Eastman-Kodak Company

Thomas C Burgo

Bruce Ha

James A Barnard

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 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 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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Brockport, NY, United States of America

Thomas C Burgo