Abstract: An information recording medium having at least a read only area and a recording and reproducing area is composed of at least: a substrate; a recording layer formed on the substrate so as to record and reproduce information; and a light transmission layer having transparency formed on the recording layer. The information recording medium is further characterized in that a wobbling groove corresponding to the read only area and another wobbling groove corresponding to the recording and reproducing area is formed on the substrate without overlapping with each other, the recording and light transmitting layers are continuously adhered over at least two areas of the read only area and the recording and reproducing area, reflectivity of the recording layer is more than 5%, and a push-pull signal output T3 reproduced from the read only area and another push-pull signal output T4 reproduced from the recording and reproducing area before recording satisfies relations of T3?0.1, T4?0.1 and 1.5?T3/T4?0.5.

Abstract: An optical disc is manufactured under a uniform condition by forming grooves and lands on the entire surface of the disc. The optical disc is configured to obtain a reliable reproduction signal, and the grooves and lands are formed on a lead-in area, a user data area and a lead-out area of the optical disc. Since the same manufacturing condition can be adopted in mastering discs, the yield can be enhanced and the manufacturing cost can be reduced.

Abstract: The present invention relates to a method and a circuit for recovering information contained in a wobble track of an optical storage medium. One aim of the invention is to describe a method within an appliance for reading from and/or writing to optical storage media, which can correct disturbing data signal components in the wobble signal even when the swept frequency and the lowest signal frequency are close to one another. According to the invention, this object is achieved in that the signals from two detector halves of a photodetector which is used for reading the data contained in a track on an optical storage medium are provided with weighting factors which are adjusted dynamically during operation of the appliance for reading from and/or writing to optical storage media. In order to adjust the weighting factors, the obtained swept-frequency signal is linked to a data signal.

Abstract: A method for optical drive decoding of address in pre-groove (ADIP) data is provided to decode an input wobble signal to an ADIP unit signal. The method includes generating a wobble carrier frequency signal having the same phase with the wobble signal, multiplying the wobble carrier frequency signal by the input wobble signal to generate a product signal, accumulating the value of the product signal in each clock to generate a quotient summation signal, determining the phase change of the input wobble signal according to the value of the quotient summation to generate a phase change signal, and generating the ADIP unit signal by comparing the phase change signal with a plurality of ADIP patterns.

Abstract: An optical disk comprises a track groove on which positional information indicating a physical location on the track groove is represented by a wobble shape of the track groove. The optical disk includes a plurality of positional information units that are arranged on the track groove. Each said positional information unit includes: a positional information section that represents the positional information by a combination of wobble patterns selected from multiple types of wobble patterns that have been defined so as to correspond to respective signal waveforms that rise and fall mutually differently; a sync mark section having a wobble pattern in a shape distinguishable from the wobble patterns of the positional information section; and a precision positioning mark section ahead of each said positional information section.

Abstract: Deflecting means, for deflecting an electron beam in a radial direction and the circumferential direction, and blanking means, for shielding irradiation of the electron beam at portions other than drawing portions, are provided. While the disk is rotated unidirectionally, the electron beam is repeatedly deflected in a figure 8 pattern, in which the electron beam is deflected toward the next deflection initiation point in the radial direction at track edge portions, such that the deflected directions toward the inner periphery of the disk and toward the outer periphery of the disk intersect each other. Parallel scanning is performed alternately toward the outer periphery and the inner periphery of the disk. Elements of a transfer pattern, having lengths which are integer multiples of a reference value, are drawn by performing scanning a number of times equal to the integer that the reference value is multiplied by.

Abstract: A recording medium includes a substrate having a microscopic pattern, which includes a shape of continuous substance of approximately parallel grooves formed with a convex shaped section and a concave shaped section alternating on a surface of the substrate. A recording layer is formed on the microscopic pattern and a light transmitting layer has a thickness of 0.05 mm to 0.12 mm formed on the recording layer. The microscopic pattern satisfies a relation of P??/NA, wherein P is a pitch of the convex shaped section, ? is a wavelength of a reproducing light beam and NA is a numerical aperture of an objective lens. The microscopic pattern also includes modulated address information formed on both side walls of the convex shaped section viewed from the light transmitting layer as a wobble, both the side walls being parallel to each other, and furthermore wherein the address information is modulated by the phase-shift keying modulation system.

Abstract: An information recording medium 1 at least comprises a substrate 13 having a microscopic pattern 20, which is constituted by a shape of continuous substance of approximately parallel grooves formed with a groove section G and a land section L alternately, a recording layer 12 formed on the microscopic pattern 20 and a light transmission layer 11 formed on the recording layer. The microscopic pattern 20 is formed so as to satisfy a relation of P<?/NA and a thickness of the light transmission layer 11 is within a range of 0.07 to 0.12 mm, wherein P is a pitch of the groove section G or the land section L, ? is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens. Further, there provided an information recording medium, which is improved in cross erase and recorded in high density, and a reproducing apparatus and a recording apparatus for the information recording medium.

Abstract: An optical disc is manufactured under a uniform condition by forming grooves and lands on the entire surface of the disc. The optical disc is configured to obtain a reliable reproduction signal, and the grooves and lands are formed on a lead-in area, a user data area and a lead-out area of the optical disc. Since the same manufacturing condition can be adopted in mastering discs, the yield can be enhanced and the manufacturing cost can be reduced.

Abstract: A wobble signal detecting circuit for optical disc system includes at least a sample-and-hold circuit for carrying out sample-holding steps on each of first and second photoelectric signals, and a high range frequency limiting circuit for removing frequency components equal to, or higher than, a predetermined cut-off frequency from the first and second photoelectric signals. By selectively enabling either the sample-and-hold circuit or high range frequency limiting circuit, depending on recording conditions during the period of recording information into an optical information recording medium, noise components which may unduly affect wobble signals can be removed efficiently, irrespective of recording conditions.

Abstract: A recording medium is provided, which maximizes the recording capacity and simplifies the configuration of an information recording/reproducing apparatus including a pickup. In the medium, different types of wobbling signals are preformatted in each of the adjacent land and groove signal tracks. A same-phase wobbling signal provided by wobbling each side of the respective land and groove signal tracks in the same phase, and a different-phase wobbling signal provided by wobbling each side of the respective land and groove signal tracks in a different phase are used as the different types of wobbling signals. The physical positions of all the land and groove signal tracks are indicated by the same-phase wobbling signal.

Abstract: A reproducing apparatus for reproducing information recorded on an optical recording medium including a disk-like substrate, a plurality of tracks extending in a circumferential direction on the substrate and associated with a plurality of grooves, with a plurality of zones provided on the disk-like substrate and extending between a first position and a second position in a radial direction of the substrate. Each zone includes at least two tracks with each track being divided into a plurality of recording units of circular arc shape extending in the circumferential direction. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

Abstract: A wobble demodulator for reproducing digital information from an optical recording medium in which a track is formed in accordance with a wobble signal that is MSK-modulated so as to contain the digital information by a carrier signal with a predetermined frequency and a sine wave signal with a frequency different from that of the carrier signal, includes: a wobble signal detector for detecting a wobble signal of the track from the optical recording medium; a wobble PLL for detecting the carrier signal based on the wobble signal detected by the wobble signal detector; a multiplier for multiplying the carrier signal detected by the wobble PLL by the wobble signal detected by the wobble signal detector and outputting a multiplied output; a MSK detector for detecting a MSK modulation mark having a phase or a frequency different from that of the carrier signal, based on an integrated value obtained by integrating the multiplied output from the multiplier on a predetermined section basis; and a MSK synchronization

Abstract: An apparatus and method for detecting a wobble signal read from an optical disc. The wobble signal detection apparatus comprises an analog/digital (A/D) converter for A/D-converting an analog wobble signal, read from the optical disc and then band pass filtered, a slope detector for detecting a slope of the A/D-converted wobble signal according to a variation thereof, and a wobble signal detector for detecting a peak point of the A/D-converted wobble signal using the detected wobble signal slope, and detecting/outputting a square-wave wobble signal with a high level or low level transition at the detected peak point. The slope detector calculates variations of data values of the A/D-converted wobble signal sampled within a predetermined period on the basis of predetermined different weights, accumulates the calculated values and detects the slope of the A/D-converted wobble signal on the basis of the accumulated value.

Abstract: A reproducing apparatus for reproducing information recorded on an optical recording medium including a disk-like substrate, a spiral or concentric-shaped groove structure along a track formed on the substrate, and the groove structure being wobbled in a radial direction of the medium. The track is divided into a plurality of recording units in the track direction by at least one radial boundary line formed by a dropout portion, wherein identification information is disposed in the track at a head of each recording unit at the dropout portion. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

Abstract: A physical identification data (PID) addressing method using a wobble signal, a wobble address encoding circuit, a method and circuit for detecting the wobble address and a recording medium therefor. Groove tracks are classified into odd groove tracks and even groove tracks. Address information indicating physical identification information is phase modulated using wobble signals having a predetermined phase difference between two adjacent groove tracks, and recorded in each groove track so that address information modulated using the wobble signals having the phase difference of 90° between adjacent two groove tracks can be a quadrature phase shift keying (QPSK) signal. Accordingly, a larger amount of data can be recorded on the recording medium, and since an interval in which a wobble signal disappears is not caused, recovery of a wobble clock signal can be advantageously performed.

Abstract: A recording method for an optical medium including a disk-like substrate, a spiral or concentric-shaped groove structure along tracks formed on the substrate, each of the tracks being divided into a plurality of units, each of the units including a dropout portion of the groove structure which is a non-groove portion along the track in a circumferential direction of the track, the groove structure being wobbled in a fixed cycle in a radial direction which continues in the circumferential direction along the track. When the wobble is formed in the circumferential direction of the track, the dropout portion is formed so that a phase of the wobble is continued with a phase of the wobble of the groove structure within another unit adjacent to the dropout portion. The method includes providing the optical medium, and recording information by irradiating an optical spot on the medium.

Abstract: An optical disc includes a read-only area having a first wobble, which is a data wobble formed in the read-only area for only reading, a readable/writable area having a second wobble, which is different from the data wobble, and a connection area between the read-only area and the readable/writable area having a third wobble having the same frequency as one of the first and second wobbles.

Abstract: A reproducing apparatus for reproducing information recorded on an optical recording medium having a disk-like substrate, a spiral or concentric-shaped groove structure along tracks formed on the substrate, and each of the tracks being divided into a plurality of recording units. Each of the recording units includes a dropout portion of the groove structure which is a non-groove portion along the track in a circumferential direction of the track, and the groove structure is wobbled in a fixed cycle in a radial direction, which continues in the circumferential direction along the track. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

Abstract: A recording method for an optical medium having a disk-like substrate with a spiral or concentric-shaped groove structure along a track formed on the substrate. The groove structure is wobbled in a radial direction of the medium and the track is divided into a plurality of units in the track direction by at least one radial boundary line formed by a dropout portion. Identification information is disposed in the track at a head of each recording unit at the dropout portion and the medium is divided into a plurality of zones in a radial direction with a length of a circular arc being substantially the same between the zones in a circumferential direction. At least two adjacent units in the radial direction of the medium comprise one zone. The method includes providing the optical medium, and recording information on the optical medium by irradiating an optical spot thereon.

Abstract: A recording method for an optical medium having a disk-like substrate, a plurality of tracks extending in a circumferential direction on the substrate and associated with a plurality of grooves, and a plurality of zones being provided on the disk-like substrate and extending between a first position and a second position in a radial direction of the substrate. Each zone including at least two tracks, and each track being divided into a plurality of units of circular arc shape extending in the circumferential direction with radially adjacent units of a respective zone being delimited by a pair of radial lines joined to form a central angle at an apex proximate to a center of the substrate. The method includes providing the optical medium, and recording information on the optical medium by irradiating an optical spot thereon.

Abstract: An apparatus for reproducing information recorded on an optical recording medium, including a disk-like substrate, a spiral or concentric-shaped groove structure along tracks formed on the substrate, each of the tracks being divided into a plurality of recording units. Each of the recording units includes a dropout portion in a circumferential direction of the groove structure with the dropout portion being a non-groove portion. The groove structure is formed with a wobble in a fixed cycle in a radial direction which continues in the circumferential direction along the track. Each length of the recording units is an integer multiple of the cycle of the wobble. The apparatus includes an irradiation source for irradiating a light spot on the medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the optical detector.

Abstract: An information reproducing apparatus for reproducing information recorded on an optical recording medium including a disk-like substrate, a plurality of tracks extending in a circumferential direction on the disk-like substrate and associated with a plurality of grooves wobbled in a radial direction, and a plurality of zones provided on the disk-like substrate and extending between a first position and a second position in a radial direction of the disk-like substrate. The information reproducing apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the optical detector.

Abstract: In a DVD-R, lands 1 and grooves 2 are alternately formed in a spiral configuration; the lands 1 form projecting parts, and the grooves 2 form recessed parts 2. Recorded information is written into the grooves 2, while land pre-pits 3 are formed in some portions of the lands 1. The land pre-pits 3 form recessed parts, and the respective land pre-pits 3 cover the entire width of the corresponding land 1 as shown in the figures. These land pre-pits 3 are arranged so that a>b>0.5×a, where a is the maximum length of the land pre-pits, and b is the minimum length (ordinarily, the minimum length is the shorter of the lengths b1 and b2 of the land pre-pits in the circumferential edge portions of the lands (i.e., the boundary portions with the grooves)). Furthermore, the value of a is set at 0.2 ?m to 0.4 ?m.

Abstract: An optical disk device for writing data onto an optical disk having a wobble track comprises an optical pickup for irradiating laser light of a writing power and laser light of a replaying power onto an optical disk and for converting return light from the optical disk into an electrical signal, a filter for extracting a wobble component contained in the return light signal when the laser of a writing power is irradiated, a processor for detecting the direction of track deviation based on the phase of the wobble component, and an actuator for driving the optical pickup in the width direction of the track based on the direction of the track deviation in order to control the tracking. Because the phase of the wobble component differs for a case when a light spot is deviated radially inward and for a case when a light spot is deviated radially outward, the direction of the track deviation can be detected based on the phase of the wobble component and the tracking can be controlled during data writing.

Abstract: An apparatus which records/reproduces data with respect to an optical recording medium, includes a data processing unit which detects a phase difference between a phase reference signal and a groove wobble signal detected from the optical recording medium, and compensates for the phase difference and performs a signal processing to record data on or reproduce data from the optical recording medium in response to the phase difference being equal to or greater than a predetermined reference value. By detecting a phase difference between a phase reference signal and a wobble signal and compensating for the phase difference, a recording of data on and a reproducing of data from the optical recording medium can be more accurately performed.

Abstract: A motor controller provides pulse width modulated drive signals to a motor. A digital demand code for controlling motor speed is input to the motor controller. A dither generator generates a digital dither value, which an adder adds to the demand code to generate a dithered demand code. A position determining circuit determines a rotational position of the motor. A pulse width modulation controller generates pulse width modulated drive signals with duty cycles controlled as a function of a stored set of waveform coefficients, the dithered demand code, and the rotational position of the motor.

Abstract: An information recording medium having at least a read only area and a recording and reproducing area is composed of at least: a substrate; a recording layer formed on the substrate so as to record and reproduce information; and a light transmission layer having transparency formed on the recording layer. The information recording medium is further characterized in that a wobbling groove corresponding to the read only area and another wobbling groove corresponding to the recording and reproducing area is formed on the substrate without overlapping with each other, the recording and light transmitting layers are continuously adhered over at least two areas of the read only area and the recording and reproducing area, reflectivity of the recording layer is more than 5%, and a push-pull signal output T3 reproduced from the read only area and another push-pull signal output T4 reproduced from the recording and reproducing area before recording satisfies relations of T3?0.1, T4?0.1 and 1.5?T3/T4?0.5.

Abstract: An optical disc having marks for dispersed addresses that can be easily detected with high precision. A dispersed address comprises synchronization marks, positive marks, and negative marks. Synchronization marks, positive marks, and negative marks are formed along a groove as partial discontinuities or partial modifications in the wobbled groove.

Abstract: An information recording method for a recording medium including a spiral or concentric-shaped groove structure along tracks formed on a disk-like substrate, wherein each of the tracks is divided into a plurality of recording units. Each of the recording units includes a blank portion in a circumferential direction of the groove structure, the blank portion being a non-groove portion, the groove structure being formed with a wobble in a fixed cycle in a radial direction, the fixed cycle of the wobble continuing in the circumferential direction along the track, and each length of the recording units is an integer multiple of the cycle of the wobble. The method includes irradiating a light beam to the recording medium, and recording information to the recording medium.

Abstract: A recordable or rewritable optical disk device capable of reproducing a wobble signal accurately at a high S/N ratio to thereby get address information even at a time of high-speed recording is disclosed. An optical disk is formed with wobbled guide tracks, and the light reflected from the optical disk is picked up by an optical pickup unit, which supplies corresponding electric signal to a wobble signal reproducing section. In the wobble signal reproducing section, at a time of recording, the input signal is sampled not only during a period of reproducing power and also during a period of recording power, and the two sampled signals are added to reproduce a wobble signal. The sampling during the period of recording power may be carried out within a period where the quantity of reflected light is in a stable condition after a pit is formed on the optical disk.

Abstract: An optical disk drive capable of securing reliable reproduction of a wobble signal even under a constant angular velocity control of a recordable or rewritable optical disk is disclosed. The optical disk has a guide track wobbled to produce a constant frequency when the optical disk is driven under a constant linear velocity control. An optical pickup unit detects the light reflected from the optical disk, and a wobble signal reproducing section takes out a wobble signal. The wobble signal reproducing section has two band-pass filters; a first band-pass filter detects a center frequency of the wobble signal, which is caused to vary under the constant angular velocity control, and a second band-pass filter has a center frequency set to the detected center frequency whereby the wobble signal is extracted by the second band-pass filter. The extracted wobble signal is subsequently demodulated address information.

Abstract: An optical disc recording method, an optical disc recording apparatus, and an optical disc in which performances of the optical disc is maintained over a long period of time without generating abrupt changes in wobbling curve of grooves of the optical disc. A phase modulation signal S4 is generated with abrupt changes in the waveform thereof at a phase transition point p being removed in accordance with a channel bit signal S3 including address signal, and the groove is made wobble in accordance with said phase modulation signal S4.

Abstract: Disclosed herein is a disc drive apparatus for recording and reproducing data to and from an optical disc-like storage medium. The apparatus includes a wobble signal generating element for generating a wobble signal representative of information about the wobble detected based on reflected light from the optical disc-like storage medium, and a land/groove detecting element for determining, when the light beam fails to trace a specific track correctly on the storage medium, whether the emitted light beam is located on a land field or in a groove field. The land/groove detecting element further outputs a land/groove detection signal having a waveform inverted depending on whether the light beam is located on the land field or in the groove field.

Abstract: A record carrier has a servo track (4) indicating an information track (9) intended for recording information blocks. The servo track (4) has a periodic variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information at regular intervals. The modulated parts start with a bit sync element and are of a data type having a data bit element, or of a word sync type having a word sync element. The word sync element and the data bit element are modulated according to a same predetermined type of modulation of the periodic variation. The effective strength of a modulated element is the number of periodic variations that are substantially different and available for detection of that element. The effective strength of the word sync element and of the data bit element are equal.

Abstract: In an optical disk recording device for projecting a recording light beam onto an optical disk to form 3T-11T pits in a land of the optical disk, timing to sample and hold a reflected light detection signal for tracking servo control is delayed behind timing to sample and hold the reflected light detection signal for wobble signal detection. Further, a sample-and-hold time period of the reflected light detection signal for tracking servo control is set to be shorter than a sample-and-hold time period of the reflected light detection signal for wobble signal detection. Such arrangements permit appropriate recording, even at high recording speeds, irrespective of residual optical axis deviations.

Abstract: Disclosed is a grooving apparatus which can carry information on an information track at high recording density when carrying the information on the information track through a change in shape of a groove and which also can improve the signal-to-noise ratio of the information under reproduction. A grooving apparatus for forming a groove to function as an information track in an optical disk comprises an electron beam generator which emits an electron beam, an objective lens which focuses the emitted electron beam on the optical disk and which focuses the electron beam on a smaller range than the size of the groove, and an X-direction deflector and a Y-direction deflector which controls the electron beam so that the electron beam is focused in position on the optical disk, thereby forming the groove in the optical disk.

Abstract: A recording medium that is adapted to maximize the recording capacity and to simplify the configuration of an information recording/reproducing apparatus including a pickup. In the medium, a different type of wobbling signals are preformatted in each of the adjacent land and groove signal tracks. A same-phase wobbling signal provided by wobbling each side of the respective land and groove signal tracks in the same phase and a different-phase wobbling signal provided by wobbling each side of the respective land and groove signal tracks in a different phase are used as the different type of wobbling signals. The physical positions of all the land and groove signal tracks are indicated by the same-phase wobbling signal.

Abstract: An optical disc having marks for dispersed addresses that can be easily detected with high precision. A dispersed address comprises synchronization marks, positive marks, and negative marks. Synchronization marks, positive marks, and negative marks are formed along a groove as partial discontinuities or partial modifications in the wobbled groove.

Abstract: A wobble detection circuit detects a signal by a common photodetector (light receiving) element from several kinds of media having different pre-formats. Further, the wobble detection circuit changes a gain for amplifying the signal in a wobble signal detection process depending on the pre-format of a reproducing or recording medium to obtain a wobble signal.

Abstract: A method for compensating track offset in an optical disk drive is provided, which achieves complete compensation of the track offset and than reduces the compensation time for the track offset. (a) An optical disk with wobbled grooves is provided, the wobbled grooves being used for generating a wobbling signal with a wobbling period. (b) A beat-inducing signal is recorded on the disk. The period of the beat-inducing signal has a specific relationship with the wobbling period in such a way that a beat signal is induced by the beat-inducing signal and the wobbling signal. (c) A tracking-error signal is generated using a push-pull method by optically reading the wobbled grooves of the disk and the beat-inducing signal recorded on the disk. The tracking-error signal contains a beat signal induced by the beat-inducing signal and the wobbling signal. (d) Track offset is compensated based on the beat signal contained in the tracking-error signal.

Abstract: The present invention provides an optical recording medium and an optical disk device realizing prevention of crosswrite and uniformity of playback signals and capable of easily securing compatibility with a read only disk. It provides an optical recording medium on which light LB condensed by a lens (12, 14) having a numerical aperture of 0.85±0.

Abstract: An information recording medium includes a substrate having a microscopic pattern which has a shape of continous substance of approximately parallel grooves formed with a convex shaped section and a concave shaped section alternating on a surface of the substrate, a recording layer that is formed on the microscopic pattern and a light transmitting layer having thickness of 0.05 mm. to 0.12 mm. that is formed on the recording layer. The microscopic pattern is formed so as to satisfy a relation of P??/NA, wherein P is a pitch of the convex shaped section or the concave shaped section, ? is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens. Further, the microscopic pattern has modulated address information formed on both side walls of the convex shaped section that is viewed from the light transmitting layer side as a wobble having same period and phase.

Abstract: An optical disc is described for recording data, which disc has a recording area for recording data encoded in optical marks at a recording density. The recording area has circular or spiral tracks provided with a servopattern comprising headers alternating with track portions. The headers contain position information encoded in preformed marks. The track portions comprise periodic characteristics, e.g. a wobble, to synchronise the data writing and reading operations. For reliably detecting the headers the phase of the periodic characteristics comprises a phase jump at a predetermined distance before each header.

Abstract: A recording medium having wobbled groove tracks out of phase with wobbled land tracks, a servo controlling apparatus using a wobble signal and a method thereof. The recording medium has land tracks and groove tracks, wherein both the land tracks and the groove tracks are wobbled, and wherein the wobbles of either individual groove tracks or individual land tracks are out of phase and the wobbles of the other type of individual tracks are in phase. Thus, it is possible to reliably address whether a groove (or land) track which is currently tracked by the pickup unit is a groove track or a land track, thereby ensuring addressing, and servo control can be effectively performed.

Abstract: A disc drive apparatus for recording or playing back data onto and from an optical-disc recording medium having a plurality of signal surface areas outputting detected information as reflected detection signals with different amplitudes, the disc drive apparatus including: reflected-light quantity detection means for detecting a total quantity of a light reflected by a signal surface of the optical-disc recording medium and outputting a reflected-light quantity detection signal representing the total quantity; integration means for integrating the reflected-light quantity detection signal and providing an integration output representing a result of integration of the reflected-light quantity detection signal; and identification-signal generation means for comparing the level of the reflected-light quantity detection signal with the level of the integration output used as a threshold value and for outputting an identification signal identifying a specific signal surface area among the signal surface areas as a

Abstract: The method of sampling wobble components of the present invention is capable of realizing a disk drive unit, which can write data at high speed, and reducing manufacturing cost of the disk drive unit. The wobble components are sampled from laser beams reflected from an optical disk so as to write data on the optical disk. The laser beams are low power laser beams for reading data and high power laser beams for writing data. The method is characterized in that the wobble components of the reflected low power laser beams and the reflected high power laser beams are continuously sampled.

Abstract: A tuned circuit is used to detect wobble clock inversions. The tuned circuit reacts to a wobble inversion with a change in amplitude that may be detected by a threshold detector. A bandpass tuned circuit is used to detect wobble clock inversions. The output of the bandpass tuned circuit is input to a saturating high-gain amplifier such as a comparator. The output of the saturating high-gain amplifier reacts to wobble inversions with a half-cycle that has an increased duration as compared to half-cycles without wobble inversions.

Abstract: Audio data of 20 bits is separated into first data of upper 16 bits and second data of lower 4 bits. EFM modulation data is formed from the first data. A laser beam is on/off controlled in correspondence to the logic level of channel data obtained by NRZI modulating a serial data train. The first data, therefore, is recorded in a manner similar to the case of a compact disc. Each pit is controlled so as to have a displacement in the right/left direction for the track center in accordance with the second data and the deviated pit is formed. When data is recorded by the displacement of the pit, since a high frequency component of a tracking error signal changes upon reproduction, the second data can be extracted from the tracking error signal.

Abstract: A physical identification data (PID) addressing method using a wobble signal, a wobble address encoding circuit, a method and circuit for detecting the wobble address and a recording medium therefor. Groove address information indicating physical identification information is phase modulated using a wobble clock signal and recorded in one of the two walls of a groove track, and land address information is phase modulated using a wobble clock signal obtained by shifting the phase of the former wobble clock signal and recorded in the other wall. That is, address information is phase modulated and recorded in each track using the wobbles having a phase difference of 90° between adjacent tracks so that a sum of wobble signals from the adjacent tracks can be a quadrature phase shift keying (QPSK) signal. Therefore, more data can be recorded in the recording medium, and since an interval in which a wobble signal disappears is not caused, recovery of a wobble clock signal can be advantageously performed.