Abstract: Aspects of the disclosure provide a sync mark detector. The sync mark detector includes a first unit configured to decay over time a value indicating a length of a bit format, a second unit configured to compare the decayed value with a detected length of the bit format to determine a new length, and a third unit configured to detect a sync mark based on the detected length and the new length.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for performing data decoding.

Abstract: Disclosed is an information recording medium (1) having a plurality of pits (301) which are formed periodically, wherein information is recorded by irradiating a laser beam onto a pit string constituted by the plurality of pits (301) and changing the shape of the pits (301), the pit string is periodically wobbled, a length of a period (fp) of the pits (301) is a diffraction limit of the laser beam or less, and the period of the pit string is n times (n is a positive integer) of the period of the pits.

Abstract: In a system of detecting an interference light with a light not irradiated onto an optical disc to increase the S/N ratio, it is difficult to stably acquire a reproduced signal with a simple configuration. Since the recording density is not improved, an improvement in transfer rate is difficult. In an optical information recording/reproducing apparatus where two optical beams face each other and are focused at the same place of a recording medium to record a standing wave developed by interference of the two optical beams, a phase difference of the two optical beams is modulated in a multiple stage and recorded. During reproduction, an interference light of a reproduced light from the recording medium and another reproduction reference light is detected as a reproduced signal, and a phase servo control stabilizing the phase of interference during reproduction by using a low frequency component of the reproduced signal is conducted.

Abstract: A record carrier has a servo track indicating an information track intended for recording information blocks, which servo track has a variation of a physical parameter, referred to as wobble. The wobble is modulated for encoding record carrier information, such as addresses. The servo track is subdivided in non-modulated and parts modulated parts in which the frequency and/or phase of the variation deviates from the wobble frequency. The slope of the wobble is substantially continuous at transitions between the modulated and non-modulated parts by using wobbles starting at the maxima or minima of the wobble.

Abstract: An optical tape decoding system includes a decoder that may apply a matched pattern signal representing an address index to a track address signal including a multi-cycle wobble block representing the address index such that a signal is output having a peak corresponding to the multi-cycle wobble block. The decoder may also identify the address index based on an amplitude of the peak.

Abstract: According to one embodiment, an information storage medium in which layer 0 and layer 1 are arranged from a read surface, a system lead-in area, data lead-in area, data area, and middle area are arranged from an inner circumference of the layer 0, and a system lead-out area, data lead-out area, data area, and middle area are arranged from an inner circumference of the layer 1. A guard track zone is arranged on a side of the data area in the data lead-out area, and a reference code zone, R physical format information zone, recording management zone, and drive test zone are arranged in the data lead-in area of the layer 0 and padding of the guard track zone of the data lead-out area is performed after padding of the drive test zone of data lead-in area and recording of the recording management zone.

Abstract: According to an embodiment, a storage medium includes a transparent resin substrate having a concentric or spiral groove and a recording film formed on the groove on the transparent resin substrate, a recording mark being formed by irradiation of a laser beam, wherein a reproduction durability count in a case where reproduction is continuously carried out by a laser beam is 1,000,000 or more.

Abstract: In one embodiment the present invention includes a circuit comprising a switch and a switch driver. The switch is configured to provide synchronous rectification switching of a back-EMF voltage. The synchronous rectification switching produces a source voltage. The switch driver is configured to receive the back-EMF voltage and the source voltage. The switch driver provides a control signal to a control terminal of the switch. The control signal has a frequency. The frequency is used to control an amount of the synchronous rectification switching. Accordingly, the frequency reduces a dissipated power associated with the synchronous rectification switching.

Abstract: Circuits, architectures, systems, methods, software, and algorithms for detecting a modulation transition (e.g., a change from a written portion containing RF-modulated data to an unwritten portion containing only a wobble signal modulation) on an optical storage medium. The method generally includes steps of focusing a first spot of light onto an optical storage medium, wherein the first spot is substantially centered on a first track of the optical storage medium, focusing a satellite spot of light onto an optical storage medium, wherein the satellite spot at least partially overlaps a track adjacent to the first track, generating a satellite signal from light reflected from the optical storage medium from the satellite spot, and detecting the modulation transition by detecting a change in a level of the satellite signal.

Abstract: The present techniques provide methods and systems for alignment of a read head with data tracks on an optical data disk. In embodiments, a multi-pixel detector that is segmented into multiple areas, or detector segments, may be used to detect a pattern in the light reflected from an optical data disk. The detector system may then combine the quantized values from each of the detector segments mathematically to determine the alignment of the read head with a target data track. If the read head drifts to one side or the other, detectors to the side of a center detector may start to pick up energy from the adjacent tracks. If this energy is continuously summed for the detectors on each side, the read head may be centered by balancing the sums from the detectors on each side.

Abstract: An apparatus and method to record data on a holographic storage medium, the apparatus including: a light processing unit to record the data on the holographic storage medium using a reference beam and a signal beam, the light processing unit including a light modulator to modulate the signal beam; and a control unit to control the light processing unit to record the data on the holographic storage medium, wherein the light modulator modulates the signal beam so that an image formed on a surface of the light modulator is shorter in a radial direction that is a scanning direction of the reference beam than in a tangential direction that is perpendicular to the radial direction.

Abstract: The present invention provides a recording and reproducing apparatus that can perform high-precision tracking servo control by removing noise from detected servo signals. The recording and reproducing apparatus performs tracking servo control while reading servo signals 10 that are formed on a surface 9 of a recording medium 2 so as to produce optical contrast, the apparatus including a modulated irradiator 20 for irradiating the servo signals 10 with a light beam, the intensity of the light beam being modulated by a modulating wave that is frequency-modulated; a photoelectric converter 30 for converting reflected light from the servo signals 10 into electric signals; and a synchronous demodulator 15 for subjecting the electrical signal to synchronous demodulation using the modulating wave as a reference wave.

Abstract: A decoding apparatus includes a burst cutting area (BCA) signal interval measuring device which measures a signal interval of a BCA area and which outputs BCA signal interval information, a T converter which obtains T information from the BCA signal interval information, a sequencer which detects a space area based on a first threshold value and which outputs an output enable signal based on the T information and a detecting result, wherein the output enable signal shows that a signal is obtained from a data area of the BCA area, and the space area is a non-signal area of the BCA area, and a channel data converter which converts the T information into channel data based on the output enable signal from the sequencer.

Abstract: A demodulation circuit accurately demodulates a wobble signal of an optical disk without being affected by a phase shift induced by crosstalk. An A-D converter subjects wobble signal reproduced from an optical disk to A-D conversion and feeds a result of conversion to a zero-crossing detection circuit. The zero-crossing detection circuit detects zero-crossing points of the wobble signal. A sinusoidal wave generation circuit generates a sinusoidal wave by means of sequentially connecting sinusoidal wave elements whose periods are each equal to a time interval between zero-crossing points. A multiplier multiplies an original wobble signal by a sinusoidal wave signal. A slicer detects an HMW-modulated portion of the wobble signal, and another slicer detects an MSK-modulated portion of the wobble signal.

Abstract: An optical disc device including a high frequency band processing circuit for removing low frequency components of signals outputted from plural photodetectors of a pickup, and generating various kinds of signals required for recording/playback of an optical disc by digital processing after performing AD conversion by a high-speed low-bit AD converter; and a low frequency band processing circuit for removing high frequency components of the signals outputted from the respective photodetectors of the pickup, and generating various kinds of signals required for recording/playback of an optical disc by digital processing after performing AD conversion by a low-speed high-bit time-division AD converter.

Abstract: A visible pattern is obtained by modulating the digital sum value. Because the digital sum value modulation allows the choice of several different channel bits groups between DC control points, the selection of a group of channel bits resulting in a change of reflection. This creation of a visible pattern is highly suitable for Blueray as the parity preserving property of the channel code guarantees disparity inversion by the DC-control bit, which keeps the DSV excursions between hard limits. As a result only small DSV deliberate variations are required to produce a visual watermark, which will not deteriorate the bit-detection margin of the optical disc.

Abstract: An optical data recovery system including an optical receiver configured to receive light reflected from an optical medium and produce modulated data, a processing unit configured to transform the modulated data into a series of transform coefficients respectively identifying frequencies of the modulated data at respective times, and the processing unit is configured to identify from the series of transform coefficients defect coefficients associated with positions in the modulated data where the modulated data is corrupted.

Abstract: There is provided an optical reproduction device that reproduces a hologram that is recorded on an optical recording medium by interference between a signal light and a reference light coaxial to the signal light. The device has: a coherent light source; a light distribution unit distributing light from the light source, to a signal light optical path and a reference light optical path; a spatial light modulator that includes a signal light region and a reference light region, a spatial light modulator, a first irradiation optical system spatially separating light distributed to the reference light optical path and light distributed to the signal light optical path, making optical axes of both lights coincide, and irradiating the both lights onto the spatial light modulator; and a second irradiation optical system irradiating reference light onto the optical recording medium as reading light, and reproducing the hologram.

Abstract: There is provided an optical reproducing device including: a reproducing component that includes a light source, a spatial light modulator, and a light guiding component, with the reproducing component irradiating, with reference light that has been generated by the spatial light modulator as reading light, a Fourier transform hologram; a splitting component disposed on a signal light exiting side of the reproducing component and that splits, into two light waves, the signal light; a first image acquiring component that detects the one split light wave to acquire a first reproduced image; a second image acquiring component that detects light where a direct current component has been removed from the other split light wave to acquire a second reproduced image; and a decoding component that uses the first reproduced image and the second reproduced image to decode data that the signal light has.

Abstract: According to one embodiment, an information storage medium in which layer 0 and layer 1 are arranged from a read surface, a system lead-in area, data lead-in area, data area, and middle area are arranged from an inner circumference of the layer 0, and a system lead-out area, data lead-out area, data area, and middle area are arranged from an inner circumference of the layer 1. A guard track zone is arranged on a side of the data area in the data lead-out area, and a reference code zone, R physical format information zone, recording management zone, and drive test zone are arranged in the data lead-in area of the layer 0 and padding of the guard track zone of the data lead-out area is performed after padding of the drive test zone of data lead-in area and recording of the recording management zone.

Abstract: A holographic optical information recording/reproducing device is provided with a laser light source 1 and a polarizing beam splitter 8 for splitting a light from the laser light source 1. At the time of recording information, one of light beams split by the polarizing beam splitter 8 is modulated by a spatial light modulating element 2 to form a beam array, which becomes a signal light 25, whereas the other split light beam becomes a reference light 22. Interference fringes generated by the signal light 25 and the reference light 22 are recorded as holograms in a holographic disc 5. At the time of reproducing the information, only the reference light 22 is irradiated to the holographic disc 5 and its diffracted light is detected.

Abstract: A high frequency modulator is described. It comprises: a first converter for receiving a constant current signal and transmitting a first converted signal; an adder coupled the first converter and operative for transmitting a summed signal in response to receiving the first converted signal and selectively receiving a triangular signal; a first oscillator coupled to the adder for receiving the summed signal, the first oscillator operative for transmitting a time varying current signal; a second converter coupled to the first oscillator for receiving the time varying current signal and operative for transmitting a second converted signal; and an output device selectively coupled to the second converter and operative for transmitting an output signal in response to receiving either the second converted signal or an offset signal.

Abstract: A hologram recording/reconstructing apparatus includes a spatial modulator in which a reference beam region and a reconstruction beam region are formed, and a controller configured to control a range of the reference beam region and a range of the reconstruction beam region. According to a temperature of a hologram recording medium during recording, the controller sets the range of the reference beam region to a first predetermined range and thereby sets a range of an incident angle of a reference beam on the hologram recording medium to a first predetermined angle range. According to a temperature of the hologram recording medium during reconstruction of recorded data, the controller sets the range of the reconstruction beam region to a second predetermined range and thereby sets a range of an incident angle of a reconstruction beam on the hologram recording medium to a second predetermined angle range.

Abstract: An address information modulation method includes using a first characteristic of a first modulation method and a second characteristic of a second modulation method to modulate address information and/or additional information. Accordingly, a data amount of information, to access a disc, in a predetermined space of the disc is increased, and the modulated information is formed in a form of a wobble signal in a track. Here, the first characteristic of the first modulation method can be physical location information of an MSK-modulated signal, and the second characteristic of the second modulation method can be sign information of a second harmonic wave obtained by an HMW modulation, which synthesizes a cosine function of a basic frequency of a wobble signal with a sine function having a frequency that is a multiple of the basic frequency of the wobble signal.

Abstract: The present invention relates to a scanner for optical storage media with an improved signal-to-noise ratio. In the case of an optical scanner according to the invention having a light source for generating a light beam for reading out data stored on an optical storage medium, the light source being modulated by a radio-frequency modulator, and having an analog-to-digital converter, which converts an analog data signal generated by a photodetector into a digital data signal), the radio-frequency modulator and the analog-to-digital converter are synchronized.

Abstract: A data processing apparatus for outputting a plurality of picture data forming reproduced data to a reproduction apparatus for reproduction, the data processing apparatus having a processing circuit for judging if the reproduction rate of the picture data by the reproduction apparatus is slower than a transfer rate for transferring the picture data to the reproduction apparatus and outputting all of the picture data forming the reproduced data to the reproduction apparatus when judging as a result of the judgment that the reproduction rate is slower than the transfer rate.

Abstract: Provided are a recording medium, a recording medium playing device and method, which has an EFM demodulation unit for adaptively realigning an EFM demodulation point. The recording medium demodulates first data into second data in response to a channel clock signal recovered from the first data, compares a demodulation point indicating demodulation of the first data into the second data with an alignment point set in response to the first data, and jumps the demodulation point forward or backward by a difference between the demodulation point and the alignment point.

Abstract: To detect an MSK modulation mark from an MSK-modulated wobble signal without fail. A wobble signal of an optical disk is supplied to an address decoding circuit. The address decoding circuit performs exclusive-OR operation of a binarized wobble signal and a reference clock signal generated from the wobble signal by an PLL circuit, to thus compute a proportion of the exclusive-OR result assuming a value of one every half period of a reference clock signal. When there are continuously present a predetermined number of sections or more where a proportion becomes a predetermined threshold proportion or more, the sections are detected as an MSK modulation mark. A system controller changes the threshold proportion in accordance with crosstalk from an adjacent track.

Abstract: A light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.

Abstract: A system for modulating digital binary data to be recorded on a recording medium comprises the generation of channel bits of the digital binary data to be recorded according to a standard for the recording medium with the exception that a maximum run length larger than that defined in the standard is obtained and/or the merging decision is influenced on basis of a random noise in a predetermined pattern or in at least one predetermined position on said recording medium and/or by recording at least one part comprising at least one predetermined repetitive bit pattern which normally, i.e. according to the standard for the recording medium, encodes into channel bits having a spectral distribution that shows at least one range of frequencies with a characteristic amplitude distribution.

Abstract: To provide an optical disc device 1, and similar, equipped with a new mechanism to reduce laser light noise due to optical feedback. In an optical disc device 1 in which a laser diode is driven by a high frequency modulation method, optical feedback is returned to the laser diode at a timing at which the phase of the injected carrier density is within one of the following ranges: (1) equal to or greater than the peak phase of the injected carrier density of the laser diode, and equal to or less than the peak phase of the injected carrier density of the laser diode plus 3?/8 (radians); or (2) equal to or greater than the peak phase of the injected carrier density of the laser diode plus 9?/8 (radians), and equal to or less than the peak phase of the injected carrier density of the laser diode plus 2? (radians).

Abstract: Compressed audio data for 5.1 channels stored in the DVD-ROM 11A is read by the AC-3 decoder 12 of a pseudo multi-channel stereo play-back apparatus and, after expansion, stored temporarily in a buffer 13, channel by channel. Among stored audio data stored in the buffer 13, audio data for left and right channels and for a front center channel are then subjected to the phase transformation. Audio data for left and right front channels are mixed with the phase transformed audio data by first and second mixing circuits 21 and 22 and mixed audio data are converted into analog audio signals by first and second D/A converters. The apparatus is capable of pseudo reproduction of the multi-channel audio signals stored in a recording medium such as a DVD-ROM by two channel play-back with an excellent sound effect which is not obtainable by usual two-channel play-back systems.

Abstract: The present invention is applicable to a recording apparatus of a CD or DVD, a recording method thereof and a recording medium, and an object of the present invention is to clearly record a second information such as characters and figures between two recording levels in an optical disk. The second information is recorded in a predetermined area in a radius direction and a angular direction on the optical information recording medium, and further, the second information is recorded according to a change of a pit width based on a change of power of the laser beam, a change of a pit length based on an on/off control of the laser beam, or a change of depression or bulge of the pit based on a change in the vicinity of the on/off control of the laser beam. Whereby it is possible to record the second information such as a watermark pattern or a visible image, which is capable of being confirmed by seeing a disk.

Abstract: A reproducing apparatus includes a signal reading unit for reading a signal from a recording medium, an equalizing unit for performing partial response equalization on the read signal and outputting an equalized signal, a maximum likelihood decoding unit for performing maximum likelihood decoding on the equalized signal to decode binary data and outputting a binary data string, a determining unit for determining whether or not a shortest code in the binary data string obtained by the maximum likelihood decoding is correct, on the basis of information on an amplitude of the equalized signal corresponding to the shortest code, a code correcting unit for correcting the shortest code in the binary data string, in accordance with a result of the determination of the determination unit, and a data demodulating unit for demodulating the binary data string obtained through the code correcting unit to obtain reproduction data from the recording medium.

Abstract: A record carrier has a servo track indicating an information track intended for recording information blocks, which servo track has a variation of a physical parameter, referred to as wobble. The wobble is modulated for encoding record carrier information, such as addresses. The servo track is subdivided in non-modulated and parts modulated parts in which the frequency and/or phase of the variation deviates from the wobble frequency. The slope of the wobble is substantially continuous at transitions between the modulated and non-modulated parts by using wobbles starting at the maxima or minima of the wobble.

Abstract: The invention relates to a method for generating a primary binary signal having a predetermined spectral shape in a predetermined frequency range, in particular having a notch in the power spectrum in a predetermined frequency range. In order to avoid crosstalk between a primary binary signal and a secondary binary signal it is proposed according to the invention that data-words are modulated into channel-words forming the channel bitstream of the primary binary signal and that the modulation of the data-words is chosen such that the predetermined spectral shape of the channel bitstream of the primary binary signal is achieved by using an evaluation criterion based on a spectral weight function the shape of which is tailored to the spectral extent of the channel bitstream of a secondary binary signal.

Abstract: A pre-treating circuit for accessing the disc and a method thereof, which are especially used for treating the signal waveform that violates the encoding rule of the disc information, are provided. The present invention can modulate the signal waveform that violates the encoding rule, so that the waveform is not changed during at least 3 continuous periods of the clock signal. The present invention also replaces any wrong 16-bit data which violate the encoding rule, with approximated 16-bit data before they are decoded, or receives approximated 8-bit data which correspond to the incorrect 16-bit data, by directly referring to a table. Therefore, the subsequent decoding module can acquire more data for continuous processing, so as to improve the data reading reliability and to prevent the “picky disc” or “disc error reading” problem from happening.

Abstract: A demodulator includes a wobble signal processor configured to convert a waveform of a wobble signal, and to generate a clock and a reference value based on a converted wobble signal. A sampling circuit is configured to sample the converted wobble signal by using the clock, and to generate a sampled signal. A viterbi decoder is configured to decode an auxiliary recording signal superposed on an optical disk by using the reference value and the sampled signal.

Abstract: Without waiting for the rotational speed of an optical disk reaches a rotational speed (Vb) for a reproduction process, a cutoff frequency (Fca) of an RF signal and a boost amount (Bt) for an equalizer circuit are detected, and, with using the rotational speed (Va) of the optical disk at this detection, the cutoff frequency (Fc) by which jitter of the RF signal is optimized when the optical disk is rotated at the rotational speed (Vb) for the reproduction process is calculated by the equation of Fc=Fca+k(Vb?Va), and then set. Therefore, the time between the timing when the user conducts an input operation for starting reproduction, and that when reproduction is actually started can be shortened, and the usability can be improved.

Abstract: Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit (22, 23) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc.

Abstract: A method and apparatus for recording or reproducing data in which high performance encoding and a high efficiency decoding are realized to lower the decoding error rate. A magnetic recording and/or reproducing apparatus 50 includes, in a recording system, a modulation encoder 52 for modulation encoding input data in a predetermined fashion and an interleaver 53 for interleaving data supplied from the modulation encoder 52 to re-array the data sequence.

Abstract: An optical recording medium on which a header signal having multi-modulated header information is recorded, an apparatus and method of recording the header signal, and an apparatus and method of reproducing header information from the header signal of the optical recording medium which includes a wobbled track on which user data is recorded, and a header area in which a header signal having multi-modulated header information is recorded. Accordingly, the optical recording medium increases the recording density of header information, thereby providing a wider user data area.

Abstract: An optical disc cutting apparatus capable of suppressing an unnecessary deflection component and unnecessary light intensity variation component and manufacturing a optical disc suitable for a high definition, high precision and high density optical disc.

Abstract: Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit (22, 23) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc.

Abstract: Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit (22, 23) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc.

Abstract: Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit (22, 23) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc.

Abstract: The invention relates to a reproduction or recording apparatus for different optical recording media, which differ for example with regard to their storage density, are scanned by different means and have a photodetector arrangement that is jointly used for the different recording media and scanning means, which arrangement provides a photodetector signal which is independent of the absolute light power level of the laser diodes. For generating the photodetector signal which is independent of the absolute light power level of the laser diodes, a switch for changing over the sensitivity of the photodetector is provided, which switch is controlled by the modulator for generating a uniform light power with a laser diode. A connecting line to the basic apparatus and corresponding terminals for controlling the switch are advantageously obviated as a result.

Abstract: Described herewith is an optical disk manufacturing apparatus for reading recorded digital data from an optical disk, comprising an encryption unit (22, 23) for encrypting entered digital data according to a plurality of key information; an optical disk substrate manufacturing unit 2 for manufacturing an optical disk substrate 4 on which the encrypted digital data and key information are recorded in the form of physical form changes; a reflection film forming unit 41 for forming a reflection film on the optical disk substrate 4; and a key information recording unit 7 for recording key information on the optical disk substrate on which the reflection film is formed. The reflection factor of the optical disk is changed locally, thereby giving a jitter to the position information of each pit edge, and desired data is recorded additionally according to this jitter. Pits, etc.

Abstract: A pre-treating circuit for accessing the disc and a method thereof, which are especially used for treating the signal waveform that violates the encoding rule of the disc information, are provided. The present invention can modulate the signal waveform that violates the encoding rule, so that the waveform is not changed during at least 3 continuous periods of the clock signal. The present invention also replaces any wrong 16-bit data which violate the encoding rule, with approximated 16-bit data before they are decoded, or receives approximated 8-bit data which correspond to the incorrect 16-bit data, by directly referring to a table. Therefore, the subsequent decoding module can acquire more data for continuous processing, so as to improve the data reading reliability and to prevent the “picky disc” or “disc error reading” problem from happening.