Abstract: An optical disc drive (1), capable of handling optical discs (2) with at least two storage layers (61, 62), comprises an axially displaceable objective lens (34) and a focus actuator (52) for controlling the axial position of the objective lens; a control circuit (90) for generating actuator control signals (SQF) for the focus actuator; and a threshold source (98) for providing a threshold level (VT) lower than a supply voltage (Vs) for the focus actuator. The control circuit (90) monitors a focus disturbance signal and delays a layer jump if the absolute value of the focus disturbance signal is too high. Particularly, the control circuit compares the absolute value of the disturbance signals with said threshold level and, if this absolute value is higher than said threshold level, inhibits (83) the layer jump until the absolute value of the disturbance signals becomes lower than said threshold level.

Abstract: An optical disc discriminating method and an optical disc discriminating apparatus which can discriminate a type of optical disc with a simple configuration, causes a drive means to vary an incident angle of a laser light beam with respect to an optical disc while irradiating the optical disc with the laser light beam from a light beam generating section, causes a photodetector to detect a diffraction light of the laser light beam from a recording track of the optical disc, detects a value corresponding to the incident angle when the diffraction light is detected, and discriminates the type of the optical disc on the basis of the detected value.

Abstract: An optical disk device includes: an objective lens for focusing an optical beam on a recording layer of an optical disk; a converging lens for converging the reflected optical beam reflected on the recording layer; first and second light receiving units disposed at positions spaced ahead and behind at equal distances from the focal point of the reflected optical beam converged by the converging lens; and a focused recording layer discriminating unit for deciding, on the basis of the output signal of the first light receiving unit and the output signal of the second light receiving unit, the positional relation in a two-layer optical disk between a focused recording layer, on which the optical beam is focused, and a defocused recording layer, on which the optical beam is not focused, thereby to discriminate the focused recording layer on the basis of the decision result.

Abstract: The optical disk drive of the present invention can read data from multiple types of optical disks and includes: a motor for spinning a given optical disk; at least one light source for radiating light beams with multiple different wavelengths; at least one lens for converging each light beam onto the disk; a spherical aberration correcting section that can change the spherical aberration states of the beam; and a control section for controlling the operations of the motor, light source, lens and spherical aberration correcting section. The control section includes a disk type recognizing section that irradiates the disk with a light beam using the light source and the lens, thereby recognizing the type of the disk.

Abstract: A recording method and a malfunction detection method of an optical disc device are provided. The level of a signal driving a laser diode is detected during a recording operation. The detected level is compared with a reference limit, and the recording operation is controlled according to the comparison result. If the detected level exceeds the reference limit, a recording speed or power is adjusted downwardly, otherwise it is adjusted upwardly. If the detected level exceeds the reference limit, a malfunction in a front photodetector inside the optical disc device is reported to an external host. Appropriate control of the recording operation according to the disc reflection light incident on the front photodetector prevents degradation of recording quality. The reporting of the abnormality/malfunction in the optical disc device or the front photodetector makes it possible for the user to take a quick action against the abnormality or malfunction.

Abstract: An additionally recordable information recording medium has a complicated management structure for managing an unrecorded area. Therefore, there are problems that it takes a long time for a disk to startup and it is difficult to build a recording/reproducing system. The additionally recordable information recording medium according to the present invention includes a simple data structure for managing a location information for a recorded area located at the rearmost location in a user data area. An additionally recordable apparatus according to the present invention also includes means for updating the location information of the recorded area so that the recorded area located at the rearmost location in the user data area is always managed.

Abstract: A disk device is arranged to select an appropriate rotation control method according to a kind of an optical disk, a recording format or a recording method so that a recording operation for a certain amount of information may be completed as fast as possible, even if a waiting time takes place until the rotation is set. The disk device includes a unit for selecting the rotation control method for recording a certain amount of information more efficiently and rapidly in light of time according to a kind of an optical disk, a recording format or a recording method. The selected rotation control method is executed to control the rotation of the optical disk when recording information on the disk.

Abstract: An optical disk differentiating method applied to an optical disk drive, in which a first level value, a second level value and an optical disk differentiating value generating program are stored and an optical disk is put.

Abstract: A method for discriminating different types of optical discs includes the steps of focusing a beam spot generated by a laser source on an optical disc, and rotating the optical disc; generating a radio frequency signal and a corresponding first signal of the radio frequency signal; comparing a peak-to-peak value of the corresponding first signal with a predetermined value; determining the optical disc as a high density optical disc when the peak-to-peak value of the first signal is smaller than the predetermined value; and, determining the optical disc as a low density optical disc when the peak-to-peak value of the first signal is greater than the predetermined value.

Abstract: Disclosed herein are a high-density recording medium and a method and apparatus for controlling data playback thereof. Playback control information, such as channel bit length information, is recorded in a burst cutting area (BCA) of a high-density optical disc in a wobble type. When the high-density optical disc is reproduced, the playback control information is detected in a push-pull signal detection mode and the optimum data playback operation corresponding to the recording capacity of the optical disc is performed on the basis of the detected playback control information. Alternatively, bit error rates (BERs) are calculated while a plurality of predetermined bit detection modes are sequentially performed, one of the bit detection modes corresponding to the smallest one of the calculated BERs is selected and the data playback operation is performed in the selected bit detection mode.

Abstract: A BCA (Burst Cutting Area) code including a unique disk code indicating the type of a disk is written in a BCA code area of the disk. If the disk is mounted into the optical disk player, the optical disk player reads data written in the BCA code area, extracts the disk code contained in the read data, and confirms the type of the disk corresponding to the extracted disk code by retrieving a disk code table in which disk codes corresponding to the types of disks are mapped.

Abstract: To discriminate a disk in a short time, a calculating part 16 measures an amplitude of one of a focus error signal and a tracking error signal, which are output from a differential signal generating part 15, several times, and outputs the measured amplitudes to a controller 20. The controller 20 compares the input amplitudes with threshold values stored in a memory 21, respectively, and determines whether or not an amplification gain of one of the focus error signal and the tracking error signal is changed. If it is determined that the amplification gain of one of the focus error signal and the tracking error signal is changed, the controller 20 changes the amplification gain of one of the focus error signal and the tracking error signal to an amplification gain represented by one of the threshold values and discriminates the kind of an optical disk based on the changed amplification gain.

Abstract: In an optical disk recording method of recording data onto a recordable optical disk which includes a data zone where data is recorded and a management data zone where management data indicating the recorded part of the data zone is recorded, an extended management data zone in which the management data is to be recorded is set in the data zone in response to an extension instruction.

Abstract: Reflected light caused by reflection of a laser beam at a first layer of an optical disc is converted into a main signal. Reflected light caused by reflection of the laser beam at a second layer of the optical disc is converted into a sub signal. An address of a currently-accessed position in the first layer is detected from the main signal. A reference address in the first layer corresponds to a boundary between a signal recorded area and a signal unrecorded area in the second layer. A specified address in the first layer corresponds to a position radially separated from the position at the reference address by an allowable range. A misalignment between tracks on the first and second layers is concluded to be within the allowable range in cases where the sub signal substantially takes a reference level when the detected address reaches the specified address.

Abstract: A method of determining the transition shift timing in a measured optical signal from an optical recording medium as well as applications of the method in connection with optimizing a write strategy and analyzing the write quality for an optical recording medium are disclosed. The method comprising the step of: providing values of a measured optical signal, providing modulation bits corresponding to the measured optical signal, calculating a model signal by means of an optical channel model, and determining an output timing of the leading and trailing edges from a mathematical model. The method being a recursive method which is continued until a predetermined criterion is fulfilled. The final output is the average transition shifts of the channel bits of the measured CA signal as they are on the optical recording medium.

Abstract: A method and an apparatus for determining types of digital versatile discs (DVDs) are provided. The method includes setting related parameters, acquiring a wobble signal from a DVD, setting a frequency dividing factor, and dividing the frequency of the wobble signal by the frequency dividing factor. Then, the time required for the digital versatile disc to spin one round, which is driven by a spindle motor of a disc player, is set as a unit time to calculate the frequency of the frequency-divided wobble signal. Finally, the type of the digital versatile disc is determined according to the frequency of the wobble signal.

Abstract: A read out means reads out, from a multisession type optical disk which has been loaded, identification information which indicates its type, and a recommended write strategy pulse width. A calculation means, when a decision means has decided that the multisession type optical disk is of an unknown type, calculates a compensated pulse width based upon the value of the difference between the average value of the intrinsic write strategy pulse widths which are stored by a strategy storage means in correspondence with the identification information, and the recommended write strategy pulse width which has been read out by the read out means. And a recording means performs recording of data with laser light which has been modulated to the compensated pulse width as calculated by the calculation means.

Abstract: A high-density multi-layer optical disc and a method for managing layer formatting thereof. A high-density multi-layer optical disc such as a Blu-ray disc rewritable (BD-RE) dual layer includes management information, additionally recorded in a lead-in area, needed for identifying formatting status of a plurality of recording layers. After the management information is referred to, at least one unformatted recording layer is automatically formatted. Optionally, the unformatted recording layer is formatted on the basis of a formatting method selected by a user. The multiple recording layers formed on the high-density multi-layer optical disc can be conveniently and effectively formatted.

Abstract: A high-density multi-layer optical disc and a method for managing layer formatting thereof. A high-density multi-layer optical disc such as a Blu-ray disc rewritable (BD-RE) dual layer includes management information, additionally recorded in a lead-in area, needed for identifying formatting status of a plurality of recording layers. After the management information is referred to, at least one unformatted recording layer is automatically formatted. Optionally, the unformatted recording layer is formatted on the basis of a formatting method selected by a user. The multiple recording layers formed on the high-density multi-layer optical disc can be conveniently and effectively formatted.

Abstract: In a recording medium, the physical characteristic information of the recording medium, and more specifically, the configuration (shape and size) and the moment of inertia of the disc, is recorded. This enables a recording apparatus or a reading apparatus to easily and correctly determine the physical characteristics of the disc, and thus to perform suitable settings for the recording or reading operation.

Abstract: A method of discriminating a type of recording medium and a discriminating apparatus in which the type of recording medium is discriminated based on a temperature change of the recording medium when the recording medium is heated. A type of recording medium is discriminated based on a phase difference between a pulse signal input to a heating device and a pulse signal output by a detecting device detecting a temperature of a recording medium.

Abstract: The object of the present invention is to enable the identification of double-layer disc type (recordable double-layer disc, rewritable double-layer disc and ROM-type double-layer disc) to be easily and accurately performed. The method for identifying double-layer disc contains obtaining a reflectance of each light by irradiating light of different wavelengths under focused state to each layer of a double-layer disc loaded in an optical apparatus, and identifying if the double-layer disc is a recordable double-layer disc, a rewritable double-layer disc or a ROM-type double-layer disc corresponding to the combination of reflectance of each obtained light. It is preferable that the wavelength of one light is a wavelength for DVD-based disc and the wavelength of the other light is a wavelength for CD-based disc.

Abstract: A device for detecting wobbles on an optical disc is provided, where the device is utilized for generating a wobble signal according to a plurality of detection signals. The device includes an analog signal processing circuit, a pair of analog-to-digital converters (ADCs), and a digital signal processing circuit. The analog signal processing circuit is arranged to perform analog signal processing on the detection signals to generate a plurality of output signals. In addition, the pair of ADCs are arranged to digitalize the output signals to generate a plurality of digital values. Additionally, the digital signal processing circuit is arranged to perform digital signal processing on the digital values and generate an arithmetic output, where the arithmetic output is utilized for generating the wobble signal or utilized as the wobble signal. An associated method for detecting wobbles on an optical disc is further provided.

Abstract: A method for detecting a size of an optical disk loaded in an optical disk drive is disclosed. The optical disk drive has an optical pickup head, and the initial position of the optical pickup head is located on the outer side of a track. The steps of the method are described as follows. First, the optical disk is loaded. Then, the optical pickup head is moved from the initial position to a first position, and a laser beam is irradiated simultaneously. The laser beam reflected by the optical disk is received by the optical pickup head. According to the condition of the reflected laser beam received by the optical pickup head, the size of the disk can be determined.

Abstract: The invention relates to video player devices intended to play a video content DSC including audio tracks forming a disc audio languages list DAL and/or subtitles forming a disc subtitle languages list DSL, in a given number of languages. According to the invention, said device comprises a user interface UIA enabling the user to define a list of interesting languages UPL and a memory MEM to store the list of interesting languages UPL. Said device can then generate a dynamic menu ATL, STL intended to be displayed by filtering of the languages list DAL, DSL of the audio tracks present on the disc in accordance with the list of interesting languages UPL. Said dynamic menu ATL, STL is such that languages of the list of interesting languages UPL have priority in the dynamic menu ATL, STL. The invention enables the user to make an easier choice of a language for video content including audio tracks and/or subtitles in many different languages.

Abstract: A discriminating method of ascertaining the format of the loaded optical disc for an optical disc device is disclosed. When the optical disc device operates under a close-loop control, related central error signal is amplified and measured, while the peak-to-peak value of the amplified central error signal is then compared with a threshold. The loaded optical disc will be discriminated as a R-type medium if the peak-to-peak value of the amplified central error signal is larger than the threshold. On the contrary, the loaded optical disc is identified as a ROM-type medium if the peak-to-peak value of the amplified central error signal is smaller than the threshold.

Abstract: Separate sets of optical medium identification information are embedded in separate aligned layers of the optical medium to allow an optical drive to initiate use of the optical medium with information from both layers. For instance, a first set of identification information is embedded in the data layer of the optical medium and a second set of identification information is embedded on the protective surface layer of the optical medium. The first and second sets of information align so that a mixed signal is provided when the optical medium is initially inserted in the optical drive with the optical drive reading the separate sets of information while the read head is at a single location.

Abstract: A verify operation is the one that is carried out to further improve reliability of recorded data. Because recording and reproduction are made repeatedly, however, the same time is consumed for reproduction even if recording is made at a double-speed, for example, and recording is substantially equal to recording at a normal recording speed. The verify operation is effective for further improving reliability but reduces the substantial recording speed to a half. To improve recording performance by automatically turning ON and OFF the verify operation in accordance with disks, medium information called “media ID” unique to a disk is acquired in a read-in area of the optical disk. The existence/absence of the verify operation is determined on the basis of a matrix table of an existence/absence of the verify operation corresponding on the 1:1 basis to each media ID provided in advance to an optical disk drive.

Abstract: A method, medium, and device changing a play mode if an error occurs in a process of discriminating the type of optical discs. The method includes the operation of discriminating a type of an optical disc loaded in an optical player, and if the optical disc is discriminated as one of a plurality of optical discs that belong to a first type, setting the play mode of the optical player to a play mode corresponding to the type of the discriminated optical disc, reading and playing data recorded in the loaded optical disc, and if the optical player is unable to reproduce the data recorded in the optical disc, then changing the play mode of the optical player to a play mode for reproducing one of a plurality of optical discs that belong to a second type.

Abstract: An audio/video data recording/reproducing device is provided that allows all video and audio signals, which can be displayed by a display of the audio/video data recording/reproducing device proper, to be output to an exterior through a digital interface. Such audio/video signals are in the forms of, for example, files as recorded including a moving picture file, a still picture file, and a file resulting from synthesization of a moving picture file with a still picture file. When the digital interface of the recording/reproducing device is connected to a digital TV, a synthesized signal from a synthesizing part 117, after being encoded into an MPEG-TS in an encoder 103, is output from a 1394 interface part 121. When the digital interface is connected to another editor or recording device, a recording signal from a reproducing part 116 is output as it is from the 1394 interface part 121.

Abstract: This invention improves the accuracy of wobble signal detection for disc discrimination and reduces discrimination errors due to noise. In an optical disc apparatus, a wobble signal generator creates a wobble signal from an electrical signal which has been obtained from conversion by a pickup. A bandpass filter (BPF) is set to change its central frequency to a wobble frequency f0 and to fn different from the wobble frequency, and the filter extracts the respective frequency components from the wobble signal. An amplitude-measuring section measures amplitude levels A0 and An of the extracted multiple signals. A disc discriminator compares the multiple amplitude levels and if the amplitude A0 is greater than the amplitude An by at least a threshold level Ath, judges that a wobble is present.

Abstract: An optical disk unit of this invention includes a defocus detecting system for detecting a defocus of an objective lens, a thickness unevenness detecting system for detecting a thickness unevenness of a transparent resin layer provided nearest the objective lens of a recording medium, and a thickness unevenness correcting mechanism for changing the focusing characteristic of light impinging upon the objective lens based on a change in the thickness of the transparent resin layer detected by the thickness detecting system.

Abstract: A method for determining the type of digital versatile discs (DVDs) is provided, for distinguishing among a read only memory (ROM) DVD, a recordable DVD and a re-writable DVD. The method includes reading a tracking error signal from a DVD. If the amplitude of the tracking error signal is greater than a first predetermined value, the DVD is a recordable DVD; otherwise, a recorded area (RECD) signal is read from the DVD. If the RECD signal is zero, the DVD is a blank re-writable DVD; otherwise, a total RF level signal is read from the DVD. If the total RF level signal is greater than a second predetermined value, the DVD is a DVD ROM; otherwise, the DVD is a re-writable DVD with data.

Abstract: An interface device for an optical recording and/or reproducing apparatus for recording and playback of an optical disc, wherein the configuration of an interface circuit between a pickup that reads and writes information from/on the optical disc and a radio frequency (RF) integrated circuit (IC) for signal processing is simplified. To this end, the interface device includes a pickup, an integrated circuit, and a multiplexer. The pickup drives a plurality of laser diodes generating laser signals to record and/or reproduce information on a plurality of discs, respectively, and receives the laser signals reflected from the discs and output photodiode (PD) signals corresponding respectively to the received laser signals. The integrated circuit controls outputs of the laser diodes, and processes the PD signals from the pickup.

Abstract: A disk apparatus that includes: a first determining unit that determines whether the maximum value of an amplitude of an RF signal is a first reference level or more and the minimum value of the detected amplitude of the RF signal is a second reference level or less; a counting unit that counts the number of detected times of CAPA areas according to the determining results of the first determining unit; a second determining unit that determines whether the optical disk has been rotated a given amount or not; a third determining unit, when the optical disk has been rotated a given amount, determines whether the number of detected times of CAPA areas is at least equal to or larger than a given number of times or not; and a fourth determining unit that distinguishes the kind of the optical disk according to the determining results of the third determining unit.

Abstract: An optical disc apparatus is adapted to load an optical disc inserted in a slot into a main body and to read and reproduce data stored on the optical disc. The optical disc apparatus temporarily prevents a loading means from loading an optical disc into the main body if a guide flag stored in a storage means is off when the optical disc is inserted in the slot. At the same time, the apparatus instructs a guide image outputting means to output a guide image that indicates a proper orientation in which the optical disc is to be inserted into the slot.

Abstract: An image processing apparatus and data erasing method make it possible to unrecoverably erase encrypted data recorded in an auxiliary storage device at high speed while reducing the load put on the CPU. Upon reception of a data erase request from a data utilizing process, the data requested to be erased is registered in a predetermined storage unit. The data registered in the storage is unrecoverably erased by overwriting, and an area in the auxiliary storage device in which the erased data was stored is released after the overwriting erasure process.

Abstract: An optical disk that has a BCA, from which data can be reproduced even if the BCA has defects. The data format of the BCA comprises a plurality of sub-data units and coupling codes, each coupling two adjacent sub-data units. The sub-data units contain the same data. To reproduce the data, the sub-data units are checked for errors. The data recorded in any sub-data unit that has no errors is reproduced and output to a next stage circuit connected to the optical disk drive.

Abstract: In a DVD-R on which information is to be recorded by an information recording apparatus, prior to the recording of the information therein, there are recorded in advance at least identification information for identifying the information recording apparatus for recording the information onto the DVD-R, and recording parameter information containing optimization information for optimizing a recording state in the record processing executed by the information recording apparatus specified by the identification information. Furthermore, the information recording apparatus reads the recording parameter information at the execution of record processing to use it for the record processing.

Abstract: An offset amount measuring method is provided with: a recording process for measurement (i) of recording information for measurement, into a recording track in the L0 layer, by a predetermined section, from a measurement reference position, and of (ii) recording the information for measurement, into a recording track in the L1 layer, by the predetermined section, from or toward a measurement correspondence position, which is associated with the measurement reference position by the pre-format address; a first detecting process of detecting a border of a first recorded area in which the information for measurement is recorded and a first unrecorded area in the first recording track, on the basis of a difference in reflectance between the first recorded area and the first unrecorded area; a second detecting process of detecting a second border position in the recording track in the L1 layer, on the basis of a difference in reflectance; and a determining process of determining the offset amount, on the basis of

Abstract: In a recording medium, the physical characteristic information of the recording medium, and more specifically, the configuration (shape and size) and the moment of inertia of the disc, is recorded. This enables a recording apparatus or a reading apparatus to easily and correctly determine the physical characteristics of the disc, and thus to perform suitable settings for the recording or reading operation.

Abstract: A disc transport apparatus for detecting a disc-shaped recording medium with specified diameter, transporting the disc-shaped recording medium to a chucking position, but not transporting a disc-shaped recording medium with different diameter, when detected, to the chucking position includes a recording medium mount section capable of mounting a first disc having a first diameter and a second disc having a second diameter that is smaller than the first diameter, an optical detection unit that uses a light receiving section for receiving reflected light from a detection target in response to light emitted from a light emitting section and that is provided at a position opposite a disc having the first diameter when the disc is mounted on the recording medium mount section and at a position not opposite a disc having the second diameter when the disc is mounted on the recording medium mount section, and a control section for determining whether a disc is mounted based on a detection result of the optical detect

Abstract: According to a preferred embodiment of the present invention, in order to provide a tilt control method and optical disc apparatus capable of exerting control to eliminate tilt and capable of carrying out an appropriate gap servo operation, a light gathering element positioned facing a disc recordable with a signal, and capable of gathering light irradiated from a light source as near-field light at a position where a distance to the disc constitutes a first distance is made to come into contact with the disc (step 2), and tilt is controlled with the light gathering element in contact with the disc (steps 3 to 7). As a result, tilting with respect to the disc is adjusted with the SIL in contact with the disc, tilting can be eliminated in a reliable manner, and a gap servo operation can be carried out in an appropriate manner.

Abstract: A method of writing data to an optical disc comprising determining a disc category value to be written to an optical disc, and writing, by an optical disc drive, the disc category value to the optical disc, the disc category value written to the optical disc different than a standardized disc category value associated with a disc category type of the optical disc is provided. A computer-readable medium having stored thereon an instruction set to be executed, the instruction set, when executed by a processor, causes the processor to perform a computer method of determining an optical disc category value, and writing, by an optical disc drive, the disc category value to an optical disc, the disc category value written to the optical disc different than a standardized disc category value associated with a disc category type of the optical disc is provided.

Abstract: An apparatus is described for recording a visually detectable pattern on a record carrier (40), comprising a first (10) and a second module (20). The first module (10) is arranged for: receiving information that specifies the visually detectable pattern, issuing a request to the second module to provide indications, indicative for capabilities of recording the visually detectable pattern at the record carrier, issuing instructions for applying the visually detectable pattern at the record carrier using the received information, depending on the indicated capabilities of recording, and wherein the second module (20) is arranged for providing the requested indications, and generating the visually detectable pattern at the record carrier (40) using the issued instructions.

Abstract: An optical disc drive according to the present invention can read data from any of multiple types of optical discs, of which the information storage layers are located at mutually different depths under their surface. When this drive is loaded with an optical disc, the servo controller of the drive changes a first type of drive signal to adjust a focus position by changing distances from the lens to the disc and/or a second type of drive signal to adjust tilt of the lens by changing the angles defined by the lens with respect to the disc a number of times, thereby changing settings to be determined by a combination of the focus position and the tilt. A signal quality rater measures multiple index values to rate the quality of a reflected light signal as the settings are changed. Then, the optical disc drive recognizes the type of the given optical disc based on those index values and reads data from the optical disc recognized.

Abstract: The present invention provides a method of recording identification information in an optical disc, by which specified disc identification information can be uniformly applicable to efficiently cope with the recording/reproducing of the optical disc. The present invention includes recording a disc identification information in a management area of the optical disc wherein the disc identification information identifies a disc type identified according to a disc surface protecting scheme including presence or non-presence of a protective coating, disc surface test completion, or cartridge use necessity.

Abstract: A medium judgment method determines authorization of a rewritable storage medium of interest having a read-only area and a rewritable area for use in an optical disk drive. In the medium judgment method, a specific information of the medium is acquired from an information reproduction area of the read-only area of the medium. It is determined whether contents of the medium are authorized based on the acquired specific information. Running of a starting process of the optical disk drive with the medium is permitted when the authorization of the medium is determined as being correct. Running of the starting process of the optical disk drive with the medium is inhibited when the authorization of the medium is determined as being incorrect.

Abstract: There are provided a mounting unit configured to selectively mount first and second optical disks in which characteristics of recording films are different from one another, and a discriminating unit configured to discriminate which of the first and second optical disks is mounted on the mounting unit based on a level of a reproduction signal which is obtained by reproducing innermost peripheral portion of the first or second optical disk mounted on the mounting unit.

Abstract: An object of the present invention is to provide a marking forming apparatus, a method of forming a laser marking on an optical disk, a reproduction apparatus, an optical disk, and a method of manufacturing an optical disk, capable of providing a greatly improved copy prevention capability as compared to prior known construction. To achieve this object, in the optical disk of the invention, for example, a marking is formed by a laser on a reflective film of a disk holding data written thereon and at least position information of the marking or information concerning the position information is written on the disk in an encrypted form or with a digital signature appended thereto.