Abstract: Apparatuses and methods for certifying a magnetic recording disk (102) are disclosed herein, in a described embodiment, the apparatus (100) comprises a certifier head (104) for testing the disk's magnetic properties and a product head (106) for testing the disk's mechanical properties and the apparatus (100) is configured to enable simultaneous access to the disk (102) by the product head (106) and the certifier head (104). A method of upgrading a media certifier is also disclosed.

Abstract: There is disclosed herein a method and apparatus for centring a disk on a spindle, a spinstand and a method of testing with a spinstand. The method of centring includes attaching the disk to the spindle with a stick-slip clamp. A vector is determined by which the centre of the disk is displaced from the spindle axis and the vector is aligned with a movably mounted piezo actuator. A voltage is then applied to the piezo actuator to cause the piezo actuator to apply an impulse to the edge of the disk to cause the disk to slip in the clamp and reduce the displacement of the disk.

Abstract: An inspection method and inspection apparatus of a magnetic disk are provided. A gliding test and a certification test are performed at the same time by simultaneously moving a head for the certification test and a head for the gliding test with a heat distortion utilization mechanism (a micro thermal actuator) along a recording surface of the magnetic disk during rotation at a predetermined revolving speed. A flying height of the head for the gliding test is determined according to a revolving speed of the disk. When the flying height of the head for gliding test is determined according to the revolving speed at the certification test, the head for the gliding test is adjusted to a desired height by adjusting a variation of the heat distortion utilization mechanism disposed on the head for the gliding test. The gliding and certification inspections can be performed at the same time.

Abstract: A write-once disc includes: a plurality of update areas in which a predetermined kind of updated information is recorded; at least one main access information area in which main access information is recorded, the main access information indicating a final update area in which finally updated information is recorded among the plurality of update areas; and at least one sub access information area in which sub access information is recorded, the sub access information indicating a location of the finally updated information recorded in the final update area. Accordingly, an access time for reading a predetermined kind of information required to use the write-once disc can be reduced.

Abstract: The invention provides a method for identifying a disk type of an optical disk in an optical disk drive. First, a pickup head of the optical disk drive is moved towards the optical disk. A reflected signal is then observed as said pickup head of the optical drive is moving on the optical disk. A motion behavior is then detected from said reflected signal. A first period between motion initiation of the pickup head and a first peak occurrence of the power of the reflected signal is then determined, the first peak occurrence take places while the pickup head detects said motion behavior of said reflected signal is in accordance with a motion reflected by an polycarbonate layer of the optical disk.

Abstract: An information correcting method includes: detecting a first pattern in a radial direction and a second pattern formed obliquely to the radial direction on a track traversing the first and second patterns; counting number of the first pattern until the count value reaches number of the first pattern in one round of the track; generating a value incremented up number of the second pattern in the one round every time an interrupt associated with detection of the second pattern is generated as number of the second pattern; calculating an ideal number from a value obtained by multiplying the number of the second pattern until the number is counted by the counted number of the detected first pattern and a number set to the second pattern with reference to the second pattern formed at a present initial position; and correcting the generated number with the ideal number.

Abstract: A disc-shaped information recording medium includes a first recording layer (L0 layer) having (I) a first trial write area (101P-1) for trial write of first trial write information for calibration of the laser beam along the first track path (TP1) from the inner circumference toward the outer circumference and (II) a first recording area for recording the first recording information along a first track path (TP1), in this order from the inner circumference side. Furthermore, the disc-shaped information recording medium includes a second recording layer (L1 layer) having (I) a second trial write area (101P-2) for trial write of second trial write information for calibration of the laser beam along the second track path (TP2) from the outer circumference toward the inner circumference and (II) a second recording area for recording the second recording information along a second track path (TP2), in this order from the inner circumference side.

Abstract: A computing device and method determines a position of a disk when the disk works abnormally. The computer searches out problem disks by determining if each disk included in the just a bundle of disks (JBOD) works normally, and determining if the computer can obtain a serial number of each problem disk. The computer notifies a user of the order number of the problem disk and an order number of the JBOD, in response to a determination that the computer can obtain serial number of the problem disk. The computer obtains the order number of the problem disk by deleting the data of the disk that works normally from the disk table, and notifying the user of the order number of the disk and the order number of the JBOD, in response to a determination that the computer fails to obtain serial number of the problem disk.

Abstract: According to one embodiment, a disk drive is provided, which starts reading data at the head thereof, when a sync mark is detected. The disk drive has a read channel that generates a forced SM detection signal if the sync mark cannot be detected because of the occurrence of TA. The read channel starts generating the forced SM detection signal at the end position of a preamble, which is equivalent to the position of the sync mark.

Abstract: An optical recording medium provided with one or a plurality of recording layers includes an adjustment data recording area for recording therein adjustment data used for adjusting focus or spherical aberration of laser light used for recording/reproduction, the adjustment data recording area being disposed at a predetermined position on each of the one or plurality of recording layers, and a determination information recording area for recording therein determination information indicating whether or not the adjustment data has been recorded in the adjustment data recording area in each of the one or plurality of recording layers.

Abstract: An information recording device includes: a magnetic disk; an identify module; and a record module. The magnetic disk includes information tracks for recording information by a shingle recording method and an alternate track including an alternate sector for recording alternate information. The identify module is configured to identify a track group including the information tracks that includes update sectors for updating information and a defective sector. The record module is configured to perform recording for updating information on the identified track group without updating the alternate information of the alternate sector corresponding to the defective sector.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.

Abstract: An optical article comprising a mark disposed on the optical article; wherein the mark comprises an optical state change material; wherein the optical state change material undergoes a change in its optical state when exposed to an activation signal selected from one or more of a laser, thermal energy, infrared rays, X-rays, gamma rays, microwaves, visible light, ultraviolet light, ultrasound waves, radio frequency waves, electrical energy, chemical energy, magnetic energy, and mechanical energy; wherein the optical article is transformed from a pre-activated state to an activated state when an authorized activation method is used; and wherein the optical article is transformed from a pre-activated state to an incorrectly activated state when an unauthorized activation method is used. A method and a system for changing the functionality of the optical article are also provided.

Abstract: A multilayered optical disk an information recording method and information reproducing method utilizing the disk includes three or more recordable or rewritable information recording layers, which has, among the plurality of information recording layers, at least a first recording layer and a second recording layer located on a side nearer to a light incident surface than the first recording layer, and which respectively has a first test area configured by a plurality of segments in the first recording layer, a second test area configured by a plurality of segments in the second recording layer, and comprising a specific area in which there is recorded information used to determine whether or not the respective segments in the first test area can be used.

Abstract: A method for moving magnetic heads in a magnetic recording/reproducing apparatus, which comprises the steps of writing high-frequency signals in the magnetic recording/reproducing tracks; and then, either (i) conducting DC erasing or AC erasing to inspect extra pulse signals reproduced from the erased tracks, or (ii) inspecting concurrently occurring signals of missing pulse and spike pulse, which are reproduced from the written signals, whereby minute protrusions on a surface of the tracks were detected. Reading and writing of information are conducted while the magnetic heads are moved in a manner controlled so that reading and writing of information in specific tracks having defects is avoided. This method enhances reliability and life of the magnetic recording/reproducing apparatus.

Abstract: A multilayer optical recording medium having three or more information recording layers is irradiated with a laser beam, and a first signal obtained from the reflected laser beam is subjected to a frequency filter. A second signal obtained by filtration through a high-pass filter is used to evaluate the characteristics of the multilayer optical recording medium. In this manner, even in a multilayer optical recording medium having three or more information recording layers, the influence of the variation of the thickness and material of the information recording layers and the influence of the variation of the thickness of a spacer layer can be clearly determined and evaluated.

Abstract: A method of recording information on a recording medium. The method includes determining whether an amount of information recorded in a user data area is equal to or greater than a predetermined value when a finalizing process is performed on the recording medium. The user data area is an area of the recording medium and is used for information recording. The method further includes padding an area subsequent to an area of the user data area in which the information is recorded, by recording dummy information, if the amount of the information is less than the predetermined value, and recording management information for managing the dummy information as a file, in the user data area, for dummy information that has been recorded halfway, if the padding is interrupted.

Abstract: A system for altering a functionality of an optical article from a pre-activated state to an activated state, comprising an optical article comprising an optical data layer for storing data, an external radiation source for generating an external stimulus adapted to interact with the optical article, such interaction causing a change in optical accessibility of optically stored data, a directing material, wherein said directing material is for directing the external stimulus to selective portions of the optical article, thereby altering the functionality of the optical article from a pre-activated state to an activated state; a convertible element capable of responding to the external stimulus to irreversibly alter the optical article from the pre-activated state of functionality to the activated state of functionality, wherein said convertible element comprises a color-shift dye, a magnetic material, a thermo-chromic material, a magneto-optical material, a light scattering material, a phase-change material,

Abstract: According to one embodiment, a method of detecting contact of a magnetic head with a magnetic disk by changing the dynamic flying height of the magnetic head in a magnetic disk drive is disclosed. The method can detect a change in the rotational speed of the magnetic disk. The method can detect the contact of the magnetic head with the magnetic disk based on the detected change in the rotational speed.

Abstract: In a hard-disc drive, a defect region on the hard disc is classified as corresponding to either thermal asperity (TA) or media defect (MD) by generating two statistical measures. A first measure (e.g., ?1) is based on (i) the magnitudes of one or both of signal values (e.g., equalizer input or output signal values) and the corresponding expected values of those signal values and (ii) the signs of one or both of the signal values and the expected signal values. A second measure (e.g., ?2) is based on the magnitudes of one or both of the signal values and the expected signal values, but not the signs of either the signal values or the expected signal values. The two measures are then compared to determine whether the defect region corresponds to TA or MD.

Abstract: An LPP detection unit detects an LPP from a wobble signal. A correction unit obtains a difference set by performing processing of calculating a difference in signal level between an LPP-present sync pattern portion and a non-LPP sync pattern portion having the same polarity, and executes correction on an RF signal at a timing when the LPP is detected, by using the difference set. The LPP-present sync pattern portion is a sync pattern portion obtained when the LPP is detected at the timing of the sync pattern portion positioned at the head of a sync frame of the RF signal. The non-LPP sync pattern portion is a sync pattern portion obtained when no LPP is detected at the timing of the sync pattern portion of the sync frame. In the case of reproducing information recorded on a DVD-R/RW optical disk, the occurrence of errors due to the effect of the LPP can be reduced.

Abstract: Provided are a disk defect inspection method and apparatus. The defect inspection method includes; determining an independent recording density value for disk defect detection in relation to disk drive component factors excepting a disk of the disk drive, and performing a disk defect inspection using the independent recording density value for disk defect detection.

Abstract: An information recording medium, recording and/or reproducing apparatuses, and recording and/or reproducing methods which enable effective management of a last data recording address of a data area of the information recording medium. The information recording medium includes a data area for recording user data, temporary recording management information for managing a data recording status of the data area and temporary disc management information for managing the information recording medium, wherein the temporary disc management information includes first information regarding a last recorded location of data in the data area and second information regarding whether the information regarding the last recorded location is consistent with an actual last recorded location of the data area.

Abstract: An information processing apparatus which detects concomitant information associated with a time at which data satisfying a preset condition is supplied within a continuous period of time from input data that is temporally continuously input is disclosed.

Abstract: An optical disc verification method according to the present invention includes the steps of: writing data on first, second and third radial locations on an optical disc at a writing speed V1 and reading the data written there, thereby measuring read signal quality index values A, B and C, where the second radial location is inside of the first radial location and the third radial location is inside of the second radial location; writing data on the first and second radial locations at a writing speed V2, which is higher than V1, and reading the data written there, thereby measuring read signal quality index values D and E; and correcting the signal quality index value C with the difference between the signal quality index values B and E, thereby calculating a signal quality index value F that would be obtained if data is written on, and then read from, the third radial location at the speed V2.

Abstract: Provided is an optical disk device installed in a personal computer, including: an information creation unit that creates identification information for identifying the type of the personal computer based on a command transmitted from the personal computer; and a parameter selection unit that conducts switching, for parameter selection, concerning a parameter indicating an amount of unbalance of an optical disk, which has previously been determined depending on the type of the personal computer, in accordance with the identification information created by the information creation unit.

Abstract: A reference-capacity calculating unit calculates a reference capacity of each of storage devices storing therein data on the basis of an actual capacity of each storage device. A difference calculating unit calculates a difference value between the reference capacity calculated by the reference-capacity calculating unit and the actual capacity of each storage device. A maximum-value retrieving unit retrieves the maximum difference value out of the respective difference values of the storage devices calculated by the difference calculating unit. A defined-capacity determining unit determines a defined capacity, which is an actually-used capacity of each storage device, on the basis of a value obtained by subtracting the maximum difference value from the reference capacity calculated by the reference-capacity calculating unit.

Abstract: The effect of detection errors when detecting if a disc recording medium is in a disc drive is eliminated. A control unit 17 detects if an optical disc 11 was supplied to an optical disc drive 13 based on the operation of the transportation unit 16, causes the optical disc drive 13 to detect if an optical disc 11 is inside the disc drive, and compares the results of these detection operations. If the results do not match, the control unit 17 causes the optical disc drive 13 to repeat the operation discharging and loading the optical disc 11, and causes the optical disc drive 13 to again detect if an optical disc 11 is present after the discharge and loading operation. The control unit 17 then determines if the new detection result from the optical disc drive 13 and the detection result related to supplying the optical disc 11 to the optical disc drive 13 match, and based on the result of this evaluation detects an optical disc drive 13 operating error.

Abstract: An apparatus for optically checking magnetic disk defects that makes possible more accurate determination of positions of minute defects by illuminating an area greater than a checkup area with an illuminating beam having a Gaussian distribution is to be provided. The apparatus is configured of a specular reflection detecting device including a detector having a detecting face including an array of multiple pixels, and a processing device that figures out the position of each defect by using, in addition to the output signal from each of the pixels of the detector that detected a specular reflection from the checkup area, also output signals of some pixels out of the multiple pixels having detected the specular reflection from the checkup area of one turn before and the checkup area of one turn after, both adjoining in the radial direction, and determines the type of the defect.

Abstract: A tool for testing a magnetic disk for use in a magnetic disk drive. The tool detects surface defects or asperities by detecting a change in electrical resistance corresponding to a temperature change in a thermally sensitive layer. The apparatus includes a slider body having a thermally insulating layer formed on an air bearing surface of the slider body and a thermal sensor layer formed on the thermally insulating layer. The thermally insulating layer prevents thermal heat spikes in the thermal sensor layer (such as resulting from contact with an asperity) from dissipating quickly into the slider body itself. The thermal sensor layer is a material that exhibits a change in electrical resistance in response to a change in temperature and is preferably a PTC thermistor material which exhibits a large change in electrical resistance when a transition temperature has been reached.

Abstract: The present techniques provide methods and systems reading a data bit of interest on an optical data disc with a reduced error rate. The data bit estimation may be improved by reducing deterministic noise resulting from an optical reader system and/or the optical data disc. The reader may adjust the position of a detector to detect light scattered from the disc based on parameters of known noise sources. In one embodiment, the detector may be moved vertically in relation to the data bit of interest on the optical disc. In another embodiment, more than one detector may be used to detect light scattered from a data bit of interest. In embodiments, the positioning of the detector(s) may be based on system or disc parameters, and the detected scatterings may provide a data reading, improved for an optical return from a present micro-hologram.

Abstract: A method of detecting defects of a recording medium comprises detecting a number of error-corrected error correction code symbols in each of a plurality of sectors in the recording medium, classifying sectors having a number of error-corrected ECC symbols greater than a first threshold value as first type defect sectors, calculating moving averages of the numbers of error-corrected ECC symbols in units of a predetermined number of sectors, and classifying sectors that are used to calculate a moving average greater than a second threshold value as second type defect sectors.

Abstract: A method of managing a defect of a hard disk drive includes calculating a number of ECC symbols of every sector which becomes an object of a defect scan and setting a defect reference value based on results of the calculation. The hard disk drive sets a sector as a defect sector having the number of ECC symbols greater than a set defect reference value.

Abstract: In an optical disc having N (N is an integer larger than or equal to 3) information recording layers of rewritable or recordable type, each of the information recording layers includes an test area to adjust conditions for recording and reproduction and the test areas are arranged so that the radial positions thereof overlap those of other layers. Recording test is performed only to an area smaller than or equal to 1/N of the test area of each layer and any other area is always unrecorded (write inhibited).

Abstract: An information recording and/or reproducing apparatus capable of obtaining a certain recording/reproducing margin with a simplified structure. The apparatus identifies whether an optical disc is a single-layer recording medium having one recording layer, or a multilayer recording medium having a plurality of recording layers, and sets a control range (movable range) of an objective lens on the basis of the identification result. When the optical disc is identified as a multilayer recording medium, the control range of the objective lens is set to be smaller than that for a single-layer recording medium. Further, the control range of the objective lens is set for each of the recording layers of the optical disc.

Abstract: A data storage device determines a zone layout based on a quality evaluation factor. The zone layout is designed such that a measurement value of the quality evaluation factor for each track in each zone is within a range between a predetermined upper limit and a predetermined lower limit and a maximum amount of variation of the measurement value within each zone is substantially equal to a difference between the upper limit and the lower limit.

Abstract: In an image-recording device using a disk-type recording medium generated under the DVD+RW standard, a disk information-acquisition unit 250 acquires information about a disk 49, a disk-determination unit 260 determines that the disk 49 is a subject disk that is of a DVD+RW type and that stores video data generated by using a DVD menu and/or still-image data recorded onto the disk, an additional recording-control unit 220 controls additional recording performed for the disk 49 according to a result of the determination performed by the disk-determination unit 260, and a message display-control unit 270 makes a display unit 280 show a confirmation message used for shifting to a mode relating to the pros and cons of performing the additional recording and/or a message adapted to confirm that the DVD menu and the video data are updated, so that a mismatch which may occur between the DVD menu and/or the video data, and recorded image data is reduced.

Abstract: Disclosed is a magnetic recording medium evaluating method capable of providing a discrete-type or bit-pattern-type magnetic recording medium that has stable head floating characteristics even when concave and convex portions remain on the surface and can respond to high recording density with high productivity. A method of evaluating a magnetic recording medium having a magnetic recording pattern on at least one surface of a disk-shaped substrate and includes concave and convex portions corresponding to the magnetic recording pattern on the surface includes: floating and moving a head slider having a sensor attached thereto above the surface of the magnetic recording medium that is rotated; detecting a signal output from the sensor in a non-contact state between the head slider and the magnetic recording medium; and determining whether the magnetic recording medium is defective on the basis of the signal.

Abstract: An LPP detection unit detects an LPP from a wobble signal. A correction unit obtains a difference set by performing processing of calculating a difference in signal level between an LPP-present sync pattern portion and a non-LPP sync pattern portion having the same polarity, and executes correction on an RF signal at a timing when the LPP is detected, by using the difference set. The LPP-present sync pattern portion is a sync pattern portion obtained when the LPP is detected at the timing of the sync pattern portion positioned at the head of a sync frame of the RF signal. The non-LPP sync pattern portion is a sync pattern portion obtained when no LPP is detected at the timing of the sync pattern portion of the sync frame. In the case of reproducing information recorded on a DVD-R/RW optical disk, the occurrence of errors due to the effect of the LPP can be reduced.

Abstract: The present invention relates to a disk protrusion detection/flatness measurement circuit and a disk glide tester, in which protrusion detection and average value calculation can be performed without switching signal processing circuits of two systems, one for the protrusion detection of a disk and the other for the average value calculation with respect to a track or a sector of the disk. This also makes it possible to reduce the size of the measurement circuit. In the protrusion detection/flatness measurement circuit, a signal from a protrusion detection sensor is amplified and converted from an analog signal to a digital signal. The signal passes through a band-pass filter to obtain a digital signal with a predetermined bandwidth. Then, peak detection and average value calculation processes are applied in parallel to the obtained digital signal. Thus, pass/fail decision of the disk can be made based on the detected peak and average values.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the first light reflecting layer is smaller than the thickness of the second light reflecting layer.

Abstract: According to an embodiment, an apparatus for recording data in a recording medium, includes a reading/recording unit recording or reading data on or from the recording medium, the read data including a position information, the position information indicating a last recorded position and a recordable position for new data to be recorded; and a controller examining whether or not an area corresponding to the recordable position has an already recorded data, and determining whether to change the recordable position to another position for recording the new data based on the examination result, the another position being physically separated from the recordable position indicated by the read data recording information, wherein the controller identifies another position for recording the new data if the area has the already recorded data.

Abstract: A method for improving read stability of optical recording medium is disclosed. In the method, the thickness of a recording layer of an optical recording medium is adjusted to control the disc absorptivity, and the recording layer thickness is matched with a power difference between a laser write power (Pw) and a laser erase power (Pe), so as to control the optimal laser power for irradiating and accordingly changing the optical properties of the recording layer. It is found that by using properly increased recording layer thickness corresponding to a given disc absorptivity, and properly matching the recording layer thickness with a properly increased power difference, the read stability and recording characteristics of the optical recording media can be improved without significantly changing the layer structure and writing strategy of the optical recording medium.

Abstract: According to one embodiment, an error correcting circuit includes: a marker decoder configured to sample 2-bit markers from a data string and, from a plurality of sample values of the 2-bit markers, determine whether there is an occurrence of an error on the 2-bit markers, of an insertion error, or of a deletion error; and an error correcting module configured to perform first error correction on the data string received from the marker decoder by using an error correcting code in the data string. When either one of the insertion error and the deletion error is determined to have occurred, the marker decoder is configured to perform second error correction on the either one of the insertion error and the deletion error, and output the data string from which the 2-bit markers are removed.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.

Abstract: A method for determining a type of a disk and an optical storage apparatus thereof are provided. The method includes when the disk placed in the optical storage device is not a blank disk, determining whether the phases between a first signal and a second signal of the disk are the same or not; and determining that the disk is a low to high (LTH) data disk or a high to low data disk (HTL) data disk upon whether the phases of the first signal and the second signal are the same or not. Therefore, the reading parameters are correspondingly loaded in the optical storage device according to the type of the disk.

Abstract: A method for certifying data on tape cartridges for a library with a first tape cartridge that possesses a medium auxiliary memory device, a medium auxiliary memory reader/writer, a first tape drive and a second tape drive, a shelf system, and access to a memory device containing a media lifecycle management data base. After a period of time from when data was originally stored on the tape first cartridge, a portion of data residing on the first tape cartridge is read. The portion of data is assessed as to whether a percentage of the portion contains an expected data structure and if the percentage exceeds a predetermined threshold, a data recovery sequence is initiated.

Abstract: A rotation angle sensor includes a rotation shaft, a yoke which is made from a magnetic permeable material and includes a first disk portion, a second disk portion and a connection portion magnetically connecting the first disk portion and the second disk portion, the first disk portion and the second disk portion being provided on the rotation shaft in an axial direction of the rotation shaft separately, a permanent magnet which is provided between the first disk portion and the second disk portion, and has an annular shape, and a magnetic field detection section which generates an output signal in response to an intensity of a magnetic field formed by the permanent magnet during a rotation of the rotation shaft.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.

Abstract: A write-once read-many information recording medium is provided, which is capable of easily searching for a latest DDS and a latest defect list. At least one disc management working area is sequentially allocated in a predetermined direction on the write-once read-many information recording medium of the present invention. The latest defect list and the latest DDS are provided in a recorded disc management working area neighboring a border between the recorded disc management working area and an unrecorded disc management working area, where the latest defect list precedes the latest DDS in the predetermined direction.