Mitsubishi Kagaku Media Co., Ltd.

Hitachi Maxell, Limited

Pioneer Corporation

Mitsubishi Chemical Corporation

Kenjirou Kiyono

Michikazu Horie

Masae Kubo

Toshinori Sugiyama

Eiji Muramatsu

Takashi Ohno

Yutaka Kurose

Hideyuki Kubo

Hiroshi Nishiwaki

Akio Okamuro

Jun Kanehira

Osamu Shouji

Hidehiro Sasaki

An information recording medium () is provided with (i) a first information recording area wherein a first track for reproducing first information based on a first track pitch is formed by a laser beam, and (ii) a second information recording area wherein a second track for reproducing second information based on a second track pitch different from the first track pitch is formed by a laser beam. The groove shape of the first track is different from the groove shape of the second track.

Information recording medium, information reproducing device and method, and apparatus and method for manufacturing information recording medium

Provided is an optical recording medium comprising a substrate and a reflective layer, a first dielectric layer, a recording layer, a second dielectric layer and a light-transmission layer formed in this order on the substrate. The recording layer is decomposable by heat at a time of recording to achieve recording of the optical recording medium, and the optical recording medium further comprises a third dielectric layer between the second dielectric layer and the light-transmission layer.

Recording medium

Provided is an extremely high-density optical recording medium with excellent jitter characteristics and good recording/reproducing characteristics. An optical recording mediumcomprises a substratewith a guide groove formed therein, a layerwith a light reflection function, a recording layercomprising a dye as a main component with a light absorption function for a wavelength of recording/reproducing light in an unrecorded state, and a cover layercapable of transmitting the recording/reproducing light incident to the recording layer, in the order mentioned; an interlayercontaining at least one element selected from the group consisting of Ta, Nb, V, W, Mo, Cr and Ti, is provided between the layerwith the light reflection function and the recording layer

Optical recording medium

An information recording medium having a recording track wherein the recording track includes a first recording region R, a second recording region Rand a recording region transition section Sx arranged between regions Rand R; a track pitch tp, a groove width wand a groove depth din region R, and a track pitch tp, a groove width wand a groove depth din region Rsatisfy formula (1), (2) and/or (3); the recording region transition section Sx includes a track pitch transition section Stp in which the track pitch changes from tpto tpand a groove shape transition section Sg in which the groove width changes from wto wand/or the groove depth changes from dto d; and the track pitch transition section Stp and the groove shape transition section Sg at least partially overlap to share a region SL.

Optical recording medium having a relation between groove widths, groove depths and track pitches

By use of a substrate which can be stably formed and has a relatively small groove depth, a very high density optical recording medium having good recording/reading characteristics is provided. In an optical recording medium of a surface incidence type, in which a reflective layer, a recording layer containing a dye as a main component and a cover layer are sequentially formed on a substrate having guide grooves formed therein, a guide groove part on a far side from a plane of incidence of a recording/reading light beam on the cover layer is set as a recording groove part, and reflected light intensity in a recorded pit portion formed in the recording groove part is increased by a phase shift and is set higher than reflected light intensity in unrecorded.

Optical recording medium and optical recording method of the same

The main object of the present invention is to provide a recording medium which makes high densification of information possible, particularly a write-once-read-many optical recording medium having good recording signal characteristics to a wide range of recording powers. The present invention is one to accomplish the above object by providing a recording medium having a recording layer, whereby recording is carried out by heating the recording layer, characterized in that the recording layer contains a substance A which decomposes at a temperature which the recording layer reaches when heated for recording, and a substance B which does not undergo a chemical reaction or phase change at a temperature which the recording layer reaches when heated for recording.

An optical recording method to be used for recording at a high data transfer rate length-modulated marks on a recording medium by applying a recording laser beam locally to the recording medium. The recording laser beam has a writing power Pw, is and a bias power Pb. A record mark has a length of nT. With respect to at least two record marks, a pulse dividing number m is at least 2, and with respect to all record marks with m being at least 2, 2.5 is smaller than or equal to n/m, in a case where plural different record mark lengths are to be respectively formed by the same pulse dividing number m.

Optical recording method

The object of the present invention is to provide a technology which has high compatibility and can provide users with conveniences. A new system recording mediumhas a center holeformed on a recording diskand a center holeformed on a center hub, so that the recording mediumcan respond to both an old system driving unit having a centering member coupling with the center holeand a new system driving unithaving a second centering membercoupling with the center hole. Moreover, the old system recording medium is a recording medium providing a recording disk having a center hole incorporated in a cartridge having a center hub, and has a structure where the center hole is coupled both with a first centering memberof the new system driving unitand with the centering member of the old system driving unit.

Cartridge type recording medium and disk-shaped recording medium including a hole for centering each thereof, cartridge, driving unit and driving method

The object of the present invention is to provide a technology which has high compatibility and can provide users with conveniences. A new system recording mediumhas a center holeformed on a recording diskand a center holeformed on a center hubso that the recording mediumcan respond to both an old system driving unit having a centering member coupling with the center holeand a new system driving unithaving a second centering membercoupling with the center holeMoreover, the old system recording medium is a recording medium providing a recording disk having a center hole incorporated in a cartridge having a center hub, and has a structure where the center hole is coupled both with a first centering memberof the new system driving unitand with the centering member of the old system driving unit.

An optical recording medium simultaneously having higher recording characteristics and storage stability than ever, is obtained. An optical recording medium comprising at least a phase change recording layer, a first diffusion preventing layer, a second diffusion preventing layer and a protective layer formed in this order on a substrate, characterized in that the first diffusion preventing layer and the second diffusion preventing layer comprise a non-gas element and nitrogen and/or oxygen as the main components, the non-gas element in each of the first diffusion preventing layer and the second diffusion preventing layer, is the same, and the content (atomic %) of nitrogen and/or oxygen contained in the second diffusion preventing layer, is larger than the content (atomic %) of nitrogen and/or oxygen contained in the first diffusion preventing layer.

Growing community of inventors

Minato-ku, Japan

Kenjirou Kiyono