Minnesota Mining and Manufacturing Company

Imation Corporation

Richard F Willson

William B Robbins

Kent N Maffitt

Vaughn W Halling

Joseph H Sexton

Gregory D Roberts

Thomas A Rinehart

Frank E Aspen

Robert P Freese

An optical data storage disk including a substrate, a nanocrystalline noise reduction layer formed over the substrate, a reflector formed directly on the noise reduction layer and a cover layer formed over the reflector layer. An optical source detects data from the disk through the cover layer. In some embodiments, the reflector layer forms part of a multilayer recording stack and the cover layer is formed over the multilayer recording stack. In some embodiments, the noise reduction layer includes one or more components selected from the group consisting of Ti, Ti alloys, Ti oxides, Cr, Cr alloys and Cr oxides. Additionally, a method of forming an optical data storage disk that includes a nanocrystalline noise reduction layer.

Noise reduction layer for optical data storage media

A carrier ( ) is used in the thin film coating of disks ( ). The disks ( ) are held in a disk tray ( ). The disks ( ) have a center ( ) through which the thin film coating can go through. The carrier ( ) includes a base plate ( ) for receiving the disk tray ( ). A plurality of discrete shields ( ) are positioned in alignment with the center openings of the disk ( ). The shields ( ) are releasably connected to the base plate ( ). Preferably, the shields ( ) are releasably connected by a magnetic force.

Method and apparatus for thin film center shielding

A method of exchanging a thin film coated tray ( ) for a clean tray ( ) is provided. The method replaces the tray ( ) at an intermediate position on the handler ( ) and not at an intermediate disk loading position of the rotating disk loading mechanism.

Method for a tray exchange during continuous production of disks

An air-incident, optical data storage medium has a substrate, a reflector layer, a magneto-optic recording layer, and a protective layer. The reflector later has at least one of an electrical conductivity greater than about 5.0&times;10,(&OHgr;-cm),, an RMS surface roughness less than about 1.0 nm as measured by atomic force microscopy, and an index of refraction of less than about 0.5 at a read wavelength.

Magneto-optical data storage disc with highly conductive, smooth reflector layer

A method for producing a magneto-optic layer includes depositing amorphous magnetizable film layer on a substrate using a triode sputtering process. The magneto-optic layer includes an alloy of terbium, cobalt, iron, chromium and an oxygen content approximately between 2-6 atom percent midway through the thickness of the layer.

Process for producing magneto-optic recording medium

Magneto-optic recording medium

The novel optical recording medium, as in the prior art, has a transparent substrate bearing two recording layers, each addressable from only one side of the medium, but unlike prior 2-sided media, the two recording layers are on the same face of the substrate. When the novel medium is addressed from one side of the substrate, a thin-film barrier, such as an opaque metal, between the two recording layers prevents the more distant recording layer from responding to that energy. Preferably a tough, transparent cover layer is sealed to the substrate to protect the two recording layers.

Two-sided optical recording medium

Optical recording medium having a laser-recordable light-absorbing layer which is a carbide of iron or chromium has surprisingly high sensitivity. High carrier-to-noise ratios are attained using a laser-diode recording system at power levels below 10 mW.

Optical recording medium of high sensitivity

An optical recording medium containing a light-absorbing film of refractory material less than 60 nm thick and selected from carbides of Al, Hf, Nb, Ta, Ti, V, W, and Zr and alloys herebetween, whereupon localized heating of the light-absorbing film enables information storage in the form of localized features in the heated areas which can subsequently be optically detected and can be used as a master information record for replication purposes.

Optical recording medium

An optical recording medium containing a light-absorbing film of a refractary material selected from the group, consisting of boron, borides of carbon, silicon, hafnium, niobium, tantalum, titanium, tugsten, and zirconium, nitrides of boron, hafnium, tantalum and titanium, oxides of hafnium, cerium, magnesium and thorium, and silicides of niobium, tantalum, titanium, and tungsten less than 60 nm thick and which is sufficiently plastic to allow deformation upon localized heating by exposure to a focused laser beam, whereupon the localized heating of the light absorbing film enables information storage in the form of localized protuberances in the heated areas which can be used as a master for replication purposes.

Protuberant optical recording medium

An optical recording medium containing a light-absorbing film of amorphous carbon less than 60 nm thick and which is sufficiently plastic to allow plastic information upon localized heating is provided for exposure to a focused laser beam, whereupon localized heating of the light-absorbing film enables information storage in the form of localized protuberances in the heated areas which can subsequently be optically detected and can be used as a master information record for replication purposes.

A method is disclosed for producing a micro structure on the surface of an article. The method comprises the steps of depositing a discontinuous coating of a material exhibiting a low rate of sputter etching on a substrate exhibiting a higher rate of sputter etching and differentially sputter etching the composite surface to produce a topography of pyramid-like micropedestals random in height and separation. The articles produced by this method are characterized by both the microstructured surface and by the detectable presence of the material exhibiting the lower rate of sputter etching. The microstructured surface results in the articles having uniform antireflecting properties over a large range of angles of incident light and over an extremely broad range of wavelengths, in which the antireflecting characteristic is obtained without an attendant increase in diffuse scattering. Also, the microstructured surface results in the articles being characterized by a high degree of adherence, such that the treated surface may be considered to be 'primed', thereby enabling the application of highly adherent coatings or layers thereon.

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Hudson, WI, United States of America

Richard F Willson