) Measurement of the number of the artificial fingerprint liquid droplets adhered per unit area of the surface; or (4) Measurement of the degree of roundness of the artificial fingerprint liquid droplets adhered to the surface.

The present invention provides an optical recording medium that includes a recording layer composed mainly of an organic compound and can utilize blue-violet semiconductor laser light (390 to 420 nm in wavelength) as recording/reproducing laser light. The present invention also provides an optical recording/reproducing method using the optical recording medium. The optical recording mediumcomprises at least a supporting substrate; a recording layeron the supporting substrate, the recording layercontaining an organic compound as a major component; and a light-transmitting layeron the recording layer, the light-transmitting layerbeing capable of transmitting laser light with a wavelength of 390 to 420 nm for recording and reproducing information. The organic compound in the recording layerincludes a trimethine cyanine dye that has the minimum value nof its refractive index n (real part of the complex refractive index) within the range of 370 to 425 nm and has a refractive index n of 1.2 or lower with respect to the wavelength of the recording/reproducing laser light. The organic compound, when absorbing the laser light, melts or degrades to bring about a change in the refractive index, thereby effecting recording of the information.

Optical recording medium and optical recording/reproducing method

It is an object of the present invention to provide a multilevel optical recording medium in which influence of variation in characteristics of a recording layer in a plane of the recording layer on reproduced data can be corrected The multilevel optical recording medium according to the present invention includes at least a recording layerand is constituted so that data can be recorded therein in a multilevel manner by controlling a state of the recording layeramong multiple stages and the multilevel optical recording medium according to the present invention is characterized in that a plurality of calibration signals are stored in the recording layerAccording to the thus constituted multilevel optical recording medium, since an optical data recording and reproducing apparatus can detect and correct for the variation in characteristics of the recording layerin the plane thereof, even in the case where variation in characteristics of the recording layerin the plane thereof is present, data recorded in the multilevel optical recording medium in a multilevel manner can be read in a desired manner.

Multilevel optical recording medium with calibration signals

A reproduction method for a multi-level optical recording medium according to the present invention rotates an optical recording medium, on which recording data has been recorded according to a multi-level recording method which sets several levels for light reflectivity of virtual recording cells, emits a reproduction laser beam towards the optical recording medium, and reproduces the recording data based on an electric signal generated in accordance with a received level of reflected light, the method setting the emission power of the reproduction laser beam in a range of 1.0 mW to 2.5 mW inclusive when the optical recording medium is rotated at a linear velocity in a range of 9 m/s to 25 m/s inclusive. By doing so, it is possible to improve the read accuracy for recording data while suppressing the reproduction deterioration of the optical recording medium to a level where deterioration effectively does not occur.

Multi-level optical recording medium reproducing method and reproducing device

An optical disc is includes a recording layer, a reflective layer, and a protective layer provided, in that order, on one surface of a light-transmissive substrate and a hard coating layer having a thickness in the range of 1 to 5 &#x3bc;m on the other surface of the substrate. The hard coating layer is formed by applying and curing a solution comprising a hard coating agent containing colloidal silica and a UV-curable acrylic resin and a solvent containing butyl acetate as a principal constituent. The hard coating layer contains 90 mg/cmor less of residual solvent.

Optical disc and method for manufacturing the same

An optical disc is includes a recording layer, a reflective layer, and a protective layer provided, in that order, on one surface of a light-transmissive substrate and a hard coating layer having a thickness in the range of 1 to 5 &#x3bc;m on the other surface of the substrate. The hard coating layer is formed by applying and curing a solution comprising a hard coating agent containing colloidal silica and a UV-curable acrylic resin and a solvent containing propylene glycol monomethyl ether as a principal constituent. The hard coating layer contains 40 mg/cmor less of residual solvent.

An optical disc is includes a recording layer, a reflective layer, and a protective layer provided, in that order, on one surface of a light-transmissive substrate and a hard coating layer having a thickness in the range of 1 to 5 &#x3bc;m on the other surface of the substrate. The hard coating layer is formed by applying and curing a solution comprising a hard coating agent containing colloidal silica and a UV-curable acrylic resin and a solvent containing propylene glycol monomethyl ether acetate as a principal constituent. The hard coating layer contains 110 mg/cmor less of residual solvent.

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Tokyo, Japan

Hiroshi Take