Eastman-kodak Company

Bruce Ha

James A Barnard

Thomas C Burgo

William James Mueller

Michael A Inchalik

Steven A Glaza

Cheryl M Bianchi

Donald A Fairman

Larry L Smearer

A laser beam recording system for exposing a photoresist master disc having a photoresist layer formed over a substrate for making a hybrid optical recording disc having a read only (ROM) portion and a writable portion, including a first optical modulator for modulating an intensity of a first laser beam having a wavelength selected to provide activating radiation to expose a pattern in the photoresist layer formed over the substrate of the master disc between a lower intensity for exposing a groove in the photoresist layer and a higher intensity for exposing the groove and a pattern of depressions in the groove in the photoresist layer; and a second optical modulator for frequency-modulating an intensity-modulated second laser beam with a wobble-frequency to cause the exposed groove to be a continuously frequency-modulated groove. The recording system also includes a laser beam modulation control system for controlling the operation of the first and second optical modulators to form a continuously frequency-modulated exposed groove with exposed depressions in the ROM portion of the exposed groove. The first and the second laser beams can be provided by one laser as a single laser beam, by one laser as two split laser beams, and by a first and a second laser.

System for making a photoresist master for a hybrid optical recording disc

A copy-protected optical disc, including a preformed identification number (ID) in the ATIP signal and the subcode which is impressed upon the optical disc and a number of other optical discs during optical disc manufacture, a unique identification number for the optical disc which was written on the optical disc after it is manufactured; and an encrypted program written onto the optical disc wherein the encryption of such program is based upon the preformed ID and the unique ID and includes two or more selectable security levels.

Copy protection using multiple security levels on a programmable CD-ROM

A hybrid optical recording disc having copy protection for use in a computer, including a read-only area having preformed information including at least one program and disc identifier data; a recordable area; and the disc identifier data being adapted to authenticate a transferred program in the computer to permit the program to be operated by the computer.

Hybrid optical recording disc with copy protection

A hybrid disc including a preformed portion; and the preformed portion including a partial preformed session and a writeable portion including a wobbled groove which is adapted to be written to by a writer to complete the partial preformed session.

System to reduce writing overhead to a hybrid optical disc

A hybrid optical recording disc having a substrate and a recording layer disposed over the substrate, the substrate having a read-only (ROM) area in which a groove is modulated by depressions in the substrate and a recordable area in which the groove from the read-only area extends into the substrate in the recordable area. The groove in the read-only area forming wobbling tracks having a depth greater than 170 nm and wherein the depth d of the depression in the groove in the read-only area is in a range greater than 170 nm and less than 350 nm.

Hybrid optical disc construction

A method of forming a watermark image in a hybrid optical master disc is disclosed. The method includes the steps of projecting a watermark image on a photoresist layer of the master disc; exposing a spiral wobbled groove and depressions in the groove in a ROM area thereof; developing the exposed areas of the photoresist layer to provide physical depressions, a physical spiral wobbled groove and a physical watermark image; forming a stamper having the physical features of the developed photoresist layer; replicating the physical features in a plastic substrate with the stamper; and coating the plastic substrate with a recording medium structure to provide a hybrid optical disc having a watermark image in the plastic substrate under the recording medium structure.

Method of forming a watermark image in a hybrid optical master disc

A hybrid optical recording disc having a substrate and a recording layer disposed over the substrate, the substrate having a read-only (ROM) area in which a groove is modulated by depressions in the substrate and a recordable area in which the groove from the read-only area extends into the substrate in the recordable area, the groove in the read-only area forming wobbling tracks having a depth greater than 170 nm.

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Webster, NY, United States of America

Bruce Ha