Ricoh Company, Ltd.

Michihisa Takahashi

Yuki Nakamura

Katsuyuki Yamada

Yukio Ide

Eiji Noda

Kenichi Aihara

Kiyotaka Iiyama

Fumiya Ohmi

Shigeru Kusakata

Kyohji Hattori

Takeshi Matsui

Hideo Watanabe

Masanaka Nagamoto

Masanori Rimoto

Takayuki Hoshina

A method of initializing a phase-change optical information recording medium is provided, using an optical system incorporating a semiconductor laser device. The laser device is characterized by a specified spatial power distribution. In a spatial distribution of the laser power focused on the recording medium, in the direction perpendicular to guide tracks the laser device preferably has less average smaller in both end regions of the spatial distribution, which have each 10% of the width at half maximum of the distribution, than the average in the center region of the full width at half maximum of the distribution.

Initialization of phase-change optical recording medium

A diazo-type thermosensitive recording material is disclosed, which comprises a support material and a thermosensitive coloring layer formed on the support material, which thermosensitive coloring layer comprises a diazonium compound, a coupler and a thermo-fusible or thermo-softening material, the coupler being a combination of a hydrazone-type coupler of the formula of R.sup.1 --NH--N.dbd.CH--R.sup.2 (wherein R.sup.1 and R.sup.2 are defined in detail in the specification) and a two-valence metal compound capable of chelating with the coupled product produced by the coupling of the diazonium compound and the hydrazone-type coupler.

Diazo-type thermosensitive recording material with hydrazone coupler and

Catalyst bed for use in decomposition of ammonia gas, which comprises a mixture of catalysts for use in decomposition of ammonia gas and granules of catalytically inert substances.

Catalyst bed for use in decomposition of ammonia gas

A developing chamber and inlet and outlet chambers leading to and from the developing chamber respectively are uniformly heated in such a manner that ammonia gas used as a developing agent and water vapor are prevented from being condensed and contaminating copy sheets.

Developing apparatus for diazo copying machine

Growing community of inventors

Tachikawa, Japan

Michihisa Takahashi