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Optical recording medium, reproducing system, method of reproducing optical disk, method of fabricating optical disk original record, and method of stopping illegal program operation

a technology of optical recording medium and reproducing system, which is applied in the field of optical recording medium, reproducing system, and reproducing optical disk, can solve the problems of difficult disk reproduction, and achieve the effect of preventing illegal duplication and difficult disk reproduction

Inactive Publication Date: 2008-05-20
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0017]A digital signal reproduced from an area containing a recorded signal, the center of an eye pattern of which is deviated from the center of the amplitude, by a reproducing system and demodulated into a digital signal is a normal signal, and if the demodulated signal is recorded on a recordable optical disk medium, when the recorded signal is reproduced, there results in the center of the eye pattern being substantially coincident with the center of the amplitude. Accordingly, if the reproducing system changes the threshold value and makes a reproduction in demodulating the RF signal into the digital signal, the signal is not reproduced as a normal signal so as to stop the reproducing operation. This makes the reproduction of the disk difficult and prevents the illegal duplication.

Problems solved by technology

This makes the reproduction of the disk difficult and prevents the illegal duplication.

Method used

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  • Optical recording medium, reproducing system, method of reproducing optical disk, method of fabricating optical disk original record, and method of stopping illegal program operation
  • Optical recording medium, reproducing system, method of reproducing optical disk, method of fabricating optical disk original record, and method of stopping illegal program operation
  • Optical recording medium, reproducing system, method of reproducing optical disk, method of fabricating optical disk original record, and method of stopping illegal program operation

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first embodiment

[0018]FIG. 1 is a block diagram showing an arrangement of an optical disk reproducing system according to the present invention;

[0019]FIGS. 2a-2i are illustrations of one example of common eye patterns with no offset in an optical disk;

[0020]FIGS. 3a-3i are illustrations of one example of eye patterns with a given offset in an optical disk;

[0021]FIG. 4 illustrates the variation of asymmetry due to the recording power and recording equalizing quantity in the first embodiment;

[0022]FIG. 5 is a block diagram showing one arrangement of a recording system for an optical disk original record in the first embodiment;

[0023]FIG. 6 is a block diagram showing an arrangement of a conventional recording system for an optical disk original record;

[0024]FIG. 7 is a block diagram showing an arrangement of a conventional optical disk reproducing system;

[0025]FIGS. 8A to 8D are illustrations for explanation of a recorded signal on an optical disk being an optical recording medium according to the fir...

second embodiment

[0038]FIG. 20 is a block diagram showing an arrangement of an optical disk reproducing system according to the present invention; and

[0039]FIGS. 21A and 21B show the first and second halves of a flow chart of a duplicated disk operation preventing program in the second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0040]First Embodiment

[0041]A description will be made hereinbelow in terms of an optical recording medium and an optical disk reproducing system according to a first embodiment of the present invention. According to this invention, a special copy protection signal different from the ordinal signal is mixed into a recording signal in manufacturing an original record for optical ROM disk such as CDs being optical recording media, thereby fabricating a special original record which can prevent the duplication. This special copy protection signal is expressed as a CP signal. As shown in FIG. 8A, in an optical disk which is an optical recording medium according to the firs...

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Abstract

The present invention provides an optical disk 9 with a duplication preventing function, reproducing system 47 for the optical disk 9, optical disk reproducing method, method of fabricating an optical disk original record, and illegal program operation stopping method. An area in which a CP signal 24 is recorded is made after a signal having a constant pattern in the optical disk, the CP signal 24 being produced such that the center of an eye pattern is shifted from the center of the amplitude. In the reproducing system, CP signal arrangement information 25 or a CP preceding signal 26 is detected, before an offset voltage is applied to a threshold value to be used in demodulating an RF signal into a digital signal so that the threshold value varies, thus normally reproducing the signal in which center of the eye patter is shifted from the center of the amplitude. The reproducing system has a function whereby the reproduction is stopped when a predetermined offset signal is not reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION[0001]1. Industrial Application Field of the Invention[0002]The present invention relates to prevention of duplication of a recording medium, and more particularly to an optical disk with a duplication preventing function, a method of fabricating such an optical disk, a method of reproducing an optical disk, a reproducing system, a method of fabricating an optical disk original record, and a method stopping an illegal program operation.[0003]2. Description of the Prior Art[0004]Generally, fabrication of Optical disks succeeds manufacturing of the original record, master, mother and stamper, and optical disks are duplicated and mass-produced from the stamper in accordance with the injection molding technique. The stamper can sometimes be manufactured directly from the original record. Generally, a photoresist is applied onto a glass-made surface-grinded substrate and photosensitized with a laser beam intensity-modulated in accordance with an infor...

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): B32B3/02G06F1/00G06F21/80G11B7/00G11B7/0037G11B7/005G11B7/007G11B7/013G11B7/24088G11B7/26G11B7/28G11B11/105G11B13/04G11B19/02G11B19/04G11B19/12G11B20/00G11B20/10G11B20/12G11B23/28G11B27/034G11B27/10G11B27/11G11B27/24G11B27/30G11B27/32G11B27/34G11B27/36
CPCG06F21/80G11B7/00736G11B7/013G11B7/24088G11B7/26G11B11/10595G11B13/04G11B13/045G11B19/02G11B19/04G11B19/12G11B19/122G11B20/00086G11B20/00123G11B20/00557G11B20/00586G11B20/00594G11B20/00601G11B20/1217G11B23/282G11B27/034G11B27/105G11B27/107G11B27/11G11B27/24G11B27/3027G11B27/3063G11B27/329G11B7/0037Y10T428/21G11B7/005G11B7/00745G11B7/261G11B7/28G11B20/10009G11B23/284G11B27/34G11B27/36G11B2007/0013G11B2020/1259G11B2220/20G11B2220/211G11B2220/213G11B2220/237G11B2220/2525G11B2220/2529G11B2220/2545G11B2220/2587G11B2220/65G11B2220/655G11B2220/90Y10S428/913G11B7/007
Inventor UENO, FUMIAKIOSHIMA, MITSUAKI
Owner PANASONIC CORP
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