Abstract: A method and apparatus for preventing a malfunction of a disc drive due to an operation error of a correction function for a minimum pit length by selectively performing the correction function based on an operative state of the disc drive. The method includes a first monitoring operation determining whether an operative state of the disc drive is stable when a disc is loaded into the disc drive, controlling a turning on of a correction function for a minimum pit length if the operative state of the disc drive is stable, and a second monitoring operation determining whether the operative state of the disc drive is stable after turning the correction function for the minimum pit length on and turning the correction function off if the operative state of the disc drive is determined to be unstable based on the second monitoring result.

Abstract: In an optical disc device comprising: a pickup 3 having a laser diode and generating a laser beam for recording onto an optical disc 1; a disc motor 2 that drives the rotation of an optical disc mounted thereon; a stepping motor that moves the pickup in the radial direction of the disc; and a system controller 6 that supplies drive current to the laser diode, and that controls the rotational speed of the disc motor and the position of the pickup by means of the stepping motor; the pickup has a temperature sensor 31 in its interior and system controller 6 restricts the drive current supplied to the laser diode in accordance with a detected temperature during data recording and controls the rotational speed of the disc motor, based on the detected temperature and the data recording properties of the optical disc which have been determined.

Abstract: A disc apparatus which enables an optical pickup to move swiftly to a target track is provided. A disc apparatus (1) includes an optical pickup (4) which irradiates an optical disc (2) with a laser light, a motor (6) which moves the optical pickup (4) to a target track in a radial direction of the optical disc (2), and a controller (7) which controls the motor (6). The controller 7 includes a calculating means (7a) which calculates a voltage level applied to the motor (6) and a recording unit (7b) which records a reference voltage level, a corrected number of tracks, and a coefficient. The calculating means (7a) calculates a voltage level based on the number of tracks between a track which the optical pickup is positioned over and the target track, the reference voltage level, the corrected number of tracks, and the coefficient.

Abstract: In order to make it possible to reproduce information recorded on an optical recording medium without causing deterioration in the information, a semiconductor laser driving device include a semiconductor laser, a photodetecting element for receiving a part of light emitted from the semiconductor laser and converting the part of light into an electric signal corresponding to a light amount; a laser driving circuit for inputting a driving signal into the semiconductor laser in such a manner that an average value of the electric signal coincides with a given target value, and a high-frequency superimposing control section for controlling an amplitude of the high-frequency signal. The high-frequency superimposing control section controls the amplitude in such a manner that a peak-to-average ratio that is a ratio of a peak value of the electric signal with respect to the average value of the electric signal does not increase above a given reference value.

Abstract: This invention provides an optical disc device that can prevent the occurrence of an error in a starting position of a write operation due to off-tracking, and to avoid an unnecessary stop of the write operation during writing. A tracking error signal generator generates a tracking error signal from a signal which has been detected by an optical pickup, and a system controller detects off-tracking by comparing the tracking error signal with a threshold level, and turns control operation of a tracking servo controller off if the threshold level is exceeded. The off-tracking detection threshold level applied during a time period from completion of seek operation to a start of movement of the optical pickup to the starting position of the write operation is set to be lower than a threshold level applied during a time period of data recording.

Abstract: A control circuit of an optical storage device includes a loop phase calculation unit for calculating a closed loop phase of a servo system according to at least one error signal of the servo system and a system control unit coupled to the loop phase calculation unit for generating an optimized control parameter according to the closed loop phase to perform compensation control, wherein the servo system comprises a tracking servo control system or a focusing servo control system, the compensation control is radial tilt control or focus balance adjustment, and the optimized control parameter is at least one optimized control parameter determined according to a plurality of closed loop phases calculated by the loop phase calculation unit.

Abstract: An optical disc system and a method of managing shock while recording or playing data in the optical disc system are provided. The optical disc system includes an optical pick-up unit for applying a laser beam to a track of an optical disc and detecting reflected light, a servo unit for controlling tracking and focus of the optical pick-up unit and a monitoring unit for comparing a monitoring signal, which is output from the optical pick-up unit and the servo unit, with a reference signal and generating a blocking signal and a blocking release signal. Recording or playing of data on the optical disc is stopped in response to the blocking signal, and recording or playing of the data on the optical disc is resumed in response to the blocking release signal based on a state of the optical disc system when recording or playing was stopped.

Abstract: The present invention is directed to an optical disc recording apparatus adapted for recording data onto a recodable/reproducible optical disc, which comprises a system controller (10) for executing finalize processing in the state divided into plural processing and memorizing, into a flash memory (16), a notification of completion of one processing every time the processing is completed.

Abstract: An information recording method records information in an information recording medium by acquiring driving power supply information related to a driving power supply of an information recording apparatus which records the information in the information recording medium, in response to a request for a process which accompanies recording of dummy data in the information recording medium, and determining whether to permit or prohibit the process which accompanies recording of the dummy data, based on the driving power supply information.

Abstract: An optical disc recording apparatus 100 comprises a temperature detecting circuit 141 for detecting a temperature of an optical disc 200 and corrects a laser power for discoloration a discoloration layer of the optical disc 200 in accordance with the temperature detected by the temperature detecting circuit 141 in order to cancel a change in the temperature of the optical disc 200. The optical disc recording apparatus 100 can record a high quality visible image on an optical disc without a printer.

Abstract: According to the present invention, it is intended that the recording can be executed normally even against small vibrations to which a servo error signal detecting circuit cannot respond. A recording apparatus according to the present invention includes an optical head (12) for receiving a reflected laser beam (LREF) obtained when a laser beam (LIRR) is irradiated on a CD-R (10). This recording apparatus further includes a gate circuit (31) to which an output signal (SRD) of the optical head (12) is supplied and a level comparing circuit (34) for comparing a value of an output signal (DTAU) of this gate circuit (31) with a predetermined reference value (DTH). Upon recording, the gate circuit (31) is controlled in such a manner that a signal of a predetermined period ts may be outputted from the output signal (SRD) supplied from the optical head (12) to the gate circuit (31) as the output signal (DTAU).

Abstract: The present invention provides a protection device and method of a read and write medium apparatus. When the read and write medium apparatus is operating, the protection device detects the external force and dynamically compels to cut the power supply off to remain the apparatus in non-operating condition. Besides, after the external force is withdrawn, the protection device can make the apparatus return to its prior operation operating condition. Thus, the invention enhances the shock-proof, drop-proof and collision-proof capabilities of the read and write medium apparatus and the protection thereof further.

Abstract: A method is described for setting an optimum recording power level for recording information on an optical record carrier. First a series of test patterns is written on the record carrier with a different recording power. On reading the test patterns, the jitter values of each read signal is determined. The jitter as a function of recording power is approximated with two linear functions. The optimum recording power level for the record carrier is derived from intersection of the functions. The invention relates also to a device arranged to perform the method. The invention further relates to an optical record carrier comprising the optimum recording power as determined by the method according to the invention.

Abstract: A motor control system comprises a motor controller and a clamp apparatus and is used for controlling a motor apparatus. The motor controller is used for generating a motor control output according to a reference signal and a feedback signal from the motor apparatus. The clamp apparatus is used for receiving the motor control output and has a clamp function for clamping the motor control output. The clamp apparatus determines whether the clamp function should be activated to clamp the motor control output within an acceptable clamp range according to at least one motor stability signal. When the motor stability signal indicates that the motor apparatus has been in a stable state, the clamp apparatus clamps the motor control output from the motor controller in the acceptable clamp range, so as to avoid an abnormal motor control output resulting from external sudden change.

Abstract: In a transient state in which the temperature difference of a drive device and a disk surface is great and the temperature of the disk surface changes successively, the issues of making a strategy suited to the temperature of the disk surface appropriate, making the irradiation angle of the laser light appropriate, and making the recording power level appropriate are regarded as problems requiring resolution. The aforementioned problems are solved by respectively detecting the temperatures of the drive device and the disk surface and, based on the same temperature difference, determining an appropriate strategy; and further by adjusting the laser light so as to irradiate at an angle appropriate to the inclination of the disk and irradiating the laser light on the disk; and determining an appropriate power level in response to the temperature of the disk surface.

Abstract: There is provided an optical disk drive capable of appropriately effecting recording and reproducing operations without being affected by offset values and a laser output value, which are set at startup of the disk drive, even when changes have arisen in the internal temperature of the disk drive because of changes in ambient temperature. In an optical disk drive, a temperature sensor provided on a pickup measures a temperature. When changes in temperature are greater than a predetermined level, a focus offset value, a tracking offset value, and a value of laser output from the pickup are reset.

Abstract: An optical recording/reproducing apparatus capable of backing up recorded information in case of an electrical power failure and a recorded information backup method thereof. Management information on recorded data is stored in a local memory such as a static random access memory (SRAM), when data is recorded into an optical storage medium. The management information is updated every predetermined period, and, if data for a corresponding title is completely recorded, the management information stored in the SRAM is recorded onto a certain area of the optical storage medium. If a power failure occurs during the recording of the data, a built-in battery operates and applies a predetermined voltage to the SRAM, so that the management information stored in the SRAM is maintained during the power failure.

Abstract: A disc type determining apparatus in a disc recording and reproducing apparatus in which vibrations generated by rotations of a disc occur in a focus and tracking control actuator includes an error gain adjusting unit, which adjusts an amplitude of a focus and tracking error in order to maintain a constant amplitude of the focus and tracking error; a loop gain adjusting unit which compares the closed loop phase of the focus and tracking control loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking control loop; a vibration measuring unit which measures vibrations using the adjusted error and the output of a controller; and a disc type determining unit which extracts a predetermined signal to determine the type of a disc using the measured vibrations, measures the deflection, eccentricity, and mass eccentricity of a disc using the extracted signal.

Abstract: A method of controlling recording of data with respect to each track of a once-writable optical disc, includes: detecting whether a shock error occurs during recording of track information; if the shock error is detected, stopping the recording of the track information and estimating a position where the recording of the track information has stopped; recording dummy data from a backward position behind the estimated position as much as a predetermined period of time, for a predetermined period of time; and defining an error track from a start position of a track to a position where the recording of the dummy data has ended.

Abstract: An optical storage device having a lens opposite to a storage medium comprises an actuator that moves the lens,a mechanical shock acceleration sensing means that senses a mechanical shock acceleration, a collision prevention control means that drives the actuator for a predetermined period of time with a first driving force greater than the maximum rating force of the actuator when the mechanical shock acceleration sensed by the mechanical shock acceleration sensing means becomes a value equal to a predetermined value, and then, that drives the actuator with a second driving force smaller than the maximum rating force of the actuator.

Abstract: An optical disk apparatus having a high reliability by evading collision between a condensing lens and an optical disk regardless whether the focus control is in the operative state or in the inoperative state, thereby preventing damage to the condensing lens and the optical disk. When the focus control is in the inoperative state, by using a reflection light amount from the optical disk (1), it is ascertained that the focus of the light beam is in the vicinity of the information surface and the condensing lens (15) is driven to be apart from the optical disk (1).

Abstract: A method and apparatus renders an optical disk unplayable on a customer's optical disc playback machine. A portion of the information bearing surface of the optical disc or the light reflected therefrom, is altered for data destruction from a predetermined area, i.e., a “Table of Contents” (TOC), in order to make the disc unplayable on the playback machine of the customer.

Abstract: A shock detector for an optical disc recorder and method for controlling the recording using a shock signal. The shock detector includes a first detecting unit for detecting the amplitude of a first kind of reference signal passing through a band-pass filter and outputting a first detecting signal, a second detecting unit for detecting the level of a second kind of reference signal and outputting a second detecting signal, a third detecting unit for detecting the revolution of a third kind of reference signal and outputting a third detecting signal, and a judging unit for receiving the first detecting signal, the second detecting signal and the third detecting signal, and enabling a shock signal when the first detecting signal, the second detecting signal and the third detecting signal are simultaneously enabled. Therefore, the shock detector does not need an additional shock sensor.

Abstract: A stabilization part stabilizes surface vibration of a flexible optical disk along a rotation axis direction of the optical disk by means of pressure difference of air flow created according to Bernoulli's law at a portion on which information writing/reading is performed, provided on a side of the optical disk opposite to a side on which information recording/reproducing is performed. In this case, areas are provide on the upstream side and down stream side along the disk rotation direction of the portion of the optical disk which is stabilized by said stabilization part, said areas of the optical disk not having pressure difference created thereon by the air flow.

Abstract: An optical disc drive apparatus (1) comprises: rotating means (4) for rotating an optical disc (2); a sledge (10) radially displaceable with respect to an apparatus frame (3); a platform (20) radially displaceable with respect to said sledge (10); an optical system (30) for scanning a disc, the optical system (30) defining an optical path (80) which is substantially fixed with respect to the sledge (10) and comprising an optical element (34) which is fixed with respect to the platform (20); an optical detector (35) fixed to said sledge (10); vibration detection means for detecting vibrations caused by the rotating disc; said vibration detection means comprising radial displacement detection means for detecting a radial displacement of said platform (20) with respect to said sledge (10).

Abstract: A controller for controlling interruptions and restarts when writing data to a recording medium by emitting a laser beam against the recording medium. The controller prevents buffer underrun errors. The laser beam is emitted at a high power level when writing data on the recording medium and at a low power read level when reading data from the medium. The writing of data is interrupted when there is a possibility of a buffer underrun error. When restarting data writing from where the interruption occurred, the laser beam is shifted from the read level to the write level before reaching the location at which the interruption occurred. This guarantees that the laser beam has the required power level when writing is restarted.

Abstract: An information recording apparatus includes: an information recording part performing information recording on a recording medium divided into a plurality of sectors each including a plurality of information units; a prediction part detecting or predicting an occurrence of a recording failure during the information recording; a suspension control part suspending the information recording at the present one of the information units of the recording medium and storing suspension information indicating a suspension position where the information recording is suspended; a determination part determining whether the recording failure is over after the suspension of the information recording; and a resumption control part causing the information recording part to resume the information recording at a position determined based on the suspension information so that information is continuously recorded on the recording medium over the suspension position.

Abstract: An optical disk apparatus is disclosed. A light emitting element emits a laser beam directed to a recordable optical disk. A driver rotates the optical disk. A first optimum recording power obtaining part performs test recording on the optical disk while the optical disk is rotated by the driver and output power of the light emitting element is varied so as to obtain an optimum recording power based on a reproduction signal in a test recorded area. A temperature measuring part measures the temperature in the vicinity of the light emitting element. A memory stores the optimum recording power obtained by the first optimum recording power obtaining part and the measured temperature when the optimum recording power is obtained. A temperature-dependent recording power obtaining part refers to the optimum recording power and the associated temperature stored in the memory so as to obtain an optimum recording power according to the temperature measured by the temperature measuring part in real recording.

Abstract: The present invention relates to a track access apparatus and a method by which an optical pick-up unit quickly accesses a destination track of an optical disc by controlling a tracking actuator using a back electromotive force by detecting the vibration of an objective lens, the position variation, and the distortion of an actuator which occur when the optical pick-up unit is moved across the tracks of the optical disc at a high speed.

Abstract: An optical disc system and a method of managing shock while recording or playing data in the optical disc system are provided. The optical disc system includes an optical pick-up unit for applying a laser beam to a track of an optical disc and detecting reflected light, a servo unit for controlling tracking and focus of the optical pick-up unit and a monitoring unit for comparing a monitoring signal, which is output from the optical pick-up unit and the servo unit, with a reference signal and generating a blocking signal and a blocking release signal. Recording or playing of data on the optical disc is stopped in response to the blocking signal, and recording or playing of the data on the optical disc is resumed in response to the blocking release signal based on a state of the optical disc system when recording or playing was stopped.

Abstract: An optical disk apparatus includes a rotary driving unit rotating an optical disk which is flexible, an optical pickup irradiating light upon a recording surface of the optical disk on which writing/reading of information is performed, a stabilizing unit stabilizing vibration of the optical disk in a rotary axial direction by using pressure difference of air flow at least on a portion where writing/reading is performed, and being disposed on a side of the optical disk opposite to a side on which the recording surface is provided, and a control-adjustment unit analyzing a value of a tracking error signal of the optical disk obtained by scanning along a groove of the optical disk with use of the optical pickup, comparing the analyzed value of the tracking error signal of the optical disk and a value priorly obtained by scanning along a groove of a standard disk prepared beforehand, and adjusting a positional relation between the optical disk and the stabilizing member in a three dimensional space according to t

Abstract: The present invention provides a control system of following a follow target position. A control system has a disturbance observer for obtaining a disturbance force estimation value and a speed estimation value as estimation values of a disturbance force and a speed as a speed to be controlled by using an actuator control signal cont and a zero follow position which can be observed. Since the disturbance force estimation value and speed estimation value are fed back.

Abstract: A data recorder for writing data to a recording medium that prevents buffer underrun errors. An optical head generates a laser beam at a high power level when writing data on the recording medium and at a low power level when reading data from the medium. The writing of data is interrupted when there is a possibility of a buffer underrun error. When restarting data writing from where the interruption occurred, the laser beam is shifted from the low power level to the high power level before reaching the location at which the interruption occurred. This guarantees that the laser beam has the required power level when writing is restarted.

Abstract: Provided are a method and apparatus for removing vibration due to the imbalance of weight of a disc in a disc drive, in which the allowable high multi-speed of a disc is determined based on the allowable amount of vibration in the disc drive and the disc drive is actuated within a range of the allowable high multi-speed. The method includes detecting the amount of vibration corresponding to the degree of imbalance of the weight of a disc inserted into the disc drive and increasing a set high multi-speed of the disc drive until the amount of vibration reaches an allowable amount of vibration with respect to the disc drive. Accordingly, vibration in a disc drive can be controlled such that a user cannot perceive it and damages to the disc drive due to the vibration can be minimized.

Abstract: An exposure apparatus for an optical disc used for eliminating the vibrations in the propagating direction when a rotation mechanism rotates. The slider controller 40 and the spindle controller 41 of the exposure apparatus 1 are activated, and the then the optical disc begins to be rotated by an AC synchronized motor. Through a condensing device 9, laser beams emitted form the laser source 6 are irradiated on the optical disc for exposure. At this time, the optical disc is eccentrically chucked on the rotation mechanism, resulting a rotational vibration of the whole rotation mechanism. A measurer 17 is used for detecting a propagating component of the rotational vibration, and a vibrator controller 42 controls the vibrator 20 as the output of the measurer 17 approaches zero. Therefore, the vibration in the propagating direction of the base 2 is cancelled, and the propagation accuracy is increased and the exposure quality is enhanced.

Abstract: A method and apparatus for controlling the power of a laser diode, which can prevent fluctuation in the laser power of the laser diode at a record/playback area of an optical disc. The apparatus for controlling the power of the laser diode includes a controller which controls an automatic power control of the laser diode (APC controller), interposed between an up/down counter and a laser diode driver, the APC controller latching the output of the up/down counter in synchronism with a periodic synchronization signal, and outputting the latch result to the laser diode driver. Therefore, the power level of the laser diode can be periodically controlled according to subdivided control modes, so that the laser power level remains resilient to external noise, compared to a continuous control operation through the entire mode.

Abstract: Herein disclosed is a optical disc driving apparatus for driving an optical disc having a central axis, comprising: a turntable having a central axis, said turntable being adapted to retain an optical disc under the condition that said central axis of said turntable is axially aligned with said central axis of said optical disc; an optical pickup unit movable toward and away from said central axis of said turntable, said optical pickup unit being adapted to write or retrieve information from said optical disc retained by said turntable; a stepping motor having a plurality of coils; a detecting unit for detecting an exterior vibration while being vibrated in response to said exterior vibration; a driver IC for controlling said stepping motor to have said stepping motor assume two different operation states consisting of a first operation state to drive said stepping motor to ensure that said optical pickup unit is moved toward and away from said central axis of said turntable, and a second operation state to d

Abstract: There is disclosed an information storage apparatus in which even when a remaining power of a battery or a galvanic cell is low, an information recording medium can safely be removed. An MPU, a spindle motor driver, and a spindle motor constitute a decelerator for decelerating rotation of the information recording medium, and as a deceleration mode, a first deceleration mode with a relatively large power consumption and a second deceleration mode with a relatively small power consumption are used. The MPU monitors a voltage of a power supply line via a DSP, decelerates the rotation of the information recording medium in the first deceleration mode when the voltage exceeds a predetermined level, and decelerates the rotation of the information recording medium in the second deceleration mode when the voltage indicates the predetermined level or less.

Abstract: HDD boxes 831 to 83n are each incorporated with a secondary battery box 87, a non-isolated DC/DC converter 89, and an HDD 91. Logical circuit boards 851 to 85n are each incorporated with the secondary battery box 87, fast-transient-response-type non-isolated DC/DC converters 931 to 933, and a plurality of loads 951 to 953. Every secondary battery box 87 is provided with a charge/discharge circuit 97, and a plurality of in-line secondary batteries 99. In the HDD box, the output voltage from the secondary battery box 87 goes to an HDD 91 via the DC/DC converter 89. In the logical circuit board, the output voltage from the secondary battery box 87 goes to the corresponding loads 951 to 953 via the DC/DC converters 931 to 933. With such a structure, in a disk array apparatus, realized are higher energy efficiency and less space occupation through reducing power loss and optimizing power capacity setting for a backup power.

Abstract: According to the present invention, it is intended that the recording can be executed normally even against small vibrations to which a servo error signal detecting circuit cannot respond. A recording apparatus according to the present invention includes an optical head (12) for receiving a reflected laser beam (LREF) obtained when a laser beam (LIRR) is irradiated on a CD-R (10). This recording apparatus further includes a gate circuit (31) to which an output signal (SRD) of the optical head (12) is supplied and a level comparing circuit (34) for comparing a value of an output signal (DTAU) of this gate circuit (31) with a predetermined reference value (DTH). Upon recording, the gate circuit (31) is controlled in such a manner that a signal of a predetermined period ? may be outputted from the output signal (SRD) supplied from the optical head (12) to the gate circuit (31) as the output signal (DTAU).

Abstract: A disk drive capable of producing the effect of a balancer even in a variety of reproduction and recording speeds without causing problems owing to the balancer, comprising a balancer in which magnetic balls 1 movably accommodated inside a damper 6 cancel any imbalance amount of a disk 5, and a detection section 14 provided near the clamper 6 to detect the behavior of the magnetic balls 1.

Abstract: In a playback apparatus which plays back music in a plurality of audio formats, a control unit detects a voltage level of a power supply unit and restricts a playback of music in one of the audio formats, which requires power consumption whose amount exceeds a given value, when the detected voltage level is lower than a threshold value. Alternatively, the control unit restricts a playback of one of a plurality of pieces of music, which requires power whose amount exceeds a given value, when the detected voltage level is lower than a threshold value.

Abstract: An information recording medium conveyer is provided, which provides countermeasures against power interruptions with high reliability. When a power interruption occurs during a loading operation with a conveying roller, the first unloading operation is initiated. When the outputs from detection sensors satisfy a predetermined condition during the first unloading operation, the process is initialized to cause the conveying roller to initiate a re-loading operation, thereby loading an information recording medium into a tray. On the other hand, when the outputs from the detection sensors do not change in accordance with a predetermined sequence during the re-loading operation, the process initiates the second unloading operation.

Abstract: Systems and methods are provided through which the current to a spindle motor of the recording medium of a mass storage device is modulated to avoid anomalies in the operation of mass storage device and reduce power consumption. In the example of a disc drive, the current is modulated to prevent expected or predicted disturbances in the air bearing between a read/write head and the recording medium, and to reduce the power consumption when no disturbances are predicted or expected.

Abstract: An information recording apparatus includes: an information recording part performing information recording on a recording medium divided into a plurality of sectors each including a plurality of information units; a prediction part detecting or predicting an occurrence of a recording failure during the information recording; a suspension control part suspending the information recording at the present one of the information units of the recording medium and storing suspension information indicating a suspension position where the information recording is suspended; a determination part determining whether the recording failure is over after the suspension of the information recording; and a resumption control part causing the information recording part to resume the information recording at a position determined based on the suspension information so that information is continuously recorded on the recording medium over the suspension position.

Abstract: A shock detecting apparatus has a sensor which detects a shock received by an apparatus that is provided with the shock detecting apparatus, a first memory which stores a first threshold value for detecting reception of a shock that cannot guarantee the function quality of the apparatus, but can enable operation of the apparatus, a second memory which stores a second threshold value larger than the first threshold value for detecting reception of a shock that disables operation of the apparatus, a third memory which stores information concerning a shock, a control unit which compares the magnitude of a shock with the first and second threshold values when the sensor detects the shock, and controls to store the information in the third memory according to the comparison result, and a battery which supplies power to the sensor and control unit even if power is not supplied from the apparatus.

Abstract: A method for determining an optimum writing power of a compact disc drive includes representing the relationship between a target read-back signal parameter and writing power as a polynomial function, which is stored in a database. The optimum writing power is obtained after at least one iteration of a writing test procedure. The test procedure includes utilizing a constant writing power.

Abstract: The invention provides an apparatus for reproducing a plurality of image data which has been recorded in a plurality of independent areas on a disk-shaped recording medium and specified so as to be reproduced in predetermined order, from the disk-shaped recording medium by using a pickup mechanism. The apparatus has a memory for storing the reproduced image data and a memory control unit for reading out the image data stored in the memory in the predetermined order, and controls whether the image data recorded in the plurality of areas is reproduced in order different from the predetermined order and written in the memory or not, on the basis of position information indicative of positions of the plurality of areas on the disk-shaped recording medium, a capacity of the memory, and a seeking time between the plurality of areas by the pickup mechanism.

Abstract: A control system for an optical disc for optical media with a premastered area that cannot be overwritten and a user-writeable area that can be overwritten, comprises a first processor operable to communicate with a second processor via a status register. The first processor sequences and monitors functions performed in the second processor and the second processor issues an interrupt when an error condition is detected in the second processor. The first processor detects the interrupt, and disables detecting further interrupts until the interrupt is serviced. Servicing the interrupt includes recording the error state and changing focus and tracking parameters based on the error condition detected.

Abstract: In a digital audio signal player having a simulated analogue record, a voltage dividing circuit is provided that consists of a first, and a second leads connected to a respective one of two separate wound wires of a control element; the control element can be turned to simulate an analogue record being moved by hands on the turntable for the player to play music with speed and speed changing according to movement of the control element. The microprocessor can decide that users' hands have touched the control element to complete the voltage dividing circuit, which is normally open, on detecting a voltage drop in order to make music played in the special mode. Music is played in an original normal way when the hand is removed from the control element for disappearance of the voltage drop.