Optical recording device and method

Abstract

Before new information is recorded on a comparatively deep recording layer in a multilayer optical recording disc, a predetermined target value of a reproduced signal parameter is read from the disc itself or from a separate storage unit, the recorded / unrecorded states of the shallower recording layers are determined, and the target value is corrected on the basis of these states. The correction is based on a predetermined difference in the value of the reproduced signal parameter caused by a difference in the recorded / unrecorded states of the shallower recording layers. The corrected target value is used in calibration of the recording power by means of a test write. This correction of the target value permits reliable recording on a multilayer optical disc without delaying the start of the recording process.

Description

technical field [0001] The present invention relates to an optical recording device and method for recording information on an optical disc having a plurality of recording layers, and in particular to optimal control of recording power (OPC: Optimum power control, optimal power control). Background technique [0002] In order to record information on an optical disc, it is necessary to perform OPC (Optimum Control of Recording Power) based on trial writing before recording information, and to optimally adjust the recording power. In a multilayer optical disc having a plurality of recording layers, when recording is performed on a layer located on the rear side as viewed from the side (laser incident surface) on which the recording light enters, the optimum recording power depends on the layer located on the near side. It differs depending on whether it is recorded or not. Therefore, in the information recording area, it is necessary to set the recording power so that the pe...

AI Technical Summary

Problems solved by technology

[0007] In the conventional optical recording devices of the above-mentioned Patent Documents 1 and 2, recording is performed in an area where OPC is performed so as to form a plurality of small areas in which the combination of recorded state / unrecorded state of other layers is different from each other. OPC is performed for each small area, so OPC takes a long time, and there is a problem that the time until recording starts is long

In addition, since many areas are required for one OPC, the number of times that the recording power can be optimized is limited, and there is a problem that the number of times information can be written is limited

[0008] In addition, in the conventional optical recording device of Patent Document 3, the recorded state and the unrecorded state are judged based on the amount of reflected light in the space portion, but there are cases where the reflectance fluctuates due to the non-uniform formation state of the recording film of the optical disc. In this case, misjudgment may occur, and it may not be possible to record at the optimum recording power.

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