Dynamic information storage or retrieval – Binary pulse train information signal – Binary signal gain processing
Reexamination Certificate
1998-10-19
2001-04-17
Edun, Muhammad (Department: 2651)
Dynamic information storage or retrieval
Binary pulse train information signal
Binary signal gain processing
C369S047360, C369S053130
Reexamination Certificate
active
06219322
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical information recording apparatus, an optical information recording method, an optical information recording medium and optical information reproducing apparatus which may be applied to a recording apparatus and a recording method for use in making an optical disc such as a compact disc (CD), an optical disc such as a compact disc and an optical disc reproducing apparatus such as a compact disc player, for example.
2. Description of the Related Art
In a compact disc which is a kind of optical information recording media, in order to identify a disc, codes representing a maker, a factory, a disc No. or the like are stamped on the inside of the area in which ordinary user information such as an audio signal and TOC (Table of Contents) are recorded. Also, there is proposed a method of recording such an identification code on a signal recording area as a pattern that can be confirmed visually.
The identification codes representing a maker, a factory, a disc No. and the like that are recorded by these methods can be visually recognized and cannot be read out by a reproducing apparatus such as a compact disc player. There is then the problem that contents of these identification codes cannot be reflected on controlling an operation of the reproducing apparatus (e.g. the reproduction of an audio signal from a compact disc produced by an illegal copy cannot be stopped).
SUMMARY OF THE INVENTION
In view of the aforesaid aspect, it is an object of the present invention to provide an optical information recording apparatus and an optical information recording method in which identification codes that can be read out by a reproducing apparatus and which may not spoil ordinary user information may be recorded on an optical information recording medium together with ordinary information, an optical information recording medium in which such identification codes are recorded together with ordinary information and an optical information reproducing apparatus for reproducing the identification code from such optical information recording medium together with ordinary information.
According to a first aspect of the present invention, there is provided an optical information recording apparatus for recording digital information on an optical information recording medium by modulating recording light irradiated on the optical information recording medium. This optical information recording apparatus comprises a first modulation signal generating circuit for generating a first modulation signal by switching a signal level at an integral multiple period of a predetermined fundamental period in response to first digital information, a second modulating circuit for generating a double modulation signal by further modulating the first modulation signal in response to second digital information other than the first digital information, and a recording light modulating circuit for modulating the recording light in accordance with the double modulation signal.
According to a second aspect of the present invention, there is provided an optical information recording method of recording digital information on an optical information recording medium by modulating recording light irradiated on the optical information recording medium. This optical information recording method comprises the steps of generating a first modulation signal by switching a signal level at an integral multiple period of a predetermined fundamental period in response to first digital information, generating a double modulation signal by modulating a timing at which a level of the first modulation signal is changed in response to second digital information other than the first digital information, and modulating the recording light in accordance with the double modulation signal.
In accordance with a third aspect of the present invention, there is provided an optical information recording medium in which digital information is recorded by forming a track composed of a pit or a mark. This optical information recording medium is characterized in that first digital information is recorded by changing a length or interval of the pit or mark so as to obtain a reproduced signal which changes at an integral multiple period of a predetermined fundamental period and second digital information other than the first digital information is recorded by moving a front edge or a rear edge of the pit or mark from a position determined by the first digital information.
According to a fourth aspect of the present invention, there is provided an optical information reproducing apparatus for reproducing digital information from the optical information recording medium based on an output of an optical reading device responsive to a reflected light amount of an optical information recording medium. This optical information reproducing apparatus comprises a binary value generating circuit for generating an output of the optical reading means in the form of binary value, a clock generating circuit for generating a clock signal based on an output from the binary value generating circuit, a first decoding circuit for decoding first digital information based on an output from the binary value generating circuit, and a second decoding circuit for decoding second digital information other than the first digital information based on an output from the optical reading device, the clock signal and an output from the binary value generating circuit, wherein the second decoding circuit includes a change point position detecting circuit for detecting a time fluctuation of a change point of an output from the binary value generating circuit and an averaging circuit for averaging outputs of the change point position detecting circuit.
According to the optical information recording apparatus and the optical information recording method of the present invention, when ordinary user information is recorded on the optical information recording medium as first digital information, a double modulation signal is generated by further modulating the first modulation signal, which is generated by switching a signal level at an integral multiple period of a predetermined fundamental period in response to this ordinary information, in response to second digital information (e.g. identification code for identifying the optical information recording medium). Recording light is modulated in accordance with the double modulation signal, whereby the identification code is recorded within an ordinary information recording area together with the ordinary information. Accordingly, only by adding a simple hardware to a conventional recording apparatus and only by simply modifying a conventional recording method, the identification code may be recorded within the ordinary information recording area together with the ordinary information without modifying a disc manufacturing factory and the like at all.
According to the optical information recording medium of the present invention, while the ordinary information is recorded on the optical information recording medium by changing a length or an interval of a pit or a mark on the track so as to obtain a reproducing signal which changes at an integral multiple period of a predetermined fundamental period, the identification code is recorded on the optical information recording medium by moving a front edge or a rear edge of the pit or the mark from a position determined by the ordinary information. Therefore, even when a user intends to make an illegal copy by physically copying a pit shape or the like of this optical information recording medium (genuine optical information recording medium), it is difficult to accurately copy the position of the front edge or the rear edge of the pit or the mark. Also, when a user intends to make an illegal copy based on an audio signal reproduced from this genuine optical information recording medium, according to the conventional recording apparatus and the conventional recording method, it is not possible to move t
Edun Muhammad
Frommer William S.
Frommer & Lawrence & Haug LLP
Sony Corporation
LandOfFree
Optical information recording apparatus, optical information... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical information recording apparatus, optical information..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical information recording apparatus, optical information... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485738