JP3361208B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Disc recorder that records and reproduces information on media
Things. [0002] 2. Description of the Related Art Information recording for recording and reproducing digital signals
Carriers and their devices are aimed at miniaturization and extension of recording / reproduction time.
Pointing out, a new system is being developed. example
For example, a disk with a diameter of 64 mm stored in a cartridge
(Hereinafter referred to as mini-disc) to reduce the size,
Compression of audio data enables recording on a par with a compact disc
Obtain playback time and insert semiconductor memory as data buffer
Technology to improve vibration resistance during playback.
There is a recording / reproducing device (hereinafter, referred to as a disk recorder). Recently, research on recording films of optical disk media has progressed.
Only recordable optical discs have been developed and
A device that records the same disk format as a CD is available.
Has been used. These recordable optical disks include:
Recording with heat generated by irradiating laser light
By deforming the film or burning out the recording film
By forming a recording bit, it can be recorded only once and erased
Direct Read Afte
rWrite: DRAW) What is called an optical disk
In the same way, laser light is used as a light source,
External magnetic field from the opposite position to the light source,
Information is recorded by changing the direction of the perpendicular magnetism of the recording film.
Erasable type (Erasabl
e-DRAW, magneto-optical type)
There is no. [0004] Among them, those already put into practical use
Computer external storage devices
You. When erasing these magneto-optical disks, the recording film
Apply a magnetic field opposite to that during recording while heating with
Erase operation is performed. On the other hand, for playback of magneto-optical disks
Is called the Kerr effect to read the direction of magnetization.
The aero-optic phenomenon is used. Vertically polarized laser light
When incident on the magnetized film, the deflection surface of the reflected light
Thus, a slight rotation to the left or right. Check this rotation
The information is reproduced by being converted into a change in light amount by photons. However, a magneto-optical disk recording apparatus as described above
When recording and erasing a magneto-optical disk,
N from the position opposite to the laser beam across the optical disc
Generates a magnetic field of the pole or the S pole,
When forming a bit, use a laser
Power to high power, and when bits are not formed, playback power
Outputs low power in the same way as
There is a known optical modulation method that performs recording and erasing by adjusting
The magnetic field at this time functions auxiliary during recording.
In this case, the already recorded portion is overwritten.
The thing was impossible. On the other hand, although the operation principle is the same,
Emit laser light with constant power across magnetic disk
And reverse the N and S poles of the magnetic field, contrary to the light modulation method.
Mini disk system for recording by
You. This method modulates the magnetic field and records it,
This is a magnetic field modulation recording method that enables overwrite. This
In the method of the above, when further recording the part already recorded
Deletes the part to be newly recorded once and then records
Overlap recording without wasting time
Is possible. A disk of the magneto-optical modulation recording system as described above.
In recent years, systems that use audio compression / decompression technologies
Therefore, as in the case of the conventional CD, the reproduction level is 2 channels.
Sampling frequency of 44.1 kHz, 16 bits
A magneto-optical disk having a high resolution has been proposed. This
In the method, the amount of information to be recorded and reproduced is reduced to one-fifth.
To a disc such as an optical disc or a magneto-optical disc.
No. is recorded, and the information read during playback is expanded to
Similar audio performance. [0008] The main feature of this method is the disk diameter.
Is 64 mm and the track pitch is 1.6 μm
Record and play back up to 74 minutes of audio data
Is 1.2 to 1.4 m / sec. Also, audio
The performance of the E signal is that the number of channels is stereo 2 channels,
Frequency band 5-20kHz, dynamic range 105
The recording method in dB is the magnetic field modulation method as described above. Change
The signal format is a sampling frequency of 44.1 kHz and variable.
The tone system is EFM (Eight to Fo) similar to CD.
error modulation) and error correction
The method is also ACIRC (Adaptive Cross I
interleave Read-Solomon Co
de). The audio compression method is a high-performance encoding method.
ATRAC (Adaptive Transform)
Acoustic Coding)
This method uses analog-to-digital converted audio
Data is divided in a time frame of a maximum of 11.6 m / sec.
CT (Modified Discrete Cosi)
neTransform: modified discrete cosine transform
Into multiple frequency bands by MDCT and frequency axis by MDCT
After conversion, thinning is performed using human auditory characteristics,
The data is compressed to about one fifth of the data amount. Therefore, the magneto-optical
The recording density on the disc is the same
The disc diameter required for recording and playback between
The diameter can be as small as 64 mm. The major feature of such a disk system is
Let's consider. When playing a CD, the CD must be 1.4M
Digital-to-analog converter without interruption
(DAC). Therefore, CD
Playback signal must be read out in real time
Absent. On the other hand, optical carrier recording using compression / decompression technology
In the case of a device, the amount of information to be recorded and reproduced is reduced to about 1/5
To compress signals read at 1.4 Mbit / s
Since it is a signal, it takes 0.3M bit to decode it.
G / s is sufficient. Therefore, the signal of the disc is interrupted.
It is sufficient to read out intermittently. A storage circuit such as a buffer memory has a disk
If the signal read from the memory is stored, it can be stored in this memory circuit.
It is possible to reproduce only the audio signal obtained. Therefore,
Vibration is applied to the disk system,
The trace is out of its original position and
Until burr, if a CD player, skip the sound
But in the case of a mini disk recorder
The stored memory circuit prevents the sound from being interrupted. This note
While reading from the memory and playing back continuously,
The cup returns to the original position where the trace on the optical carrier has come off.
If you continue reading the signal, no sound skipping will occur.
Will be. Use of the above-mentioned storage circuit and compression / expansion technology
Gives rise to another major feature. One CD
Songs, or tracks, must be consecutive
It is recorded in a lump in a. However, the mini disk system
A random area on the disc.
Even if the track is divided and recorded as track recording data, one track (track
) Can be played back. This is from disk
Reads out signals at a transfer rate of 1.4 Mbit / s
However, the transfer rate required to demodulate the compressed signal is 0.
Since it is 3 Mbits / sec, there is an idle time
You. Using this time, once from the disk
After reading out the signal and storing it in the storage circuit,
Upper distant area (one track is divided into several distant blocks
Next block of the track consisting of the record data
Move the optical pickup until the recording data
Read the signal from the disk and before the memory circuit becomes empty
If stored in a memory circuit,
And can output. Thus, the same music (track) is recorded on the disk
A continuous audio signal was recorded in the remote area above
Can be reproduced without interruption. One tiger
The block is composed of multiple small block recording data (continuous on the disc).
The small block recording data consisting of the
There are a plurality of them dispersed. Hereinafter, the small block recording data
Information indicating that the data consists of
(Song composition information) is a predetermined
Registered in the location. So, for example, change the song number
When editing or splitting one song into two
This disk system uses table of contents information when
By rewriting the composition information (connection information) of the music in the
You can simply change it. As described above, the mini disk system is called
In the case of a magneto-optical disk recording / reproducing device, etc.
One track is composed of a plurality of parts.
The continuous information of these songs is
It exists for each rack, and the information is M
D is recorded and registered in a predetermined area. The table of contents information is recorded below.
The predetermined area to be used is UTOC (User's Tabl).
e of Contents) area. This UT
In the OC area, in addition to the configuration information of each track,
Year and date information recorded on the disc, the disc name and
Additional information such as the name of a lock can also be recorded and registered. [0016] SUMMARY OF THE INVENTION
In a storage system, etc., data stored in a storage circuit
If there are enough addresses, a certain address may be read due to disturbance, etc.
If an error occurs (address error)
Even in this case, one track jump is performed on the inner circumference,
Can be read again. Only
However, MD has a smaller radius than CD, so it rotates faster and inner circumference
Trace time of one track is short from
I made one track jump on the inner circumference
Sometimes a focus error or tracking error due to disturbance
Focus servo and tracking
The ad was trying to read again before the
When the optical pickup reaches the position of the
It becomes an address error and repeats the same thing,
When it reaches the limit of the number of repetitive searches, its address
Becomes an unreadable address, and the sound of that address
Unable to output voice data, skipping or interruption of sound
Had become the cause. An object of the present invention is to provide a method for controlling an
Optical pickup to the inner circumference to read the address again
Moves, and errors occur in the tracking servo and focus servo.
-Occurred and the address to be read again cannot be read again.
The number of occurrences of address errors.
The number of track jumps increases each time the
The tracking servo and focus servo work properly.
Read the address by extending the time until it works
Disk recorder with algorithm to ensure things
It is to provide. The optical disk device according to claim 1 of the present invention
According to the optical pick-up for reading signals recorded on an optical disc,
And the address from the output signal of the optical pickup.
A signal processing unit that demodulates optical information;
focusServo for servo control of tracking and tracking
Reads the control unit and the address information where the address error occurred.
Detects whether or not the address information has been obtained and the address information cannot be read
In the case, the optical pickup is controlled by controlling the servo control unit.
Control unit to make track jump to the inner circumference side of the optical disk
And the address information in which the control unit has caused an address error.
Storage means for storing the number of times the Said
The control unit controls the servo unit and stores the data in the storage unit.
The optical pickups as many times as
Make the track jump to the inner side of the trackCharacterized by
I have. [0019] [0020] [0021] [0022] According to the present invention, data stored in a storage circuit is stored.
If there is enough address error, a certain address error
Even if the
When making a track jump in the radial direction, the MD
In the same case, because the radius is smaller than CD, rotation is faster and inner circumference
The trace time of one track becomes shorter from the
And jumped one track on the inner circumference
Focus error or tracking error
Focus servo and tracking
The ad was trying to read again before the
The optical pickup reaches the location of the
It becomes a dress error and repeats the same
When the limit of reach is reached, the address cannot be read
Address, and the audio data of that address
Output cannot be performed, causing skipping or interruptions in the sound.
To prevent address errors from occurring.
Because the amount of movement of the optical pickup increases accordingly,
Address can be read in normal condition,
Disruption can be prevented. [0023] DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a mini-disc recorder according to the present invention
An example will be described with reference to FIGS. FIG. 1 shows one embodiment of the present invention.
FIG. 2A is a block diagram of hardware showing an embodiment;
(B) and (c) are optical picks used in one embodiment of the present invention.
FIG. 3 is a diagram showing an up-train pattern, and FIG.
It is. One embodiment of the present invention relates to a disc recorder.
And 1 indicates a mini-disc (MD), and MD1 is illustrated
The cartridge can be freely rotated in the cartridge without using the cartridge.
Loading the ridge into the device allows mini disk
Brought on the coder table, the cartridge
MD1 is fixed at the center on the turntable in
The pindle motor 6 is rotatable. The information recording surface of the MD1 has a pit area and a glue.
-The pit area is divided into inner area switches 7
Is controlled by the optical pickup.
-With a micro computer (hereinafter "microcomputer") 21
By detecting, the innermost position of the specified MD1 (start position
Position) can be recognized. Light pick under MD1
Up 2 is arranged, and the recording head of the magnetic head is on the upper side
18 and laser light from the optical pickup 2 is M
It is slidable by the slide motor 5 in the radial direction of D1.
Is done. The recording head 18 has an NS pole corresponding to the recording signal.
This is a magnetic field generating unit for applying the magnetic field of MD1 to MD1. The servo circuit 4 controls the speed of the spindle motor 6.
Handle control, slide control of the slide motor 5,
Focus control and tracking control of light-up 2, light
Performs laser control of the semiconductor laser in the pickup 2
The spindle motor 6 is a spindle motor in the servo circuit 4.
CLV (Constant Lin)
(ear velocity) is controlled and the required number of revolutions
Given. The slide motor 5 is provided in the servo circuit 4
The optical pickup 2 is set to M by the slide motor control circuit.
Controls the sliding operation in the radial direction of D1.
The pickup 2 is also a focus control circuit in the servo circuit 4.
Path, tracking control circuit and laser control circuit.
Focus, tracking and semiconductor laser
/ Off control. First, a reproduction system will be described. MD1 record
The information is read by the optical pickup 2 and the RF amplifier
3 through the address decoder 8 and the EFM (Eight
tto Fourteen Modulation) /
ACIRC (Adaptive Cross Inte
Rieave Read-Solomon Code)
It is added to the decoder 9. The address decoder 8 uses M
Insert the guide groove (pre-groove) preformed in D1
For a CLV control sine wave signal that is meandering by a small amount
The superposed address information is detected and demodulated. This output
In the EFM / ACIRC decoder 9, EFM and ACIR
C demodulation, and the output is
It is input to the control circuit 10. The semiconductor memory control circuit 10 is
From the EFM / ACIRC decoder 9 entered for raw
Data is stored in a buffer memory such as the semiconductor memory 15.
Audio decompression to demodulate compressed data
For sending the data to the DA (ATRAC demodulation circuit) 11
Has a function. In the audio decompression decoder 11, the compressed
The demodulated data is expanded and demodulated, and the demodulated data is converted to a D / A converter.
The data is sent to the converter 12 and the voice output is output. Next, the recording signal path will be described. Audio
The recording input signal is input, and the A / D converter 13
It is converted to digital data. Digital data is voice pressure
The compression encoder (ATRAC modulation circuit) 14 outputs the above-mentioned voltage.
Converts to compressed data and controls semiconductor memory for vibration proof
Via the circuit 10 to the semiconductor memory 15 which is a storage circuit
Record and store the compressed data. Case for semiconductor memory 15
When the delivered amount reaches a predetermined amount, record data is recorded on MD1.
I do. That is, the compressed data stored in the semiconductor memory 15
Is read by the vibration-proof semiconductor memory control circuit 10.
And outputs it to the EFM / ACIRC encoder 16. In the EFM / ACIRC encoder 16,
Performs EFM and ACIRC modulation and outputs the output to the head drive.
Output to the driving circuit 17, and the head driving circuit 17
A recording head that generates magnetic fields of N and S poles corresponding to the FM signal
A magnetic field is applied to the MD 1 through the node 18. On the other hand, in MD1
From the optical pickup 2 located on the opposite side,
Output from the servo circuit 4 in response to a command from the
Recording laser power (high power) is irradiated to MD1
You. The magnetic field from the recording head 18 across the MD1 and the light
Recording signal is recorded on MD1 by heat from backup 2
It is. On the other hand, in order to move the optical pickup 2,
The slide control signal from the microcomputer 21 is transmitted to the servo circuit 4
Is applied to the slide motor 5 through the optical pickup 2
Make the move. The microcomputer 21 controls recording, reproducing, and optical
All controls such as search operation of the pickup 2
Signal and detection signal such as address information of MD1
To the servo circuit 4 and the EFM / ACIRC encoder 1.
6. Each part of the semiconductor memory control circuit 10 for vibration proof
And control (management) data is transmitted and received through the bus.
It is. A key 20 is an input device of the microcomputer 21 for various types.
An operation unit that has key blocks for command signals, numeric keys, etc.
Display 19 displays various data from microcomputer 21
Display of table of contents information such as music titles on a display device such as a liquid crystal display
can do. Next, FIG. 3 shows an embodiment of the present invention.
An address error occurs based on the flowchart.
When they are born, they are shown in (a), (b) and (c) shown in FIG.
Address again by one track jump to the inner circumference
When reading a track, focus servo or track
Operation until the servo is determined to function properly.
Even if an address error occurs again because of the delay,
Jump the optical pickup according to the number of occurrences of the rest error.
By increasing the number of tracks to be
Explain that reading a dress is sure. The MD1 is mounted on the mini disk recorder.
Then (S1), TOC (Table Of C) of MD1
content / UTOC information and write it to MD1
The table of contents of the recorded music is displayed (S2). Operate key 20
Then, the number of the music to be reproduced is designated (S3). Microcomputer
The servo circuit 4 is actuated by the command of No. 21 and optical pick-up is performed.
Activate (turn ON) the focus servo of step 2
Drive data 5 to perform tracking servo and spin
Operate the dollar motor 6 and operate the spindle servo (ON)
Then, the rotation of the MD1 is controlled to a predetermined rotation (S4). The optical pickup 2 is slid and moved.
Rack jump drive, before the start address of the specified song
Search for the address (S5), and read the address.
It is started (S6). To read a specified address,
Starts a dress search and detects whether the address is the specified address.
(S7) When a predetermined address is detected, the address is
Initialize the count value that counts the number of times an error has occurred
(Clear) (S8), the last address of the song is detected
Until this is done (S10), the data of the music at the predetermined address is
The storage in the semiconductor memory 15 is started in the address order (S
9) Check if audio output has started
(S11) If the audio output has not been started, the semiconductor
Whether a predetermined amount of data is stored in the memory 15
It is detected (S12), and data of a predetermined amount or more is stored.
Then, the sound output is started, and the data stored in the semiconductor memory 15 is stored.
The data is expanded on the time axis via the audio expansion decoder 11 and D
Is converted into an analog signal by the A / A converter 12 and output.
(S13). The amount stored in the semiconductor memory 15 is a predetermined amount
If it is not memorized, it will be
Then, the next address is searched (S17).
The process returns to the address reading (address reading) S6. S11
If audio output has already started at
Immediately read the next address to reduce sound interruptions.
Command S17 and return to address read S6. Final address
In S10 when the music is detected and immediately in S3, the next song is already
Or the designation from key 20
Wait until the song data stored in the semiconductor memory 15 ends.
Everything is read out. Although not shown,
The specification is not limited to only one song, it is specified and specified in order of several songs at once
When the music has been reproduced to the end, the process waits in S3. Next, as shown in FIG.
The compressed data is read along the track
While taking, a disturbance occurs at address A,
Is not readable (S1)
4) At this time, if the number n of address error occurrences is one,
The number of times is counted (count up) (S15). Ma
The icon 21 indicates that the data output from the semiconductor memory 15 is
Predetermined count value n to prevent non-continuation
Is detected (S16), and a predetermined X
When the second time is reached, read the next address.
(S17), returning to the address read (S6). If no address error occurs in S14,
When it is detected that the address has not been reached
Returns to the address read of S6 and reads the predetermined address.
Continue taking. When n does not reach X in S16
Is used to read address A again, as shown in FIG.
And one point from point d on the track to the inner track
Make a track jump and move to point a on the track
(S18). Then, as shown in FIG.
After tracing from point a to point b above, address A
Is reached, but when one jump is executed, the focus
Error occurs in the servo and tracking servo,
Optical pickup while tracing from point a to point b above
If the operation of Top 2 cannot be stabilized normally,
When address A is reached, it is necessary to read address A again.
It becomes impossible (S14). At this time, a count of the number of address error occurrences is made.
The default value is incremented by one and set to twice (S15). Address error
Until the number of occurrences of-reaches a predetermined value, 1
When this track jump is performed, the address A
This example increases the possibility that the
In the case, the number of occurrences of address errors
Increase the number of tracks that jump
An address search from the dress lead 6 is performed. This embodiment
In this case, the same number of tracks as the number of address error occurrences
Track jumps in the inner circumferential direction
I do. Therefore, in the second address search,
As shown in FIG. 2 (b), from the point d on the track,
To make two track jumps on the track
Move to point a '(S18). One track to the inner circumference
A on the track shown in FIG.
Two traces to the inner circumference than the trace time from point to point b
Track shown in FIG. 2B when rack jump is performed
Trace time from point a 'to point b is longer
Therefore, even if an error occurs during a track jump,
− Normal operation and stable state of cas servo and tracking servo
By the time the time becomes longer and reaches address A,
Higher probability that address can be read more stably than last time
Become. In the present embodiment, it is necessary for the stability from point a 'to point b.
Address A cannot be read again even after giving a certain time
At that time, the number of occurrences of address errors is counted.
The count value is set to three (S15). As described above, the number of occurrences of address errors and
Make the number of tracks the same, and add three tracks to the inner track.
Make a rack jump. As shown in FIG.
Three tracks from point d on the rack to the inner track
Jump and move to a '' point on the track
(S18). When you make two track jumps to the inner circumference
From the point a 'to the point b on the track shown in FIG.
Three track jumps to the inner circumference rather than the trace time
From the point a '' on the track shown in FIG.
Since the trace time to point b is longer, jump
Sometimes error in focus servo or tracking servo
Focus and tracking work properly
And the time to wait until it reaches address A
At this point, there is a high possibility that addresses can be read stably.
In this embodiment, the address A is read at this time.
Is normally completed. At this time,
The count value of the number of occurrences is set to an initial value (S8). Of the song
Steps S6 to S18 are executed up to the last address. As described above, the mini disc drive according to the present embodiment is
The coder has a cluster number and a sector number, and
Recording and playback of compressed audio data
Focus control means in a mini-disc recorder
Tracking control means, address reading means,
Means for storing the number of occurrences of address errors;
It is equipped with a jumping means, and after an address error occurs,
Track jump to inner circumference to read the address again
Tracking servo and / or focus sensor
An address where a read error occurred due to a robot error
The number of occurrences of address errors even when
The number of tracks to jump according to
Normal operation of tracking servo and focus servo
By extending the predetermined time interval until the condition stabilizes,
It is a mini disk that rotates at high speed and has a small external shape.
Also, it is possible to reliably read the address. In the above embodiment, the reproducing operation is explained.
As mentioned above, the track to be recorded
Address can be searched. [0044] After an address error has occurred, the address is re-entered.
When you make a track jump to the inner circumference to read the track,
Error in focus control or tracking control due to disturbance
The number of address read errors even if
The width of the track jump is increased accordingly,
The operation of the pickup will be restarted until it is stabilized in the normal operation state.
The address you were trying to read
Repeat the operation of dress error.
Eventually it becomes impossible to read the specified address
To prevent skipping and interruptions caused by sound
Can do things.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of hardware showing an embodiment of a disk recorder according to the present invention. FIGS. 2A, 2B, and 2C are diagrams showing trace patterns of an optical pickup used in an embodiment of the present invention, wherein FIGS. FIG. 3 is a flowchart showing one embodiment of a disc recorder according to the present invention. [Description of Signs] 1 Mini disk 2 Optical pickup 3 RF amplifier 4 Servo circuit 5 Slide motor 6 Spindle motor 7 Inner circumference switch 8 Address decoder 9 EFM / ACIRC decoder 10 Semiconductor memory control circuit 11 Audio compression decoder 12 D / A converter 13 A / D converter 14 Audio compression encoder 15 Semiconductor memory 16 EFM / ACIRC encoder 17 Head drive circuit 18 Recording head 19 Display 20 Key 21 System control microcomputer

Claims (1)

(57) Claims: 1. An optical pickup for reading a signal recorded on an optical disk; a signal processing unit for demodulating address information from an output signal of the optical pickup; and a focus and tracking of the optical pickup. No
Servo control unit that performs servo control and whether or not the address information in which the address error occurred was read
And if the address information cannot be read, the
A control section for controlling a servo control section to cause the optical pickup to perform a track jump to the inner peripheral side of the optical disc; and the control section reads address information in which an address error has occurred.
Storage means for storing the number of times not found, the control unit controls the servo means, the storage unit
The same number of optical pickups are stored in the optical
An optical disk device characterized in that a track jump is made to an inner peripheral side of a disk.