JPS63160065A - Optical disk device - Google Patents

Abstract

PURPOSE:To reduce erasure rewrite time by applying the propriety of erasure of the information recorded onto a disk, confirmation of classified item, retrieval/ discrimination of track address and range at the reproduction at the 1st rotation of the disk and recording consecutively new information after all information of the corresponding track is erased thereby preventing accidental erasure. CONSTITUTION:A number of revolutions N at normal reproduction of a motor 10 is switched (181) into 3N by a command of a controller 200. A magnetic bias 18 is fed, a laser light 12 is radiated and the information is recorded on a magnetic disk 100 by the Curie point write. Interleaving operation is applied to the information signal whose frequency is trippled through time compression 24 and a frame synchronizing signal is added to a prescribed area. The information signal is inputted to a switching circuit 27, switched by a command of the controller 200, a reproduced output is given through an optical modulation circuit 14 through the 1st revolution, an erasure signal at the 2nd revolution and the recording signal is inputted in the optical modulation circuit at the 3rd revolution and they are compared (43) with the information inputted (41) in advance to discriminate the propriety of erasure and erasure range of the disk. Through the constitution above, the information recording/erasure/rewrite is attained in a short required time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical disc device that uses laser light to record or reproduce information such as audio and video on a disc-shaped disc medium, and in particular, relates to an optical disc device that uses laser light to record or reproduce information such as audio and video on a disc-shaped disc medium. To provide an optical disc device that can perform continuous and simultaneous three rotations of a disc rotated at three times the normal speed and reliably without causing erroneous erasure.

Conventional technology Recently, write-once type (DRAW = WRITE 0NCE)
) Development and research on erasable magneto-optical (MO) type or phase change type optical disks, including optical disks, is progressing rapidly, and various efforts are being made to put them into practical use. In particular, research is being focused on the practical application of erasable/rewritable optical disks that utilize magnetic reversal (magnetism) and phase change of the medium.

When recording information such as audio and video on this type of erasing rewritable optical disc, if there is old information recorded on the recording medium, it is necessary to erase this recorded information before it can be used again. Information cannot be written. Therefore, it is first necessary to erase old information. After that, a laser beam is irradiated from one side of the rotating disk using an optical servo head, and a bias magnetic field corresponding to recording is applied from the other side in the recording direction to reverse the direction of magnetization of the magnetic medium. Information is recorded on the recording trunk of the disc by so-called single-point writing. Furthermore, the written information signal is reproduced by turning off the application of the bias magnetic field, irradiating the disk with a laser beam whose power is weaker than that during recording, and reading the change in the reflected light. Erasing recorded information is performed by applying a bias magnetic field in the opposite direction to that used during recording while irradiating the disk with laser light at approximately the same power as during recording, aligning the direction of magnetization in one direction. be exposed.

By the way, a conventional one-head type optical disk device for recording and reproducing information on this type of erasable/rewritable disk has a configuration in which three modes, erasing, recording, and reproducing, are operated separately for each mode. . In other words, erasing is performed in erase mode, recording is performed in record mode, and signal reproduction is performed separately in playback mode.

The problem that the invention aims to solve is that in the conventional device, when erasing and self-rewriting information, it first erases all the old recorded information in an erase mode, and then erases it in a separate recording mode before writing new information. Writing operations are required, and these modes cannot be performed simultaneously simultaneously. In addition, at that time, the management data such as the address, erasability code, date, classification item, etc. of the information to be erased recorded in the user's area of the disc, etc., is played back and read out in advance, and the information is read out to determine whether it is erasable or not. After searching and confirming the range of track addresses that should or can be erased, it is necessary to specify and input the track addresses, etc. necessary for erasing where the information to be erased is recorded. Therefore, with conventional devices, erasing and rewriting information requires a lot of time, effort, and effort. Further, when erasing data, problems such as accidentally erasing important data that needs to be kept often occur.

The present invention has been made in view of the above points, and it is possible to erase and rewrite information on a recorded disk simultaneously and consecutively during three rotations of the disk that is rotated at 3x speed, and to cause erroneous erasure. The purpose is to make it possible to do so without any problems.

Means for Solving the Problems The present invention provides a light beam that irradiates a laser beam onto an optical disk medium rotated by the drive of a spindle motor to write or read information signals such as audio and video onto a spiral wand or concentric recording track. A head, an optical servo means that performs focus and tracking servo on the laser beam emitted from the optical head, and slider servo on the optical head itself, and a drive signal that corresponds to the recording signal input when recording information on the disk. This relates to an optical disk device equipped with an optical modulation circuit consisting of a laser drive circuit that excites the laser element of the optical head by giving the laser element of the optical head, and when recording information on the disk, the servo circuit of the spindle motor triples the motor rotation speed. A rotation speed switching circuit that provides a switching signal for switching, a time compression circuit that compresses the input information signal to 1/3 in time and increases the frequency by three times according to the disk rotation speed, and a time compression circuit that provides a switching signal for each rotation of the disk. In synchronization with the reference pulse, the reproduction output read by the optical head is output through the optical modulation circuit during the first rotation of the three disk rotations, and the reproduction output read by the optical head is output during the second rotation of the disk during the three rotations.
a control means for controlling signals so that the information erasing signal issued each time and the time-compressed recording signal are switched in this order and input to the optical modulation circuit at the third rotation; data comparison means for generating a signal by comparing comparison information such as an erasability code, address, classification type, etc. stored in advance during signal reproduction with management data regarding recorded information read from an area of the disk; It is provided as a basic component.

Then, during the three rotations of the optical disk rotated when erasing and rewriting information, a configuration is adopted in which reproduction of the management data and erasing and rewriting of information are switched in this order and are controlled to be performed every rotation.

Transferring new data to an optical disc that has already recorded audio, video, etc.
When writing information, the number of rotations of the spindle motor is tripled depending on the type of disk. While the disk rotates three times, first, during the first rotation, management data such as the address of the information to be erased written on the disk, erasability code, classification category, date, etc. is read in the playback mode. The read data is compared with comparison information stored in advance by a data comparing means, and based on the signal, it is confirmed whether erasing is possible or not, and the track address to be erased and its range are searched and confirmed.

Next, at the beginning of the second rotation of the disk, an information erasing signal is input through the optical modulation circuit in synchronization with a reference pulse that is output every rotation of the disk. As a result, all old information recorded on the disk is erased over a predetermined trunk range.

When erasing is completed, the reference pulse is outputted at the beginning of the third rotation of the disk, and in synchronization with this reference pulse, the information signal time-compressed to ⅓ is inputted through the optical modulation circuit.

As a result, a new information signal is recorded in the predetermined track address range erased during the second rotation of the disk.

As described above, in the first rotation of the disk, it is confirmed whether or not recorded information can be erased, and the necessary track addresses and ranges to be erased are searched and confirmed, and in the second rotation, recorded information is confirmed. Erasing and writing of new information to the track addresses erased in the third rotation can be performed sequentially and simultaneously. In addition, the rotation speed of the disk is three times that of the normal playback only mode due to motor control, and on the other hand, the information signal written to the disk is time-compressed to 173 times, so first, playback, erasing, and recording. The time required for each is 1/3 of the time required for executing the conventional reproduction-only mode, etc., and the time required for erasing and rewriting is reduced to at least 1/3 compared to the conventional case. Furthermore, since the time of the recorded information signal is compressed to 1/3 compared to 3 times the number of disk rotations, the recording density and amount of information are approximately the same as in the conventional example.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block circuit diagram showing a specific circuit configuration of an optical disc device according to the present invention.

In this figure, reference numeral 10 denotes a disk drive motor, a so-called spindle motor, whose rotation is controlled by a spindle servo circuit 11, and a disk-shaped disk medium 100 is loaded onto the turntable. Disk medium 1
As the 00, for example, an MO (magneto-optical) type erasable/rewritable optical disk is applied. On the recording surface of an optical disc (hereinafter simply referred to as a disc) 100, recording tracks are formed in a concentric or spiral shape (usually a spiral shape in many cases).

The recording surface of the disk 100 is irradiated with laser light emitted from the semiconductor laser of the optical head 12 in the form of a beam spot. As a result, only information is written to the recording track of the disc 100, or the written information is reproduced or read.

The optical head 12 is operated by a slider servo circuit 131 of an optical servo circuit 13, which is controlled under a system control 200 that controls and manages the operation of each part constituting the apparatus, during linear feeding in the disk radial direction. (traverse servo). The laser beam irradiated from the optical nozzle 12 to the disk 100 is servoed in the focus and tracking directions by tracking/focus servo circuits 132 and 133 that constitute the optical servo circuit 13, and
The pit row of the recording track formed at 0 is correctly tracked and controlled.

A laser oscillation pulse is applied to the laser element of the optical head 12 from an optical modulation circuit 14 consisting of a laser drive circuit or the like. The laser oscillation pulse is a pulse signal in which an information signal input to write on the disk 100 is modulated by the optical modulation circuit 14, and is also a drive signal for driving and exciting a laser element, and in response to this drive signal, it emits light. head 12
Laser light is oscillated from the laser element.

The disc 100 loaded on the turntable receives and detects the reflected light of the light irradiated onto the disc surface by the photosensor 15 disposed close to the disc 100, and detects the difference in the amount of reflected light. The signal is given to the disc discrimination circuit 16.

The disc discrimination circuit 16 discriminates the type of the disc 100 based on the signal from the photosensor 15. That is, it is determined whether the disk 100 is a read-only type, a write-once type (DRAW), or an MO (magneto-optical) disk that is erasable and rewritable. The determination signal is input to system control 200.

The rotation of the spindle motor 10 is controlled by a pulse generator (
PG), and a pulse is taken in every rotation of the disk.

The pulse signal output from the pulse generator 17 every time the disk rotates is a reference clock when each circuit described later operates, and this reference pulse signal is
Each rotation is input to the system control 200. The operation of each circuit is controlled through the system control 200 based on this reference pulse signal.

The spindle servo circuit 11 includes a spindle motor 10
A rotation speed switching circuit 18 for switching the rotation speed is connected. The rotation speed switching circuit 18 determines, for example, whether it is a write-once type or an erasable/rewritable type disk when the 4W signal from the disk discrimination circuit 16 that discriminates the type of the disk 100 is input to the system control 200. If so, a switching signal for switching the rotation speed of the spindle motor 10 is given to the spindle servo circuit 11 in response to a signal from the system control 200. In response to this switching signal, the spindle servo circuit 11 switches and controls the rotational speed of the motor 10 to three times the N rotations when reproducing a normal read-only type disc, that is, to 3N.

As the spindle motor 10, for example, a brushless D
D (direct drive) motors, DC motors, etc. are used. Furthermore, the rotation method of the disk 100 is CL.
The V (constant linear velocity) method is adopted. Therefore, the rotation speed of the motor 10 is controlled by a spindle servo circuit 11 according to the position of the optical head 12 with respect to the disk.

That is, the pulse generator 17 detects the rotational speed of the motor 10 and provides a signal to the spindle servo circuit 11. The spindle servo circuit 11 controls the rotation of the spindle motor 10 using this signal. In this case, the pulse generator 17 is
It works as a sensor that detects the rotation speed of the motor 10.

Next, reference numeral 18 is an auxiliary magnetic field application mechanism.

When recording information on the disk 100, the auxiliary magnetic field applying mechanism 18 applies a magnetic bias (auxiliary magnetic field) in the direction opposite to the direction in which the recording track is already magnetized.

At the same time, when a laser beam is irradiated from the optical head 12 and the temperature is raised above the Curie point (magnetic transformation temperature), the direction of magnetization of the recording layer made of a magnetic material is reversed. As a result, information is recorded by so-called one-point writing. A guide groove (pre-group) is formed in advance on the disk 100, and by tracking the laser beam irradiated from the optical head 12 along this guide groove, the entire recording surface of the disk will be covered as the disk rotates. A uniform signal can be recorded continuously. In this way, a row of pits of the information signal is formed on the spiral or concentric recording track.

When erasing information, the direction of the auxiliary magnetic field applied from the auxiliary magnetic field applying mechanism 18 is reversed to the direction opposite to the recording direction. At the same time, when the laser beam is irradiated and heated, the magnetization direction of the recording track returns to its original direction and the signal is erased.

Therefore, the auxiliary magnetic field applied to the disk 100 is erased and
It is necessary to invert S and N depending on recording. As a method for this reversal, for example, a permanent magnet may be arranged to face the recording surface of the disk 100, and the permanent magnet may be reversed by 180 degrees depending on erasing or recording to switch the polarity. Alternatively, as shown in FIG. 2, a magnetic field may be applied in a fixed direction in advance, and the current switching circuit 19 may switch the direction of the pulse current flowing through the coil 20 depending on erasing or recording. In this case, switching of the pulse current by the current switching circuit 19 is performed alternately by the pulse current from the pulse generator 17 in synchronization with the erasing and recording modes.

When recording information signals such as audio and video on the disc 100, if the input information signal is an analog signal, the low-pass filter 21 cuts out unnecessary signals exceeding the upper limit of the reproduction frequency, and then samples the signal. The signal is sampled and quantized (digitized) in this order in a well-known manner in a circuit 22 and a quantization circuit 23, and is input to a time compression circuit 24. On the other hand, when the input information signal is a digital signal,
It is directly input to the time compression circuit 24.

The time compression circuit 24 reduces the time (width) of the quantized input information signal to 1/3 of the original input T.
It has the role of compressing the frequency to T, that is, 1/3, and increasing the frequency to three times the original frequency when input.

The information signal whose frequency has been tripled by the time compression circuit 24 is then passed through an encoding circuit 25 and an error correction addition circuit 26 to which an error correction code related to the signal waveform is added, and the recording order of pulse codes is changed. Operations such as transposing, rearranging the entire code, and so-called interleaving are added. At the same time, a frame synchronization signal or the like is added to a predetermined area.

Next, the information signal is input to the recording/erasing switching circuit 27. The recording/erasing switching circuit 27 is composed of an analog switch, and receives a switching signal from the system control 200 based on the reference pulse signal output from the pulse generator 17, and as described later, the recording/erasing switching circuit 27 is configured with an analog switch. It is alternately switched between the input side of the information signal (recording signal), that is, the recording side, and the input side of the information erasure signal, which is output from the erasure generation circuit 28 at least once during three rotations of the disk. The alternating switching operation of the switching circuit 27 needs to be synchronized with the respective operations of inputting the recording signal and inputting the erasing signal. In other words, during 3 rotations of the disk, 1
During the reproduction, erasing, and recording modes performed every rotation, it is necessary to reliably switch to the input side of the erase signal when erasing, and to the input side of the recording signal when recording. Therefore, the operation is controlled in this manner using the reference pulse as a synchronizing pulse.

The signal output from the recording/erase switching circuit 27 is sent to the recording amplifier circuit 2.
The signal is input to the recording/reproduction switching circuit 29 via 81. This switching circuit 29 is composed of an analog switch like the switching circuit 27 described above, and is composed of an analog switch.
00's operation control, the information signal is input to the input side when the information is in the information recording mode that occurs during the third rotation of the disk, and to the signal reproducing circuit side during the reproduction mode that occurs during the first rotation of the disk. In the erasing mode performed in the second rotation, as in the recording mode, the input side of the recording signal is
Switching is performed in synchronization with the switching operation of each mode performed in synchronization with the reference pulse.

The recording information signal input to the recording/reproduction switching circuit 29 is
The light is input to an optical modulation circuit 14 consisting of a laser drive circuit, etc., where it is modulated and then applied to the laser element (semiconductor laser) of the optical head 12. The laser element is driven and excited by the signal applied from the optical modulation circuit 14 to oscillate. When recording information, this oscillated laser light is changed into a recording signal to change the intensity of the optical signal. As a result, optically modulated laser light is irradiated from the optical head 12 onto the rotating disk 100, and information signals are transferred in the form of bits to the recording trunk formed on the disk 100 by the trA action with the auxiliary magnetic field applying mechanism 18. are recorded continuously.

On the other hand, when reproducing the signal written on the disc 100, the reproduced signal taken out from the optical helad 12 enters the recording/reproduction switching circuit 29 through the optical modulation circuit 14.
The signal is input to the signal reproducing circuit through this switching circuit 29 which is switched to the reproducing side. The time axis of the reproduction signal input to this signal reproduction circuit is compressed to 1/3 by the above-described time compression during recording, except for reproduction-only discs.

In the signal reproducing circuit, the input reproduced signal is first inputted through a reproducing amplifier circuit 31 to a demodulating circuit 32 and an error correction circuit 33 in this order. The signal is then input to the reproduction signal switching circuit 34.

The reproduction signal switching circuit 34 is switched to either one depending on the type of the disc 100 determined by the disc determining circuit 16. In this case, since the time-compressed signal is recorded in 173 on discs other than read-only discs as described above, the switching circuit 34 is switched and connected to the following time expansion circuit 35. therefore,
The reproduced signal is input to a time expansion circuit 35 through a switching circuit 34.

The time expansion circuit 35 triples (1/3T - T
), and lowers its frequency to 1/3, that is, returns it to the frequency level of the original input signal before time compression.

The reproduced signal, which has been time-expanded by the time expansion circuit 35 and returned to its original frequency, is D/A converted through a D/A conversion circuit 36 and an interpolation filter 37 in a well-known manner, and then smoothed. It is extracted as an analog playback output.

On the other hand, the disk 10 discriminated by the disk discriminating circuit 16
When 0 is a playback-only disc, a switching signal is output from the system control 200 to the playback signal switching circuit 34 in response to the input of that signal.

With this switching signal, the switching circuit 34 is switched from the time expansion circuit 35 side to the other side. Therefore, the reproduced signal output from the error correction circuit 33 is taken out as a reproduced output through the D/A conversion circuit 36 and the interpolation filter 37 without passing through the time expansion circuit 35.

Furthermore, this device includes a comparison information input circuit 41 and a comparison information input circuit 41 for determining whether or not the information can be erased, the range to be erased, etc. when erasing or rewriting information written on the disk. A memory 42 for storing information is provided.

The comparison information is composed of information related to the information recorded on the disc (track address, erasability code, classification type, date, etc.), and is input to the memory 4 through the comparison information input circuit 41.
2 and is stored in advance. The comparison information stored in the memory 42 is read out from the user's bits (area) of the disk 100, etc. (trunk address, erasability code, year, month, date, , classification category), etc., are compared with data related to the information to be deleted.

That is, within the frame of the disc 100, for example, a signal area called a subcode is prepared, and in an empty area called a user's bit (area),
Management data related to the written information (track address, erasability code, recording date, classification item), etc., is recorded. The management data written in this user's bit is read out during signal reproduction during the first rotation of the disk, and is input to the information comparison circuit 43 through the signal reproduction circuit.

The information comparison circuit 43 compares the management data read from the disk 100 and inputted with comparison information stored in advance in the memory 42, and provides the compared signal to the system control 200. As a result, when erasing or rewriting information, it is possible to determine whether the information can be erased or not, and to search and confirm the address and range thereof necessary for erasing, classification items, and the like.

Next, the operation of this device having the above circuit configuration will be explained.

Note that the optical servo operation of the optical head 12, the reversal operation of the magnetic field applied to the disk 100 by the auxiliary magnetic field application mechanism 18, the switching operation of the switching circuits 27 and 29, etc. are performed based on the reference pulse signal from the pulse generator 17. Based on this, the operation is controlled by the system controller 200 in accordance with the rotation of the disk 100, and is performed in good time and synchronization with each other.

When erasing or rewriting information written on the disk 100, the disk 100 is first rotated by the spindle servo of the motor 10 at three times (3N) the rotation speed as in the normal reproduction only mode. At this time, the recording/erase switching circuit 27
The pulse generator 17 is connected to the information signal input side and the erasure generation circuit 28 side, and the recording/reproduction switching circuit 29 is connected to the recording signal input side and the signal reproduction circuit side, respectively, according to preset operating procedures and timings. Switching control is performed every one of the three rotations of the disk in synchronization with the reference pulse from . The erasure@rewriting of information is performed during three rotations of the disk 100, which is rotated three times.

During the three rotations of the disk 100, the optical nozzle 12
The spot of the laser beam irradiated onto the disk 100 from Pulse 1st round, 2nd round, 3rd round...-
The kick pulse at the beginning of each layer is traced on the same recording track A.

First, when erasing/rewriting information, when the track address/range to be erased is entered, for example "from what address to what address," the playback mode is activated during the first of the three revolutions of the disc. and optical head 1
The disk 100 is illuminated by a spot of laser light irradiated from 2.
The management data regarding the above erasure is read from the user's bit. The read management data is sent to the signal reproducing circuit through the optical modulation circuit 4, and is input to the information comparison circuit 43 at its output stage. Here, it is compared with comparison information stored in memory 42, and the compared signal is sent to system control 200.

This determines whether or not the information signal written on the disk 100 can be erased, the erasure range (necessary address and its range), etc.

In the playback operation of the first rotation of the disk, it is determined whether erasing is possible or not, and the necessary address range required for erasure is searched and determined. Next, in the second rotation of the disk, the necessary address range is determined by the erase operation. The entire range will be deleted.

In this erasure operation, an information erasure signal output from the erasure generation circuit 28 is optically modulated through the switching circuit 27 which is switched to the erasing side, the recording amplifier circuit 281, and the switching circuit 29 which is switched to the recording side. circuit 14
is applied to the optical head 12 through this optical modulation circuit 14.
is added to the laser device. With this, disk 1
The old information recorded in 00 is changed in the direction of magnetization of the magnetic medium by heating by the laser beam emitted from the laser element and the bias magnetic field applied from the auxiliary magnetic field application mechanism 18 in the erasing direction. direction, and all necessary erasing ranges are erased.

When erasing is completed, the recording/erasing switching circuit 27 is switched to the recording signal input side in synchronization with the reference pulse signal from the pulse generator 17. At this time, the recording/playback switching circuit 29
is maintained switched to the recording side. Furthermore, the polarity of the auxiliary magnetic field applying mechanism 18 is reversed with respect to the medium surface of the disk compared to when erasing.

Next, the disk 100 rotates for the third time, and the beam spot of the laser beam enters the third trace on the same recording trunk. During this third round, the information signal inputted after being time-compressed as described above is applied from the recording side of the recording/reproduction switching circuit 29 to the laser element of the optical head 12 through the optical modulation circuit 14. Then, due to the laser beam emitted from the optical head 12 and the bias magnetic field in the recording direction applied by the auxiliary magnetic field applying mechanism 18, the input new information signal is continuously formed in the form of pits on the recording track of the disk 100. written in.

Thus, in the second revolution of the disk, new information is written in the necessary address range or area where the information was erased following the erasure.

On the other hand, when playing back signals from playback-only discs, etc., recording/
The reproduction switching circuit 29 is switched to the signal reproduction side. At this time, the recording/erasing switching circuit 27 is kept switched to the recording signal input side. Further, the auxiliary magnetic field applying mechanism 18 is switched off, and no bias magnetic field is applied to the disk 100. Then, the rotation of the disc is switched to N rotations in the normal playback only mode.

As described above, the erasing and rewriting of information signals on the recording tracks of the disk 100 is carried out during three revolutions of the disk 100, during which the laser beam irradiated to the disk 100 makes three revolutions on the same recording track, and the laser beam is cut in between. Instead, they are performed sequentially and approximately simultaneously in chronological order. According to this, the disk 100 rotates at three times the rotation speed as in the normal playback only mode, and the time width of the information signal written in response to this rotation is 1
73, and the erasing and recording operations are completed during three revolutions of the disk, which corresponds to one revolution of a conventional read-only disc, so the time required for recording is reduced to 1/3, and the time required for erasing and rewriting is , only the time required to execute one mode of erasing or recording using the conventional recording method is reduced to about 1/3 compared to the conventional method. Also, since the time compressed to 1/3 is recorded on the disk 100 which rotates at 3 times the number of revolutions, the actual recording time is, for example, 1/60 seconds of information becomes 1/180 seconds. However, since the disk rotation speed is three times as large, the written information itself has an amount of information (recording density) of 1/60 of the original.

As described above, during the three rotations of the disk, which is rotated at three times the normal speed, playback, erasure, and recording are repeated in this order every rotation, and new information is sequentially written to the inner or outer circumference of the disk. and it will be executed.

Note that a clock generator may be provided separately, and its clock pulses may be used as synchronizing pulses for operating each circuit. Further, although a clock pulse is usually folded into a predetermined area on an optical disc, this may be used as the reference pulse.

As described in detail, according to the present invention, when erasing or rewriting information on a recorded disc, it is possible to confirm whether or not the recorded information written on the disc can be deleted, confirm the classification category, etc., and erase the information. The search and determination of the track address range necessary for
Since new information is recorded continuously and simultaneously, erroneous deletion of important information that needs to be kept is prevented. In addition, since erasing and rewriting can be performed while searching and confirming the track address to be erased, the classification item, etc., it becomes possible to record information by random access and rewrite the erasure group for each classification item. Furthermore, the time required for erasing and rewriting is 1/3 of the conventional time, and since they can be performed simultaneously and consecutively, the time required for erasing and rewriting is at least 1/3 of the conventional time, which is a significant reduction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a specific example of the circuit configuration of an optical disk device according to the present invention, FIG. 2 is a circuit diagram showing an example of the auxiliary magnetic field applying mechanism, and FIGS. ), (
D) is an explanatory diagram schematically showing the information erasing/rewriting operation by the device according to the present invention. 10...Spindle motor, 17...Pulse generation W, 100...Disk, 15...Photo sensor, 16...Disc discrimination circuit , 11... Spindle servo circuit, 18...
... Rotation speed switching circuit, 14 ... Light modulation circuit, 24 ... Time compression circuit, 28 ... Erasure generation circuit, 27 ... Recording/erase Switching circuit, 12...
・Optical head, 29... Recording/playback switching circuit, 35...
- Time expansion circuit, 41... Comparison information input circuit, 42... Memory, 43... Information comparison circuit. Patent Applicant NEC Home Electronics Figure 2 F No. 31”1 (D) Regeneration (B) Regeneration

Claims (1)

[Claims] (1) An optical head that irradiates a laser beam onto an optical disk medium rotated by the drive of a spindle motor to write or read information such as audio and video onto a spiral or concentric recording track, and a laser beam irradiated from this optical head. an optical servo means for focus and tracking servo of the laser beam and slider servo for the optical head itself; A rotation speed switching circuit that provides a switching signal for switching the motor rotation speed by three times to a servo circuit that performs spindle servo control of the motor when recording information on the disk, in an apparatus comprising an optical modulation circuit consisting of a laser drive circuit or the like that causes oscillation. and a time compression circuit that compresses the time of the input information recording signal to 1/3 and increases the frequency by three times according to the number of disk rotations, and a time compression circuit that is synchronized with the reference pulse that is output every time the disk rotates. A reproduction output read by the optical head is outputted through the optical modulation circuit during the first revolution of the three rotations of the disk, and an information erasing signal is outputted at least once during the three rotations of the disk during the second rotation. A control means for controlling the signals so that the time-compressed recording signals are switched in this order and input to the optical modulation circuit during the first rotation of the disk, and a control means for erasing which is stored in advance when reproducing the signal for the first rotation of the disk. Comparing information such as codes, addresses, classification items, etc. and management data regarding recorded information read from the area of the disk, and outputting a signal by comparing the comparison information, the data comparing means outputting a signal, and during three revolutions of the rotating disk. The optical disc device is controlled so that the reproduction of the management data and the erasing and rewriting of information are performed in this order every rotation.