Abstract: Systems and methods for providing audio-file loop-playback functionality are provided. The system includes a processor that performs a method including setting a playback loop start-point based on a first selection of a button; setting a loop end-point, associating a loop with an audio file, and entering into the loop based on a second selection of the button; and exiting the loop based on a third selection of the button. Associating the loop with the audio file includes adding metadata to the audio file. The metadata associates the loop with a button. The method includes reentering the loop based on a fourth selection of the button and exiting the loop based on a fifth selection of the button.

Abstract: The method adapted for a disc burner for sensing/computing the maximum allowable capacity of a disc for overburn purpose where an accurate capacity of the disc based on the outermost-edge wobble signal is obtained, resulting in more data written on the disc with an amount of the data smaller than the physically-recordable maximum capacity of the disc and decreasing the failure rate of data overburning.

Abstract: A wobble determining apparatus is provided with: a calculating device for calculating (i) a first time required until reaching a number of revolutions of a motor which allows a predetermined linear velocity, and (ii) a second time required to move an optical head to a position which allows the predetermined linear velocity, on the basis of the number of revolutions of the motor and the position of the optical head; a judging device for judging whether to keep the optical head in accordance with the calculated first time and the calculated second time; and a controlling device for controlling a moving device not to move the optical head if it is judged to keep the optical head, and for controlling the moving device to move the optical head to the position which allows the predetermined linear velocity if it is judged not to keep the optical head.

Abstract: An optical pickup includes a plurality of light sources, an objective lens, a diffractive optical element, and a light-detecting unit. The various light sources emit light of wavelengths that are different from each other. The objective lens focuses light on an optical disc. The diffractive optical element includes a diffracting portion and a light-blocking portion. The diffracting portion diffracts return light reflected from a first recording layer of the optical disc where information is being read or written. The light-blocking portion blocks stray light reflected from a second recording layer of the optical disc that is different from the first recording layer. The light-detecting unit receives the diffracted light of the diffractive optical element and generates an output signal to generate a tracking error signal based on this diffracted light. Furthermore, the light-blocking portion includes a plurality of light-blocking patterns which block light of wavelengths that are different from each other.

Abstract: Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.

Abstract: A control mechanism may control the height and/or position of a read/write head configured to interact with a rotating information storage surface. A topography detection mechanism may detect topography of a side read/write track while the read/write head is interacting with a current read/write track. A memory may store the detected topography. The control mechanism may adjust the height of the read/write head based on the stored topography. The topography detection mechanism may compute the detected topography from gap measurements using a dynamic filter including a model of read/write head dynamics. The control mechanism may be a reactionless control mechanism configured to apply a counterforce to offset movements of the read/write head and/or a slider.

Abstract: A position control method of an optical pickup head of an optical disc drive is provided. The optical disc drive has an optical pickup head for reading data from an optical disc and a step index for controlling the movement of the optical pickup head. The position control method includes: calculating a first position information of the optical pickup head according to the step index; reading an address information from the optical disc, calculating a second position information of the optical pickup head according to the address information; determining whether a difference between the first position information and the second position information is greater than a predetermined value; updating the step index when the difference is not greater than the predetermined value; moving the optical pickup head to an initial position when the difference is greater than the predetermined value, and setting the step index as zero.

Abstract: A recording medium, an address generating method, an address detection method and a recording and reproduction apparatus capable of extending the wobble address without any considerable wobble restructuring are disclosed. Virtual bits not recorded in the disc and expressed by the difference of the rule or the presence or absence of the information embedded in a part or the whole of the wobble address are generated. Thus, the extended address can be obtained without changing the number of bits of the address embedded in the wobble.

Abstract: There is provided an optical disk drive that pursues power saving and simultaneously assures data recording quality. A servo processor of the optical disk drive has a low frequency equalizer, a high frequency equalizer, a limiter, and an adder. A limit voltage value of the limiter is set by means of a control command from a system controller. The limit voltage value is set so as to become greater during a data recording period than in a data regeneration period. An output from the adder is supplied as a tracking drive signal to a tracking actuator or as a focus drive signal to a focus actuator.

Abstract: A data protection system includes terminals, and an encryption device that encrypts distribution data distributed to each terminal. Each terminal corresponds with one node on a lowest level of a tree structure having hierarchies. A data protection system excludes nodes on the lowest level, determines a plurality of combination patterns that include combinations of two or more of all four nodes that are reached one level below the node, decides an individual decryption key for each determined combination pattern, and decides an individual decryption key for each node on the lowest level. The data protection system prescribes nodes that are reached from the node on the lowest level and a terminal to the node on the highest level that is an invalid node.

Abstract: There is provided an optical disk drive that pursues power saving and simultaneously assures data recording quality. A servo processor of the optical disk drive has a low frequency equalizer, a high frequency equalizer, a limiter, and an adder. A limit voltage value of the limiter is set by means of a control command from a system controller. The limit voltage value is set so as to become greater during a data recording period than in a data regeneration period. An output from the adder is supplied as a tracking drive signal to a tracking actuator or as a focus drive signal to a focus actuator.

Abstract: For programs selected as those whose label is to be created, a list of available templates is displayed on a arrangement processing screen 200 together with contents of EPG information acquired from an EPG information DB. The EPG information is displayed on a left screen 210 and the templates list is displayed on a right screen 220, so that one template desired to be applied is selected on the right screen 220, according to which template, one or a plurality of the EPG information pieces whose label is desired to be created is selected on the left screen 210. Templates 230, 240, 250, and 260 constitute a label set comprised of a plurality of labels, thus enabling creating labels by incorporating information pieces of specified items.

Abstract: A drive apparatus of the present invention includes a recording/reproduction section and a drive control section. The drive control section at least performs a process including: allocating a contiguous area to a specific location in the user data area other than the location specified by the recording instruction; controlling the recording/reproduction section to record the data in the allocated contiguous area; and generating new disc management information including first replacement management information for mapping a start location of the contiguous area specified by the recording instruction to a start location of the allocated contiguous area and second replacement management information for mapping an end location of the contiguous area specified by the recording instruction to an end location of the allocated contiguous area.

Abstract: Disclosed is a system for generating an output signal indicating a specific area on an optical disc. The system includes an optical pick-up head signal generator, a detecting apparatus, and an output signal generating apparatus. The optical pick-up head signal generator is used for generating an optical pick-up head signal. The detecting apparatus is used for detecting pre-recorded address information on the optical disc to generate a detection signal. Also, a output signal generating apparatus, which is coupled to the optical pick-up head signal generator and the detecting apparatus, is used for receiving the optical pick-up head signal and the detection signal to generate the output signal according to at least one of the optical pick-up head signal and the detection signal, the output signal generating apparatus not generating the output signal according to the optical pick-up head signal after a predetermined time.

Abstract: A holographic recoding medium is provided, having holographic pages. Each page has reference mark (RM) placement areas at fixed locations for placing RM patterns. The reference marks are used to calibrate data images of data areas each of which is enclosed by at least three RM regions. Hidden information of the medium is stored by an specific encoded pattern based on existence, types and arrangements of the RM marks.

Abstract: The object of this invention is to provide an optical disc apparatus and an optical disc reproducing method that can realize an excellent reproducing operation by suppressing noise in the optical disc apparatus using an optical attenuator. In order to solve this object, a control voltage of the optical attenuator is changed according to reproduction power when reproducing the optical disc and an ambient temperature of the optical attenuator. In addition, the amplitude of a high frequency current for driving a laser diode is changed according to an attenuation factor of the optical attenuator.

Abstract: A laser power controller includes a loop control section to control a laser light output level of an optical head that applies laser light onto a disk for recording data to be a prescribed value, a DAC control section to hold as a previous level a laser control level preceding switching of a laser output level upon track change between a groove track and a land track during recording, and an analog SW to select the DAC control section to control the laser light output level by the previous level for a certain time period from the track change and to select the loop control section after the certain time period.

Abstract: An apparatus includes a moveable arm for positioning an optical transducer adjacent to a storage medium, a light source, and an elliptical or ellipsoid shaped mirror mounted for reflecting light from the light source to the optical transducer. The elliptical mirror can be positioned on an ellipse, the moveable arm can pivot about an axis passing through a first focus of the ellipse, and the light source can direct light from a point on a second axis passing through a second focus of the ellipse to the elliptical minor. The light source can include a fixed laser and a moveable mirror mounted to pivot about the second axis or a moveable laser mounted to pivot about the second axis. A method performed by the apparatus is also provided.

Abstract: A light beam is scanned on a track of a recording medium, the track having a first track region and a second track region, each track region having a physical property that has recurring deviations. A wobble signal is derived from the light beam, the wobble signal having information associated with the recurring deviations. Whether the light beam is at the first track region or the second track region is determined based on a frequency, a period, or a pulse width of the wobble signal.

Abstract: A recording device including a beam deflection section for relatively moving an irradiation position of an exposure beam with respect to a substrate on which a resist layer is formed; a substrate velocity adjustment section for adjusting a moving velocity of the substrate based on a deflection amount of the exposure beam; and a deflection control section for controlling to change a deflection velocity of the exposure beam during exposure of the recording signals according to the moving velocity of the substrate.

Abstract: As an optical disc is being rotated within an optical drive, an optical mechanism of the optical drive traces a discrete spiral path relative to the optical disc. As the discrete spiral path is traced by the optical mechanism of the optical drive, the optical mechanism selectively writes to the optical disc.

Abstract: An optical disk writing apparatus enhances writing accuracy by writing first data (e.g., test data) that encodes a first writing strategy within first patterns on an optical disk, in response to a first writing signal. A reproducing signal is generated in response to reading the first data from the optical disk. Variations between leading and trailing edges of the first writing signal and leading and trailing edges of the reproducing signal are detected. A correction value is determined using a jitter evaluation function to evaluate the detected variations. From these operations, a second writing strategy is determined using the correction value to modify the first writing strategy. Thereafter, second data (e.g., actual data) is written, which encodes the second writing strategy within second patterns on the optical disk.

Abstract: The determination on the reach to a BCA by using a pull-in signal in a seek for the BCA may eliminate the necessity of a position sensor for determination of the reach to a BCA, for example, which can realize a seek independent of a count of the number of steps by a stepping motor, for example. Thus, the construction can be simplified, and the costs can be reduced. Furthermore, the required accuracy of disk chucking and mechanical accuracy of the mechanisms may be alleviated, which can provide simplicity in design and manufacture. The pickup unit can be allowed to perform the secure reading of information in a BCA by, after the transporting unit is stopped based on the determination on the reach to the BCA, monitoring the determination results (determination signals) based on a pull-in signal, for example, with the objective lens at different positions and controlling the position of the objective lens to an optimum position.

Abstract: In a case where an image of a density that is uniform over a substantially whole area of an optical disc (200) is to be formed, a servo circuit (138) controls the rotation speed of a spindle motor (130) to be constant, and an ALPC circuit (162) controls the current level of a drive signal Li so that the laser power is constant. In this case, a main control section (170) sets the movement distance of an optical pickup (100) to be larger in the inner peripheral side where the line width of the image is larger, and that of the optical pickup (100) to be smaller in the outer peripheral side where the line width is smaller. The main control section (170) sends to a the motor driver (142) instructions for moving the optical pickup (100) by a movement distance which is determined on the basis of the setting.

Abstract: In a case where an image of a density that is uniform over a substantially whole area of an optical disc (200) is to be formed, a servo circuit (138) controls the rotation speed of a spindle motor (130) to be constant, and an ALPC circuit (162) controls the current level of a drive signal Li so that the laser power is constant. In this case, a main control section (170) sets the movement distance of an optical pickup (100) to be larger in the inner peripheral side where the line width of the image is larger, and that of the optical pickup (100) to be smaller in the outer peripheral side where the line width is smaller. The main control section (170) sends to a the motor driver (142) instructions for moving the optical pickup (100) by a movement distance which is determined on the basis of the setting.

Abstract: An apparatus and a method determine an area of an optical disc in which an inner area and an outer area of the optical disc having an absolute time of 99 minutes are distinguished from each other by referring to a number of ATIP syncs. The method includes counting the number of ATIP syncs for one rotation of the optical disc at a current position of a pickup when ATIP information recorded on the optical disc indicates that the pickup is currently present in an area of the optical disk that is greater than or equal to 95 minutes; and determining the current position of the pickup by comparing the number of counted ATIP syncs with a reference number of ATIP syncs. Accordingly, time spent determining the area of an optical disc and accessing the optical disc is reduced.

Abstract: A method for generating a calibration value (TESC) for a tracking error signal (TES) in an optical disc drive (1) comprises the steps of performing a jump towards a target track of an optical disc (2) inserted in said optical disc drive (1); during at least a part of the jump, calculating the calibration value (TESC) as an approximation of the average of a plurality of tracking error signal amplitudes (TESA(i)) corresponding to a plurality of track crossings.

Abstract: An optical disc in which a physical address of each smallest recording unit and a recorded address increase or decrease on first and second recording layers, and a method of identifying the recording layers. Embodiments are provided for discs having first and second recording layers with a same or an opposite track spiral direction. Physical addresses of the smallest recording units and a recorded address are increased or decreased between an inner radius and an outer radius of a recording layer in a manner which enables a reproducing and/or a recording device to more rapidly reproduce and/or record data on the disc. A physical address of the smallest recording units on the first recording layer is made different from a physical address of the smallest recording units on the second recording layer.

Abstract: A method for determining the position of a pick-up head involves retrieving the respective parameter values relating to the linear velocity and angular velocity of the pick-up head at a certain place on the optical disk, and then calculating the ratio of the parameter value of the linear velocity to the parameter value of the angular velocity. Since the ratio is linearly correlated with the distance between the pick-up head and the center of the optical disk, the absolute position of the pick-up head can be determined, as far as its whereabouts is concerned.

Abstract: A method and device for determining the presence or absence of a disk and/or a disk size without using FG signals, are provided. The method includes placing a pickup at a first zone on the optical recording medium, the first zone located between an outer radius of a first recording medium type and an outer radius of a second recording medium type, where the outer radius of the second recording medium type is larger than the outer radius of the first recording medium type; detecting a reflected signal based on a returned beam from the first zone of the optical recording medium; and determining at least one of a size and an absence of the optical recording medium based on the detected reflected signal. Therefore, an FG sensor that is provided in a general disk device can be eliminated, thereby reducing the size and cost of a disk device.

Abstract: A settling judgment method judges whether an object is settled at a target position by using a settlement judgment formula set a slice value and number of continuous samples. The slice and number of continuous judgments of the judgment value of the settling judgment are judged by the slice value and number of samples which are set such that the maximum value of a maximum amplitude ratio (Rate), for each frequency of cyclic disturbance (Y), determined from the maximum amplitude values (Max1, Max2) of the judgment values when the cyclic disturbance is applied is contained within a predetermined position accuracy. Settlings can be judged at high-speed and accurately according to the settling judgment formula, and both an improvement of positioning accuracy and high-speed judgment can be implemented.

Abstract: A method is disclosed for positioning an optical labeling mechanism substantially close to a particular track of a labeling surface on an optical disk. The method can include the operation of positioning the optical labeling mechanism adjacent to the particular track. A further operation can be measuring a first surface texture of the labeling surface using the optical labeling mechanism. Another operation can involve positioning the optical labeling mechanism adjacent to a different track. A further operation can be moving the optical labeling mechanism from the different track toward the particular track location. Another operation can involve measuring a second surface texture of the labeling surface using the optical labeling mechanism. A further operation can be comparing the first and second surface textures to determine if the optical labeling mechanism is positioned substantially near the particular track.

Abstract: A method and device for searching a recording medium are provided. The recording medium has a management information area of which location information is overlapped with that of a program area. The method for determining an area on a recording medium having an overlapped time range between two areas reads a time address from a current position on the recording medium, obtains additional information from the recording medium or from a recording medium driving unit, if the read time address belongs to the overlapped range, and determines, based on the obtained additional information, to which one the areas the current position belongs. Therefore, it prevents wrong track jumps that are caused from time-overlapped areas on a capacity-expanded recording medium.

Abstract: A method of determining coordinates for a storage medium includes: determining diffraction data from a plurality of diffraction patterns corresponding to diffractive markers of the medium; and combining the diffraction data to determine composite coordinates for the medium. The composite coordinates may include three translational coordinates and three rotational coordinates. The act of determining diffraction data may include shining a plurality of beams on a selection of the diffractive markers, and measuring the corresponding diffraction patterns in one or more photodetectors to determine the diffraction data. In this latter case the photodetectors may be segmented. The act of combining the diffraction data to determine composite coordinates may include solving a matrix system that couples the diffraction data and the composite coordinates. Each diffractive marker may include a pit. The storage medium may include a holographic storage medium.

Abstract: Optical disc systems and methods for controlling movement of an optical pickup to an innermost perimeter of an optical disc using track information are provided. For example, an optical disc system includes an optical pickup that includes a tracking actuator, a focus actuator, and an objective lens and radiates a laser beam onto the optical disc to detect light reflected from the optical disc. The optical disc system also includes a radio frequency amplifier, a sled motor, a servo driver, and a servo signal processor that includes an optical pickup movement determiner and outputs a servo control signal, the optical pickup movement determiner determining from a track-related signal whether tracks are detected on the optical disc at a current position of the optical pickup and outputting a track determination signal indicating whether the optical pickup has moved to the innermost perimeter of the optical disc, based on the determination result.

Abstract: An apparatus to control a step motor in an optical disk driving system to move a sled which transfers a pickup unit, including a playing unit, a coarse search unit, and a driving unit. The playing unit generates a first step pulse at a first interval of time set by a disk speed according to a comparison between a sled control signal and a tracking driving signal in a playing mode with a predetermined threshold. The coarse search unit generates a second step pulse at a second interval of time stored in a table according to a number of motion steps and a motion direction corresponding to an amount of motion of the pickup unit due to operations in a search mode. The driving unit drives the step motor based on the first and second step pulses.

Abstract: A positioning control apparatus for controlling a moving member to trace the position of a target member which almost equally repeats the position shift at a predetermined period comprises a position detector for detecting a relative position error, a first adder for adding a delay signal and a position error signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output signal of the first adder at a period corresponding to the position shift of the target member, a second adder for adding the position error signal and the delay signal, a third adder for adding an output of the second adder and the delay signal via a filter, a compensating unit for performing the compensation for offset and/or the compensation for stabilization of the positioning control apparatus based on an output of the third adder, a drive unit for driving the moving member based on an output of the compensating unit, and a delay-amount setting unit for setting the amount of delay of a signal delayed

Abstract: An apparatus and method thereof detect a location of a pickup in an optical disc. A pickup reads and writes a signal from or to the optical disc. A spindle motor rotates the optical disc. A controller measures a rotational speed of the spindle motor to detect a current location of the pickup in the optical disc, wherein the pickup is determined to be located in an area of more than 90 minutes of the optical disc based on ATIP information recorded on the optical disc.

Abstract: During a normal operation, a tracking control signal from a tracking controller is supplied to an adder via a first switch and to a radial deviation component detector. The radial deviation component detector determines a radial deviation component EC of AC caused by radial deviation of an optical disk from the tracking control signal and supplied that component to the adder via another switch. For a track jump, the first switch is turned OFF, cutting off the tracking control signal. Thus, the radial deviation component EC and a jump pulse signal from a jump signal generator are added together by the adder. However, an offset of the tracking control signal TC detected by a DC component detector is further added. To avoid instability, the track jump is compensated so as to be normally carried out even if a DC offset is added to a tracking control signal.

Abstract: An optical disc reproduction apparatus is provided for permitting appropriate automatic adjustment to a servo control system, particularly a CD and a DVD-ROM having a BCA. A limit switch 24 is disposed in such a manner that it detects movement of an optical pickup 11 to a position which is located at a radius of 23.49 mm from the center. A system controller 22 moves the optical pickup 11 by 1.0 mm in an outer radial direction from the position detected by the limit switch 24, and reads a signal from an optical disc 5 at that position to carry out the automatic adjustment to the servo system, through a servo controller 21 and a feed motor 18. As a result, in the CD, a signal within a lead-in area thereof is used for and subjected to the automatic adjustment performed by the servo controller 21, while in the DVD-ROM, a signal in an outer peripheral area of a lead-in area having the BCA and in the vicinity thereof is used for and subjected to the adjustment.

Abstract: A mark detecting circuit that stably and reliably detects the marks for address information from an optical disk having tracks formed in a spiral shape and having waviness with a fixed period. In the land pre-pit signal extracting portion 12, by means of first bottom envelope circuit 32 with a high tracking speed, first bottom envelope signal Sbtm1 that represents at high sensitivity the bottom envelope of push-pull signal (SA+SB)?(SC+SD) is generated; and, by means of second bottom envelope circuit 34 with a low tracking speed, second bottom envelope signal Sbtm2 that represents at low sensitivity the bottom envelope waveform of push-pull signal (SA+SB)?(SC+SD) is generated. Then, with the signal, obtained by level shift treatment of said second bottom envelope signal Sbtm2 using offset circuit 36, used as threshold signal Sref, first bottom envelope signal Sbtm1 is converted to a binary form. And land pre-pit signal SLPP is extracted from push-pull signal (SA+SB)?(SC+SD).

Abstract: The invention is an offset setting system for an optical reading/writing apparatus having an optical pickup head reading/writing digital data under a predetermined velocity on an optical storage media. The apparatus sets the offset including a plurality of buffer blocks when the pickup head crosses storage tracks each time on the media and stop on a target storage track. The offset is to steady the pickup head to read/write data on a target block of the target storage track. A buffer time estimating module estimates an average time for the pickup head crossing a buffer block under a predetermined velocity, defining as a buffer time. The buffer blocks setting module records a steady time for the pickup head steadying to read/write data on the target block, and sets the number of the buffer blocks by a predetermined setting process in the offset based on the buffer time and the steady time.

Abstract: A disc device in which recording is possible in a basic recording area in units of a subarea and startable at any position. Even if the recording cannot help stopping due to some external cause during recording on a disc-type recording medium that basically employs real-time sequential recording, the recording is re-openable at the position where the recording stopped when the external cause has disappeared. The disc device includes a reference clock counter that starts to count at the starting point of each basic recording area reference clocks read from the disc, and an address memory that holds an address of the basic recording area under recording. When the recording is stopped due to some external cause, the count of the counter and the address held by the address memory at that time are saved.

Abstract: In a recording medium reproducing apparatus that can reproduce a recording medium such as a CD-R or CD-RW recording therein compressed audio data, a track number of three or more digits can be indicated using an existing display portion that is designed to indicate a track number in two digits. For this, the apparatus determines whether digital audio data to be reproduced is compressed audio data, and when it is determined to be the compressed audio data, the apparatus indicates a track number of the reproducing compressed audio data in a track number display area and a minute display area, a value of minute of a reproduction time of the compressed audio data in a second display area, and a value of second of the reproduction time of the compressed audio data in a frame display area.

Abstract: When data in a volume in the excess of a specification of a disc is recorded on an optical disc (D) (overburn recording), overburn area information indicating a position to terminate data recording is set in a volatile memory (333) of an optical disc recording apparatus (300). The optical disc recording apparatus records the data in an overburn area of the optical disc by referring to the overburn area information set in the volatile memory and terminate the recording of the data when the recording position in the current point in time agrees with the position to terminate recording indicated by the overburn area information that is set in a second storage area (333b).

Abstract: In an optical disk drive, in order to cancel a lens offset which may occur when performing a seek followed by a read, a seek position must be set several sectors before a target position for the read, resulting in a delay in access time. A lens offset amount is measured when a seek followed by read is started, and how many sectors before a read target position a seek position must be set is determined on the basis of two parameters, namely, the lens offset amount and a number of seek tracks. Thereby, an optimum seek position at which the lens offset is canceled can be set with no waste, resulting in an improvement in access time.

Abstract: A method for determining the position of an optic pick-up head and the device of the same are disclosed. The number of frames in certain section of the disk are used to determine the position of the optic pick-up head. The number of frames in inner section of the compact disk is smaller than that in the outer section. The disk is virtually divided into a plurality of sections, and number of frames within each section is defined. As a result, when the optic pick-up head is at a certain frame, the position of the optic pick-up head can be determined the number of frames in the section.

Abstract: A signal recording medium has a plurality of recording layers. Each recording layer has tracks for recording information. The tracks have a wobbling structure in which they are wobbled at different periods for the respective recording layers. Appropriate processing can be performed for a target recording layer by monitoring the wobbling period of the track.

Abstract: An information recording device is provided. The information recording device includes an end detecting unit, a timing management unit, an encoder, and the like. In a case in which the information recording device writes data having a fixed unit length on a recording medium by dispersing and rearranging the data based on a fixed rule, the end detecting unit detects an end location of data recorded on the recording medium. The timing management unit decides a starting location on the recording medium for dispersing and rearranging data based on the end location. The encoder disperses and rearranges additional data by starting from the starting location, and writes the additional data on the recording medium continuously from the end location.

Abstract: An optical disk apparatus comprising a reproduced signal detector which digitizes a reproduced signal from an optical disk, a broadband synchronizing clock signal generator for generating a synchronizing clock signal for use in reproducing data, a signal processor for processing signals, and a disk rotation controller for controlling the optical disk by switching control modes according to the reproducing position of the disk, that is, performing CAV control using the constant rotating velocity which is the same as the current rotating velocity in a range where the synchronizing clock signal generator allows a reproduced signal to be subjected to pull-in-synchronization, and performing CLV control so that the linear velocity is constant to minimize the pull-in-enable changes of number of revolutions in a range exceeding the pull-in-synchronization range, by which arrangement the amount of change of number of spindle motor revolutions when the reproducing position of the optical pickup changes is minimized, th