Ricoh Company, Ltd.

Yasuhide Fujiwara

Yasuo Sawada

Yuzuru Kudoh

Shigeru Fujita

Hiroyuki Endo

Akihiko Shimizu

Hiroya Abe

Koubun Sakagami

Hisamitsu Kamezaki

Hiroyuki Miyata

Takaaki Konno

Atsuo Hirai

Asae Kamata

Yasuomi Mikami

Kengo Fujie

A fixing belt includes a polyimide layer. The polyimide layer includes polyimide and an aprotic solvent. The solvent has a boiling point not lower than 230&#xb0; C. and a solubility parameter not less than 24.5 (J/cm)and not greater than 30.7 (J/cm). The solvent has a content not less than 0.1 ppm and not greater than 1000 ppm in the polyimide layer.

Fixing belt, fixing device, and image forming apparatus

A base for a fixing belt comprising at least: a nickel layer; and a copper layer, both laminated each other, wherein an orientation ratio I(200)/I(111) calculated based on a ratio between a peak strength of (200) crystal face and a peak strength of (111) crystal face by X-ray diffraction analysis of the copper layer is 0.1 or less. The base for the fixing belt further includes a protective layer, disposed on a surface of the copper layer opposite a surface on which the nickel layer is laminated, and the protective layer is formed of nickel.

Base for fixing belt, fixing belt, fixing device, and image forming apparatus

A fixing belt substrate for an image forming apparatus is prepared by an electroforming process. The fixing belt substrate contains nickel of prescribed weight percent, phosphorus of from about 0.4 weight percent or more to about 0.7 weight percent or less, sulfur of from about 0.003 weight percent or more to about 0.02 weight percent or less, and carbon of from about 0.012 weight percent or more to about 0.03 weight percent or less.

Substrate, fixing belt with substrate, fixing device with fixing belt, and image forming apparatus

A base for a fixing belt includes a nickel layer; and a copper layer, both laminated each other, wherein an orientation ratio calculated based on a ratio between a peak strength of crystal face and a peak strength of crystal face by X-ray diffraction analysis of the copper layer is 0.1 or less. The base for the fixing belt further includes a protective layer, disposed on a surface of the copper layer opposite a surface on which the nickel layer is laminated, and the protective layer is formed of nickel.

An optical information recording medium including a ROM region in which pits are previously formed at a track pitch (P); and a RAM region including a groove which is to be exposed to laser light to form at least one of a pit and a mark therein and to record information to be reproduced, wherein the pits in the ROM region are wobbled in a radius direction of the recording medium, a wobbling inter-pit groove is formed along the wobbled pits, wherein the width (W) of the inter-pit groove is narrower than that of the groove in the RAM region. The ratio (W/P) of the width (W) of the inter-pit groove to the track pitch (P) is preferably from 0.2 to 0.4.

Optical information recording medium and information recording method using the recording medium

An optical information recording medium having a ROM area in which pre-pits are arranged in a line in advance, wherein a groove having a depth smaller than a depth of the pre-pits is formed between the pre-pits, and the groove has a width at junction parts smaller than a width of a part of the groove other than the junction parts. Preferably the following relationships are satisfied: &#xbd; Wg&#x2266;Wpg&#x3c;Wg; and Wpg&#x3c;Wp, where Wp, Wpg and Wg represent a width of the pre-pit, the width of the groove at the junction parts, and the width of the other part of the groove other than the junction parts, respectively.

Optical information recording medium with ROM area having pre-pits

A mark representing information of a multivalued level is recorded in each of cells arranged in a recording medium. Upon reproducing the multivalued level from a reproduction signal of the recording medium, the multivalued level of a present cell is judged by referring to a judged multivalued level of a preceding cell preceding the present cell or an ensuing cell ensuing the present cell, or by referring to the judged multivalued levels of both the preceding cell and the ensuing cell.

Information reproducing method judging a multivalued level of a present cell by referring to judged multivalued levels of a preceding cell and an ensuing cell

An information recording medium includes a transparent substrate and a recording layer or a metal layer provided on the transparent substrate directly or via a ground layer. The information recording medium has a RAM area on which information is recorded, reproduced or erased, and a ROM area from which only reproduction is made, and an average thickness of the recording layer of said RAM area is larger than that of the recording layer or metal layer of the ROM area.

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Kanagawa, Japan

Yasuhide Fujiwara