Eastman-kodak Company

Frederick F Geyer

Eric M Leonard

Dennis G Howe

George M Myers

Jasper S Chandler

An improved method of optically writing and/or reading high density information involves: (1) predeterminedly positioning a flat, uniformly thick, flexible, optical disc with respect to an axis of rotation; (2) rotating the disc on such axis at a high speed and in a predeterminedly spaced relation to a predeterminedly shaped, smooth, featureless reference surface and (3) coupling a central region between the disc and reference surface to an ambient gas source. Related apparatus and disc configurations, including embodiments having flexible disc covers, also are disclosed.

Optical disc unit and method and apparatus for writing and/or reading

An optical write/read unit includes a support, an overlying record layer that is constructed for writing or reading with a predetermined light wavelength(s) and is absorptive to light of other wavelengths and a protective cover means that is selectively transparent to light of at least one of said predetermined wavelength(s). In one embodiment the disc unit is adapted for writing and reading with the same light wavelength and the cover means blocks other light wavelengths. In another embodiment the disc unit is adapted to reading with light of wavelength substantially different than the writing wavelength and the cover means selectively transmits the operative (write and read) wavelengths and selectively blocks a large proportion of other light wavelengths. In another embodiment the cover means is selectively transmissive to the reading wavelength and is displaceable to permit writing light onto the record layer.

Optical write/read unit with selective-transparency cover

An optical disk assembly includes a flexible disk-shaped support carrying a record layer. The support has an information storage region. An annular retaining ring engages the annular peripheral region of the support. The support, and preferably a cover sheet, are captured between the outer annular reference ring member and an inner annular reference ring member which has been conically deformed to spring toward the outer ring member.

Optical disk assembly

Spot-focus of a write or read beam upon a flexible optical disc, which is rotated with its neutral plane highly stabilized in space, is maintained precisely by moving the write or read beam source (e.g. a laser diode) in response to focus error signals.

Optical disc write/read methods and apparatus with improved focus and

An optical disc assembly includes a flexible disc-shaped support. An annular retaining ring engages the support around its periphery. The support carries a record layer with an information storage region of the record layer located between the retaining ring and a central hub. In use on cooperating optical disc write/read apparatus having disc assembly receiving structure, the central hub positions an annular area of the support, which area is radially inward of the storage region, against a locating surface of the receiving structure with a predetermined abutting force, whereby firm contact is assured between the support and the location surface radially inwardly of the storage region of the record layer. The disc assembly includes a flexible, transparent cover sheet which is coextensive with the support. Annular spacing means are provided between the support and the cover sheet both radially inwardly and outwardly of the information storage region to provide an axial space between the record layer and the cover sheet.

Optical disc assemblies for optical disc write/read apparatus

An optical disc assembly includes a flexible disc-shaped support. An annular retaining ring engages the support around its periphery. The support carries a record layer with an information storage region of the record layer located between the retaining ring and a central hub. In use on cooperating optical disc write/read apparatus having disc assembly receiving structure, the cental hub positions an annular area of the support, which area is radially inward of the storage region, against a locating surface of the receiving structure with a predetermined abutting force, whereby firm contact is assured between the support and the location surface radially inwardly of the storage region of the record layer. The disc assembly includes a flexible, transparent cover sheet which is coextensive with the support. Annular spacing means are provided between the support and the cover sheet both radially inwardly and outwardly of the information storage region to provide an axial space between the record layer and the cover sheet.

Optical disc write/read apparatus

An optical disc-unit including (i) a flexible, disc-shaped support bearing a record layer, (ii) a flexible disc-shaped cover sheet which is transparent to write/read light and (iii) annular retaining means which engage the support and sheet, in spaced relation, substantially continuously around peripheral regions. In preferred embodiments the retaining means symmetrically tension the sheet and support into substantially flat dispositions. Cooperative optical disc write/read apparatus and optical disc-unit fabrication methods are also disclosed.

Optical disc unit, fabrication method and cooperating write and/or read

An improved method of optically writing and/or reading high density involves: (1) predeterminedly positioning a flat, uniformly thick, flexible, optical disc with respect to an axis of rotation; (2) rotating the disc on such axis at a high speed and in a predeterminedly spaced relation to a predeterminedly shaped, smooth, featureless reference surface and (3) coupling a central region between the disc and reference surface to an ambient gas source. Related apparatus and disc configurations, including embodiments having flexible disc covers, also are disclosed.

Optical disc method, media and apparatus for writing and/or reading

Certain sources of optical radiation, such as diode lasers, emit an anamorphic beam of radiation that is linearly polarized along the major axis. The present invention provides optical apparatus that corrects for such beam anamorphicity through the use of vector diffraction effects.

Growing community of inventors

Rochester, NY, United States of America

Frederick F Geyer