Tdk Corporation

Yasufumi Takasugi

Hideki Hirata

Masatoshi Nakayama

Kunihiro Ueda

Giichi Shibuya

Kazuki Suzawa

Takashi Namioka

Toshikazu Hosobuchi

Kazuo Fukunaga

Masaharu Nishimatsu

Tsunehiko Ikarashi

Osamu Kohmoto

Hiroshi Sugihara

Yuichi Kubota

Hideki Sasaki

Tsutomu Aoyama

Hiroshi Kawahara

Hitoshi Azegami

Osamu Inoue

Tadayoshi Iijima

Takayoshi Kuwajima

Kiminori Tamai

Akira Saitoh

Tsutomu Kotani

Kazuhiro Kuroda

Masahide Kohno

Yousuke Hitomi

Yuko Motegi

Naoyuki Nagashima

Fuminori Tokuda

Yasushi Ishikawa

It is an object of the present invention is to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is formed with periodical undulation in the circumferential direction thereof. The apparatus for discriminating an optical recording medium according to the present invention includes a first electrode, a second electrode, an alternate current signal generation circuitfor applying an alternate current A to the first electrode, a detection circuitfor detecting a level of an alternate current B appearing at the second electrode, and a control circuitfor controlling the operations of the alternate current signal generation circuitand the detection circuit

Apparatus for discriminating optical recording medium and method for discriminating optical recording medium

The present invention provides a method and an apparatus for discriminating the type of an optical recording medium and the number of recording layers in the medium. The apparatus includes a first electrode and a second electrode placed in the vicinity of a light transmission layer of the recording medium, an alternating current signal generation circuit for applying an alternating current A to the first electrode, a detection circuit for detecting the level of an alternating current B appearing at the second electrode, and a control circuit for controlling the operations of the alternating current signal generation circuit and the detection circuit, and a table provided in the control circuit.

It is an object of the present invention to provide an apparatus for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is warped and formed with periodical undulation in the circumferential direction thereof. The apparatusfor discriminating an optical recording medium according to the present invention includes a first electrodea second electrodea third electrodea fourth electrodean alternating current signal generation circuitfor applying an alternating current signal A to the first electrodeand the third electrodea detection circuitfor detecting the level of an alternating current signal Bappearing at the second electrodeand the level of an alternating current signal Bappearing at the fourth electrodea supporting mechanismfor supporting the first electrodeand the second electrodea supporting mechanismfor supporting the third electrodeand the fourth electrodea driving mechanismfor vertically moving the supporting mechanisma driving mechanismfor vertically moving the supporting mechanismand a control circuitfor controlling the operations of the alternating current signal generation circuitthe detection circuitthe driving mechanismand the driving mechanismand a tableis provided in the control circuit

It is an object of the present invention to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is warped. The apparatus for discriminating an optical recording medium according to the present invention includes a first electrode, a second electrode, an alternating current signal generation circuitfor applying an alternating current signal A to the first electrode, a detection circuitfor detecting the level of an alternating current signal B appearing at the second electrode, a supporting mechanismfor supporting the first electrodeand the second electrode, a driving mechanismfor vertically moving the supporting mechanism, and a control circuitfor controlling the operations of the alternating current signal generation circuitand the detection circuitand the driving mechanism

An object of the present invention is to provide functional films which can exhibit a variety of functions using functional fine particles, in particular, a transparent conductive film having a low resistance value using conductive fine particles. The functional film of the present invention is a functional film comprising a support and a functional layer on at least one surface of the support, wherein the above functional layer contains functional fine particles, and a ratio (&sgr;1/&sgr;2) between a dispersion value (&sgr;2) obtainable from the alignment of the functional fine particles at the front surface of the functional layer and a dispersion value (&sgr;1) obtainable from the alignment of the functional fine particles at the opposite surface of the functional layer is from 1.2 to 1.85. Thereby, a sufficient contact of the functional fine particles is effected in the functional layer and the strength of the functional layer and the adhesiveness between the functional layer and the support become large, so that a transparent conductive film wherein conductive fine particles are used as the functional fine particles, for example, has a low electric resistance.

Functional film having specific surface dispersion ratio

Polyoxymethylene articles having a surface printable with an ultraviolet-curing ink are obtained by molding a polyoxymethylene and treating the molded article by ultraviolet irradiation, corona discharge, or electron-beam radiation until the surface has an X-ray photoelectron spectrum in which the ratio of the �C--O!.sub.n bond peak at 302 eV to the C--C bond peak at 305 eV, i.e., the �C--O!.sub.n bond peak/C--C bond peak ratio, is at least 2.5.

Polyoxymethylene articles having printable surface method of imparting

A magnetic layer is provided on a nonmagnetic base with a non-ferromagnetic layer interposed between them. Non-ferromagnetic particulate iron oxide is incorporated in the non-ferromagnetic layer. In addition to, or in place of, this iron oxide, non-structural carbon having a mean particle diameter of 10 to 60 nm, a specific surface area of 150 m2/g as measured by the BET method and a DBP oil absorption of 100 ml/100 g or less may be used. This makes it possible to achieve a magnetic recording medium having excellent surface properties and good-enough electromagnetic transducing characteristics.

Magnetic recording medium

In a magnetic recording medium comprising on a non-magnetic substrate a magnetic layer obtained by dispersing ferromagnetic powder in an electron beam-curable resin followed by electron beam curing or a backcoat layer obtained by curing an electron beam-curable resin with electron beams, a combination of an electron beam-curable vinyl chloride resin having a sulfur-containing polar group and an electron beam-curable urethane resin having a phosphorus-containing polar group is used as the electron beam-curable resin. This results in improvements in dispersibility, surface smoothness, and electromagnetic characteristics, as well as a lowering of error rate in high density digital recording. Storage property is good.

In a magnetic recording medium comprising a substrate, a ferromagnetic metal thin film formed on the substrate, and a topcoat formed on the thin film, the topcoat comprises a plasma-polymerized film containing carbon and hydrogen with the atomic ratio of carbon to hydrogen being from 1 to 6, and an organic material film deposited on the plasma-polymerized film by evaporation.

In a magnetic recording medium comprising a substrate, a ferromagnetic metal thin film formed on the substrate, and a topcoat formed on the thin film, the topcoat is a plasma-polymerized film containing carbon and hydrogen in an atomic ratio of C/H of from 1 to 6, and having a thickness of 10 to 40 angstroms and a contact angle with water in the range of from 60.degree. to 130.degree..

A magnetic recording medium is provided comprising a non-magnetic substrate, a magnetic metal layer of continuous thin film type deposited on the substrate, and a topcoat film on the magnetic layer. The topcoat film is formed by sputtering or ion plating a fluorocarbon resin so that it consists essentially of carbon and fluorine, and fluorine atoms of the topcoat film are chemically combined with metal atoms of the magnetic layer in proximity to the interface.

In a magnetic recording medium comprising a substrate and a magnetic layer thereon, the magnetic layer is formed by coating a composition of a binder, preferably radiation-curable binder and a needle magnetic material, passing the coating through a magnetic field to forcedly re-orient the magnetic particles to form pores having an average pore area of 6.times.10.sup.-5 to 7.times.10.sup.-1 .mu.m.sup.2, and curing the coating, thereby minimizing output fluctuation and improving durability. Preferably lubricant is present in the pores.

Magnetic recording medium and preparation

A magnetic recording medium comprising a substrate, a ferromagnetic metal thin film on the substrate, and a topcoat on the thin film exhibits improved strength and durability when the topcoat is comprised of a plasma-polymerized film prepared by activating a gaseous hydrocarbon monomer or a mixture thereof with a carrier gas into a plasma under specific conditions. The plasma-polymerized film consists of carbon and hydrogen in an atomic ratio of C/H of from 1:1 to 6:1 and has a thickness of 3 to 15 .ANG. and a contact angle with water in the range from 60.degree. to 120.degree.. An organic coating may be present on the plasma-polymerized film.

A magnetic recording medium for use in video and other applications is presented which comprises a substrate, a continuous thin magnetic layer of cobalt and at least one selected from nickel, chromium, and oxygen, preferably obliquely evaporated on the substrate, and a topcoat formed over the magnetic layer and made of a phosphate compound having the formula: ##STR1## where R is selected from the group consisting of substituted or unsubstituted alkyl radicals having 10 to 22 carbon atoms which may be saturated or have an unsaturated double bond in their backbone, and substituted or unsubstituted aryl, alkaryl, aralkyl and alkylarylalkyl radicals having 6 to 20 carbon atoms, and

A magnetic recording medium for use in video and other applications is presented which comprises a substrate, a continuous thin magnetic layer of cobalt and at least one selected from nickel, chromium, and oxygen, preferably obliquely evaporated on the substrate, and a topcoat formed over the magnetic layer and consisting of a monoalkylamine in which the alkyl contains 10 to 22 carbon atoms.

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Tokyo, Japan

Yasufumi Takasugi