Abstract: This invention achieves high-density recording while preventing recording units from overlapping. Recording is done to form a gap between predetermined recording units. Since this gap is formed, even when a rotation driving mechanism of a medium suffers rotation nonuniformity, two neighboring recording units never overlap each other, and destruction of recording data can be prevented.

Abstract: A disc apparatus is designed for recording a signal on an optical disc by irradiating an optical beam according to a strategy which is stepwise updated by a given step amount. In the disc apparatus, a detector successively detects a linear velocity of the optical disc relative to the optical beam in realtime basis. A strategy generator operates every time the detector detects the linear velocity of the optical disc for successively generating the strategy according to the detected linear velocity. A storage has a plurality of storage areas, each being capable of memorizing the strategy successively generated by the strategy generator. A write controller rewrites one of the storage areas every time the strategy is generated until the strategy is updated by a given step amount and then rewrites another of the storage areas every time the strategy is generated while leaving said one storage area to hold the updated strategy, thereby updating the strategy through the plurality of the storage areas.

Abstract: When the temperature of an SPM (spindle motor), measured by a temperature sensor, falls outside a predetermined temperature range, a CPU in a disk drive sets, in a disk controller, information concerning the activation of the SPM, to enable a host system to acquire the information. The information includes a temperature control request used to cause the temperature of the SPM to fall within the predetermined temperature range, the present temperature of the SPM and a waiting time required for the SPM to become activatable as a result of temperature control by the host system.

Abstract: A method for detecting the speed of a sledge motor in an optical storage device. In response to a track jumping command, a tracking servo output signal is expanded onto an orthogonal space to obtain simulation parameters corresponding to the tracking servo output signal. A pseudo-tracking servo output signal is generated according to the simulation parameters of the tracking servo output signal. Then, the pseudo-tracking servo output signal is used to compute the speed of the sledge motor.

Abstract: Methods and computer readable media with program instructions for dynamically determining write speeds of an optical media device are provided. In one example, a method includes setting a device set write speed to a maximum write speed of the optical media device, and then verifying that the device set write speed is as just set. If the optical media device is verified to be as just set, a current set write speed is saved. The device set write speed is then decreased by an increment and the device set. The device set write speed is again verified to be as just set, and saved if verified. The method continues to decrease the device set write speed by an increment, set, verify, and save until the device set write speed is set to zero. Only verified set write speeds are presented as options for user interaction for the optical media device.

Abstract: A device and method for calibrating linear velocity and track pitch for an optical disc is disclosed. The device comprises a frequency divider, a synchronous bit-clock generator, a counter and a linear velocity and track pitch calculator. The frequency divider receives a motor frequency generator (FG) pulse and generates a motor rotation period signal (FG/X). The synchronous bit-clock generator generates a high frequency bit-clock according to a reproduced signal read from disc. The bit counter counts the pulse of the bit-clock for each period of the motor rotation period signal to generate the data amount M. The linear velocity and track pitch calculator calculates the linear velocity by a linear velocity function with the information of the data amount M and the motor rotation period. Then, the linear velocity and track pitch calculator calculates the track pitch by a pitch function with the information of the data amount, radius and linear velocity at different tracks.

Abstract: Formatting is applied only to a local area which is a part of the entire recordable area of a rewritable disk and which does not include portions where a lead-in area and a lead-out area are to be formed. In other words, only the required minimum area is formatted. The formatted area is extended afterwards as required. Thus, disk formatting is shortened.

Abstract: A system and method for controlling operation of a motor system that addresses the design challenges for the small form factor optical disk system. The control system can be operable to detect a first BEMF crossing and setting a first time stamp, to detect a second BEMF crossing and setting a second time stamp, to calculate a measured spin period as the difference between the first time stamp and the second time stamp, to compare the measured spin period to a reference spin period to determine a period error, to operate on the period error with a proportional gain and an integrator gain to provide a command output; and to drive a winding in the spin motor with a current to cause the spin motor to change velocity in response to the command output.

Abstract: A read-only recording medium and a reproducing method thereof ensures reproduction compatibility with a rewritable recording medium in which real data is recorded with substantial discontinuity. The read-only recording medium comprises a data recording area in which real data is stored; and a plurality of waste areas allocated at intervals in the data recording area. The method of reproducing data stored in a read-only recording medium reproduces data from the read-only recording medium, skips if a waste area is encountered or removes invalid data reproduced from the waste area wherein each waste area has been inserted periodically in the read-only recording medium, and outputs the data reproduced before and behind each waste area in succession. As a result, the playability is improved in a disk device capable of reproducing both a read-only and a rewritable recording medium.

Abstract: The present invention provides a write-once optical information recording medium that can achieve a high reflectance and favorable recording and reproducing characteristics such that a high C/N ratio and high sensitivity even when information is recorded/reproduced with high density. This medium includes a transparent substrate and at least one information layer formed on the substrate. The information layer includes a recording layer made of a material including Te, O and M, where M is at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au and Bi. A reflectance with respect to a light beam incident from the side of the transparent substrate after recording information on the recording layer is lower than a reflectance before recording.

Abstract: A method for reading data from an unbalanced disk in a disk drive is disclosed. The method includes the steps of measuring a degree of unbalance of the disk while starting up a rotation of the disk, determining a suitable rotating speed for error-free reading (e.g., a maximum error-free reading speed) corresponding to the measured degree of unbalance, based on a previously stored relationship between degree of unbalance and suitable rotating speed, and beginning a reading operating while rotating the disk at the determined rotating speed. In accordance with the method, it is possible to suppress an unbalanced disk from vibrating, thereby achieving a stable data reading from the disk.

Abstract: A track jump apparatus for making an actuator jump in order to move a spot position of a laser beam emitted through an objective lens of the actuator from a current position to an object position corresponding to a desired recording track on a recording medium.

Abstract: Disclosed are an information recording method and an optical disk unit that maintain a good jitter even when a line velocity is variable in a mark edge system. In the case where an erasing power when erasing a record mark at a linear velocity v1 is Pe1(mW), a recording power when forming the record mark at the linear velocity v1 is Pw1(mW), an erasing power when erasing the record mark at a linear velocity v2 faster than v1 is Pe2(mW), and a power when forming the record mark at the linear velocity v2 is Pw2(mW), a relationship of Pw1/Pe1>Pw2/Pe2 is satisfied.

Abstract: A data recording device for recording data on an optical disc by irradiating a laser pulse on the optical disc while controlling rotation of the optical disc at a constant angular velocity. The device includes a laser condition varying unit that changes a peak value of the laser pulse in accordance with a value relating to a linear velocity of the optical disc at a position at which the laser pulse is irradiated.

Abstract: A motor controlling device includes an acceleration detector for detecting an acceleration of a motor; a motor driver for supplying a driving current to the motor; a heat quantity calculator for calculating a heat quantity generated in the motor at least based on an output from the acceleration detector; and a motor controller for controlling the motor driver based on the heat quantity.

Abstract: Method and apparatus for controlling high-speed rotation of optical disc, wherein the amount of disc vibrations caused by the disc rotation is calculated and the disc rotation speed is increased based on the calculated amount of disc vibrations to maximize the data transfer rate under given disc vibrations. The apparatus of the present invention comprises a pickup for retrieving data recorded on an optical disc, a drive unit for driving motors, an R/F unit for equalizing and shaping signals reproduced from the optical disc, a servo unit for controlling the drive unit and detecting sync signals from the output signal of the R/F unit, a digital signal processing unit for retrieving original digital data from the output signal of the R/F unit, a timer for measuring the elapse time between specific events, and a microprocessor for controlling the rotation speed of the optical disc based on the elapse time measured by the timer.

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: A system and method for controlling operation of a motor system that addresses the design challenges for the small form factor optical disk system. The present invention includes starting the operation of a motor including windings and a rotor; placing the motor in a first operational state; driving the motor from the first operational state to a second operational state; and sensing a variation in an electrical waveform induced by driving of the motor to determine a cycle period from which the speed of the motor can be determined.

Abstract: This invention provides a method and apparatus for automatic type discrimination of differently sized disk-shaped information storage media, wherein pulses in a signal generated during the initial rotation and the associated elapsed time are counted and used to detect the size of the disk-shaped information storage medium. The method according to this invention comprises the steps of detecting signals produced from a driving unit for rotating a disk-shaped information storage medium; and identifying the type of the disk-shaped information storage medium according to the size thereof on the basis of comparison of the detected signal with a reference signal. This invention enables to detect the size of the disk-shaped information storage medium in a shorter period time compared to the conventional art because the initial time duration needed to get a desired stable rotation speed, which depends on the size of the disk-shaped information storage medium, is no longer required.

Abstract: A recording apparatus of a master disc of optical discs which can irradiate a recording beam to a preferable position on the master disc even when a vibration occurs in a rotary shaft to hold the master disc or when a rotational fluctuation occurs in a spindle motor. An angle position in the rotating direction of the rotary shaft and a displacement of the rotary shaft in a radial direction of the master disc are detected. Based on the angle position and the displacement, the present deviation at the present angle position from the reference position of the rotary shaft is calculated. Based on the present deviation, the irradiating spot position is adjusted.

Abstract: The frequency rectification filter, in principle, measures an amplitude and phase of a particular frequency and compresses the frequency. Accordingly, if no initial value is present, it is necessary to take a time more than one turning cycle. Consequently, no effect can be seen immediately after the rise of an apparatus, and head positioning takes much time. The object of the present invention is to reduce this time. According to the present invention, a state amount of the frequency rectification filter is stored in memory before unloading the head from the disc, so that at apparatus rise, the spindle rotation angle is matched so as to operate the filter, thus increasing the speed of the rise of the effect of the frequency rectification filter. Thus, the risa of the frequency entire apparatus can be performed rapidly.

Abstract: An optical disc drive which can at least read out data from an optical disc is disclosed. The optical disc drive comprises a rotational drive mechanism for rotating the loaded optical disc at a predetermined rotation speed which is one of multiple rotation speed levels; an optical pick-up for reading out data from the optical disc which is rotated by the rotational drive mechanism; a judgement device for making a judgement as to whether the data has been properly read out from a predetermined portion of the optical disc; and a retry control device for lowering the rotation speed of the optical disc from the predetermined rotation speed when the judgement device has judged that the data has not been properly read out from the portion of the optical disc, and then for retrying to read out the data from the same portion of the optical disc rotating at the lowered rotation speed.

Abstract: A control system controls the spin speed of optical media in an optical disc drive, wherein the optical media comprises a premastered area that cannot be overwritten and a user-writeable area that can be overwritten. The control system stops and starts the spinning of the optical media, and controls the spin speed and the direction of spin. The control system also determines whether the commanded spin speed has been attained within a specified time period, and maintains the commanded spin speed. An event issues when the commanded spin speed was not attained within a specified time period, when a problem is detected while attempting to maintain the commanded spin speed, and when the optical media stops spinning. A laser in the disc drive is turned off when spin is turned off.

Abstract: The invention relates to a method of detecting the amount of rotational vibration generated from the rotation of the disk so that the amount of rotational vibration due to the unbalance of the disk can be correctly detected without the additional circuit using the vibration sensor thereby providing data which can assist a series of reactions to prevent a noise or vibration generated from the device. The method comprises the following steps of: the first step of counting number of a traverse signal in a low rotational velocity of a record medium; the second step of counting number of the traverse signal in a high rotational velocity of the disk after completing the first step; the third step of calculating the difference between the numbers of the traverse signals counted in the first and second steps; and the fourth step of converting the traverse signal number difference calculated in the third step into the amount of rotational vibration.

Abstract: An optical axis angle adjusting device is provided, which can adjust the optical axis angle, which can prevent sound skipping or noise in the image of the optical reproduction device even when the disk has certain surface undulation. In the adjusting device, an adjustment disk 10 is inclined relative to the turn table. Rotation phases of the disk are detected, and incident angle is detected at the respective rotation phases. The optical axis angle is adjusted so that the incident angles at the respective phases are identical with each other. Because the disk is inclined, the incident angle can be detected accurately, and the optical axis adjustment can be achieved accurately.

Abstract: A method of controlling a disk writing operation based on a currently remaining electric power capacity of a battery is disclosed. This method is applicable to a portable device such as an electronic notebook or a disk drive using a battery as a power source. This method detects a remaining electric power capacity of the battery, compares the detected remaining electric power capacity with a reference capacity required for completing a writing operation, and then, if the detected remaining capacity is lower than the reference capacity, stops the current writing operation and conducts a data writing closing operation for properly closing or terminating the current writing operation. As a result, the present invention prevents effective disk damages caused from an abnormal writing termination due to the complete discharge of the battery.

Abstract: A disc reading control apparatus 10 comprises operation information inputting means 12 for inputting information concerning a data getting operation A and a searching operation B in a data reading operation with respect to a disc recording medium; operation ratio determining means 14 for determining the ratio of the searching operation B to the data getting operation A on the basis of the information inputted from the operation information inputting means 12; and rotational speed setting means 16 for setting the rotational speed C of the disc recording medium lower if the foregoing ratio of the searching operation determined by the operation ratio determining means 14 is greater than a predetermined value.

Abstract: A rotation number control device for a disk signal reproduction apparatus that reproduces information using a disk on which the information is recorded along a spiral track, such as an optical disk or a magnetic disk. The rotation number control device includes a drive unit which rotates a disk, a rotation number detection unit which detects the rotation number of the disk, a rotation number control unit which controls the rotation number of the disk rotated by the drive unit, a vibration detection unit which detects vibration due to rotation of the disk, and a rotation number storage unit which, for each disk, stores a rotation number of the disk at a time when maximum vibration in a disk allowable vibration range is produced during rotational acceleration of the disk, as a maximum allowable rotation number. The rotation number of the disk is controlled so as not to exceed the maximum allowable rotation number of the disk which is stored in the rotation number storage unit.

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 storage apparatus has a function of controlling rotation of a recording medium which is divided into a plurality of zones in a radial direction thereof and employing a ZCAV system. The storage apparatus is provided with a setting part for setting a mode to one of a normal mode in which the recording medium is controlled to rotate at a first rotational speed, and a high-speed mode in which the recording medium is controlled to rotated at a plurality of second rotational speeds respectively corresponding to a plurality of areas to which the recording medium is divided in the radial direction thereof.

Abstract: A disk drive is disclosed comprising a bias layer in a magnetoresistive (MR) head actuated over a disk having a plurality of data tracks, each data track comprising a plurality of sectors. A sync mark detector detects a sync mark pattern in a sector, wherein when the sync mark pattern is detected a sync mark detect signal and a polarity signal are generated. The polarity signal indicates when the polarity of the bias layer has deviated from a preferred polarity, wherein the polarity of the bias layer is realigned back toward the preferred polarity.

Abstract: In a seek operation, in which a head is moved to a target track, the detection output of a head-position detection unit is integrated in each track. Each integrated value is a positive or negative value proportional to an offset given to a center value obtained from the maximal value and the minimal value of the detection output. The center value is compensated for by a compensation value obtained by multiplying the integrated value by a coefficient. As a result, the offset is reduced and a highly precise positional detection is allowed.

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: In a lens actuator for use with an optical recording and reproducing apparatus in accordance with a plurality of different multiplied response numeric values to record or reproduce to or from an optical recording medium, the lens actuator actuates an objective lens to control focusing and tracking and includes a fixed magnetic circuit including a magnet as a magnetic flux generating source and a back yoke, a support structure that is elastically displaceable depending on a thrust generated amount; and a movable part including a holder fixing the objective lens and a solenoid coil capable of generating a focusing thrust and a tracking thrust in accordance with current values, respectively. And in the lens actuator, a resonance frequency around a tangential axis is set to be different from spindle rotation frequencies corresponding to the plurality of multiplied response numeric values.

Abstract: An information reproducing method includes the steps o of reading information from an information medium that is rotated, and determining a rotation velocity of the information medium on the basis of a data transfer rate based on a specification of a read request.

Abstract: An optical disc drive for playing back or recording and playing back an optical disc comprises a motor for rotating an optical disc, an optical pick-up having an objective lens which is actuated by servo operation, and a CPU for controlling the motor and the optical pick-up. The CPU is constructed to control the motor and the optical pick-up so that, when the rotation number of the optical disc is to be increased to a first target rotation number, the rotation number of the optical disc is provisionally set to a second target rotation number which is smaller than the first target rotation number, and the servo operation of the optical pick-up is caused to engage until the rotation number of the optical disc reaches the second target rotation number.

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: While a control portion changes the laser power stepwise with a laser power control portion, the optical disk apparatus of the present invention compares a predetermined level with an output by a detector that detects the correlation between a pattern to be recorded on the optical disk and the reproduction signal of the recording pattern detects as the minimum recording power the recording power when the originally smaller of the predetermined level and that output by the detector becomes larger than the other, and sets the optimum recording power to a power obtained by multiplying the detected minimum recording power by a certain factor.

Abstract: This invention discloses an optical servo writer. The optical servo writer includes an optical pickup head for rotationally moving over and writing servo data in an optical flat data-storage medium. The optical servo writer further includes a clock head for providing clock signals to the pickup head and to write clock signals in the clock disk. The optical servo writer further includes a control circuit for controlling The optical pickup head for writing the servo data on The optical flat data-storage medium. The optical servo writer further includes a servo pattern layout circuit for controlling The optical pickup head for writing the servo data on The optical flat data-storage medium with predefined servo patterns. The optical servo writer further includes a derived index control circuit for deriving indices from a fixed index provided on The optical flat data-storage medium.

Abstract: A rotation number control device for a disk signal reproduction apparatus that reproduces information using a disk on which the information is recorded along a spiral track, such as an optical disk or a magnetic disk. The rotation number control device includes a drive unit which rotates a disk, a rotation number detection unit which detects the rotation number of the disk, a rotation number control unit which controls the rotation number of the disk rotated by the drive unit, a vibration detection unit which detects vibration due to rotation of the disk, and a rotation number storage unit which, for each disk, stores a rotation number of the disk at a time when maximum vibration in a disk allowable vibration range is produced during rotational acceleration of the disk, as a maximum allowable rotation number. The rotation number of the disk is controlled so as not to exceed the maximum allowable rotation number of the disk which is stored in the rotation number storage unit.

Abstract: The invention relates to a method and a device for recording an information signal 10 in a phase change layer of a recording medium. A mark is recorded by a sequence 13 of write pulses and previous marks between the marks to be recorded are erased by a sequence of erase pulses 14. De bias power level 191, 192 between the erase pulses is made dependent on the recording speed, thus obtaining low jitter of the recorded marks and at the same time preventing thermal cross write during erase.

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: The present invention relates to a method and an apparatus for controlling the rotation of a turntable, in order to move a disk mounting portion selected among a plurality of disk mounting portions installed on the turntable to a pickup side by a key input signal of a user which includes rotating the turntable by supplying a driving voltage to a turntable driving motor, sensing a rotational velocity of the turntable and the extract output delay time Td of the driving voltage of the motor for stopping the pertinent disk mounting portion at a reproducing position on the basis of the sensed rotation velocity, and cutting off the driving voltage output of the turntable driving motor after confirming the approach of the pertinent disk mounting portion to a reproducing position and confirming the output delay time.

Abstract: There is disclosed an information storage apparatus with a low current consumption in a spindle motor or the like. A spindle motor driver 38 and spindle motor 40 serve as both a driver for driving a disk-like information storage medium in a predetermined direction and a brake for forcibly stopping rotation of the information storage medium, and by appropriately inputting, to the spindle motor driver 38, a spindle-on signal SPDLON for operating the spindle motor driver 38 and spindle motor 40 as the driver and a brake signal BRAKE for operation as the brake, MPU selectively uses a forced stop operation for stopping driving the information storage medium to forcibly stop the information storage medium, and a natural stop operation in which the spindle motor 40 simply stops driving the information storage medium.

Abstract: An apparatus for recording and/or reproducing information on and/or from a magneto-optical disk including an optical head for projecting a laser beam onto a magneto-optical disk and receiving the laser beam reflected by the disk, an up-down block arranged movably between a lower position and an upper position, an up-down motor for moving said up-down block up and down, a turntable for supporting the disk and a spindle motor secured to said up-down block and having a driving shaft coupled with said turntable for rotating the turntable, a position detecting device for detecting a position of said up-down block to derive a position signal when the up-down block is driven into the upper position, a rotation detecting device for detecting a rotation of said optical information record disk to derive a rotation signal when the optical information record disk is rotated at a predetermined revolving speed, and a control device for initiating a focus control for moving said objective lens and turntable relative to each

Abstract: A data reproduction apparatus includes a system controller for monitoring an amount of data in a memory and a linear velocity detected by a linear velocity detecting section, controlling a DC signal output from a DC signal generating section to a disk motor driving section as a drive signal, and controlling interruption and resumption of writing of information to the memory so as to prevent the memory from overflowing. The output DC signal of the DC signal generating section is controlled such that a velocity at which information is written to the memory means is higher than a velocity at which information is read therefrom so as to always store information in the memory, and the linear velocity detected by the linear velocity detecting section becomes close to a preset linear velocity, and the rotation of the disk is controlled by the DC signal. The power consumption required for controlling the rotation of the disk can thus be reduced.

Abstract: A virtual RAM read address generating circuit (41) generates a virtual address on the basis of an output signal of a crystal oscillation circuit (36). A phase comparison circuit (39) which performs phase comparison with a write address, and a spindle control circuit (3) which controls rotation of a disk with reference to outputs of a frequency comparison circuit (38) and the phase comparison circuit (39) are disposed. Therefore, a phase error can be fed back to a spindle motor, thereby preventing linear velocity deviation from occurring in a steady state. By using the thus configured reproducing device, the reproduction quality in the case where a disk wherein recording was performed by the CLV system is reproduced by the variable linear velocity reproduction system is ensured, and both high-speed access and low power consumption are realized.