JP3064707B2 - Disk recording and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent recording / reproducing disk recording / reproducing apparatus capable of completely and quickly erasing invalid data on a disk.

[0002]

2. Description of the Related Art It has been a long time since a compact disc (CD) was developed as a medium that surpasses an analog record, and several recording media have been developed in the meantime. A mini-disc (MD), which is expected to have the portability of a compact cassette and the operability and sound quality of a CD, is one of them, and is attracting attention as an audio recording medium in the future.
The MD adopts a new audio compression method while following the PCM method similar to that of a CD, so that the same sound quality as a CD can be realized with an information amount of about 1/5. For this reason, even a disk having a diameter approximately half that of a CD can achieve a reproduction time comparable to that of a CD.

[0003] There are two types of MDs, and a read-only MD that can only play back uses the same optical disk as a CD. On the other hand, a recording / reproducing MD that can perform not only reproduction but also recording uses a magneto-optical disk. An MD player capable of supporting such two types of MDs is equipped with not only an optical head for recording and reproduction but also a magnetic head for recording. An MD player capable of recording and reproducing MD has a recording mode for writing recording data to a disk and a reproduction mode for reading reproduction data from the disk, and the user selects one of these modes.

By the way, to erase audio data once recorded on a recording medium, (1) record a new audio signal, (2) record a signal that becomes analog or digitally silent, (3) There is a method of rewriting information in a table of contents (TOC) attached to a recording area to invalidate data recorded in a corresponding recording area.

[0005]

However, since the above-mentioned methods (1) and (2) basically operate in the recording mode, the erasing time is the same as the recording time, and high-speed erasing cannot be realized. . In order to improve this point, for example, a means such as a bulk eraser used for erasing data recorded on a magnetic tape at a high speed can be considered.
A magnetic head or the like that generates a strong magnetic field required for erasing recorded data on a magneto-optical disk such as D is expensive and is not suitable for mounting on an MD player or the like.

[0006] On the other hand, even if the TOC is edited by the method (3), the recorded data is apparently erased, and unless the new data is overwritten in the corresponding recording area, the data is physically deleted. It remains on the disk. Normal players cannot play back data that has been invalidated by TOC. However, it is conceivable to play that part erroneously or intentionally due to failure, recording medium trouble, equipment modification, etc. It is not preferable from the viewpoint of the above. The present invention improves on the above points,
It is an object of a disk recording / reproducing apparatus for intermittently recording / reproducing data so that recorded data on a disk can be physically completely erased and at a higher speed than at the time of recording.

[0007]

A first disk recording / reproducing apparatus according to the present invention uses a writing means to write data
Recording data intermittently with a waiting period due to compression
A recording mode for writing to the disk, a read mode, a playback mode for intermittently reading playback data from the disk with a waiting time due to data decompression, and a recording data on the disk using the writing means , And an erasing mode in which erasing is performed continuously without interposing a standby time .

A second disk recording / reproducing apparatus according to the present invention uses a magnetic recording head while irradiating a predetermined light from an optical head to a magneto-optical disk to wait for data compression.
The machine time is interposed intermittently recorded data the magneto-optical de
A recording mode for writing to disk, in the optical head, de
A read mode in which read data is intermittently read from the magneto-optical disk with a standby time caused by data expansion, and a write mode of the write magnetic head while irradiating the optical head with light that is substantially the same as or stronger than the write mode. An erasing mode in which the recording signal is turned off or the recording data on the magneto-optical disk is driven by an erasing signal to continuously erase the recording data on the magneto-optical disk without any intervening standby period. And

[0009]

When erasing invalid data on a disk in a disk recording / reproducing apparatus that performs intermittent recording / reproduction, the present invention does not use a normal intermittent recording mode but performs a continuous erasing operation. A new erasing mode to be performed is set, thereby enabling erasing at a higher speed than at the time of recording. In addition, in this erasing mode, not only the TOC is edited but also the erasing operation is actually performed on the recording area, so that invalid data can be physically completely erased from the disk.

When a magneto-optical disk is used as the disk, it is necessary to perform erasure magneto-optically. In this case, when light that is substantially the same as or stronger than that in the recording mode is applied to the disk from the optical head, the temperature at that portion rises above the Curie point, and the recorded data is lost, and physical erasure is performed. At this time, a desired form of erasing operation is performed by turning off the recording signal of the recording magnetic head or by operating to record a predetermined erasing signal.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a main part showing a basic configuration of the present invention. In this figure, 1 is a disk as a recording medium, 3 is a recording / reproducing head used in a recording / reproducing mode, 14 is a recording head used in a recording mode,
In the erase mode, the recording / reproducing head 3 and the recording head 14 are used as in the recording mode. This disc recording and playback device
It has an intermittent recording mode, an intermittent reproducing mode, and a continuous erasing mode. The intermittent recording mode is instructed by the recording instruction key 18A, and the continuous erasing mode is instructed by the erasing instruction key 18B. Is).

Control section 16A, intermittent / continuous recording selection section 16
B, a recording / erasing signal selecting section 16C is each function of the system controller of the disc recording / reproducing apparatus, and the control section 16A controls the whole, and the intermittent / continuous recording selecting section 16B
Selects whether the recording operation is performed intermittently or continuously. The recording / erasing signal selector 16C selects whether the signal to be recorded on the disk 1 is a normal recording signal or an erasing signal for erasing. The recording signal is generated by the recording signal generation unit 2
1 and the erase signal is generated by the erase signal generator 22.

When the intermittent recording mode is instructed by the recording instruction key 18A, the control section 16A sets the intermittent / continuous recording selecting section 16B to the intermittent recording state and sets the recording / erasing signal selecting section 16C to the recording signal selecting state. Set. Thus, the recording mode is set, and the recording signal is recorded intermittently on the disk 1 using the recording head 14 and the recording / reproducing head 3, that is, with a standby period interposed. Writing is performed intermittently when the writing speed to the disk 1 is faster than the generation speed of the recording signal, for example, when the recording signal is compressed. In such a case, since the reading speed is higher than the reproducing speed, reading from the disk 1 is also performed intermittently.

On the other hand, the control unit 16A
When the continuous erasing mode is instructed by B, the intermittent / continuous recording selecting section 16B is set to the continuous recording state, and
The erase signal selector 16C is set to the erase signal selected state.
Thus, the erase mode is set, and the erase signal is recorded on the disk 1 continuously using the recording head 14 and the recording / reproducing head 3, that is, without providing a standby period. Since the writing of the erase signal to the disk 1 is performed continuously without providing a standby period, the erase operation is completed in a much shorter time than when the erase signal is intermittently written in the recording mode. In addition, since the invalid data is physically deleted instead of editing the TOC, security is high in terms of maintaining confidentiality and the like.

FIG. 2 is a block diagram showing an embodiment in which the present invention is applied to an MD type disk recording / reproducing apparatus. In the figure, reference numeral 1 denotes a magneto-optical disk capable of recording and reproducing,
Numeral 2 denotes a spindle motor for rotating the disk at a constant linear velocity. Numeral 3 denotes a light for optically reading information from the disk 1 (detecting a difference in Kerr rotation angle) or writing information magnetically on the disk 1. A pickup 4, a feed motor 4 for moving the pickup 3 in the radial direction of the disk 1, a high-frequency (RF) amplifier 5 for amplifying the output of the pickup 3, a rotation control 6 for the spindle motor 2, a feed control for the feed motor 4, and This is a servo controller for focus / tracking of the pickup 3.

The read system of the MD player includes a decoder section of an encoder / decoder 7 for decoding (demodulating) an output of the high-frequency amplifier 5, an address decoder 8 for detecting an address being reproduced from an output of the high-frequency amplifier 5, and an encoder. A memory 9 for temporarily storing the decoded output of the decoder 7 and its controller 10, an expansion unit of an audio compression / expansion unit 11 for expanding the output of the memory 9,
D / A for converting the extension output of extension section 11 into an analog signal
And a conversion unit 12. Encoder / decoder 7
Is an EFM (eight to fourteen modula)
) and CIRC (cross in
terleave reed-solomon code).

The writing system of the MD player includes an A / D converter 13 for converting an analog signal into a digital signal,
Audio compression / decompression unit 1 for compressing the converted digital signal so as to remove components unnecessary for the reproduction of the audio signal
1 and a memory 9 for temporarily storing a compressed signal
And a controller 10 thereof, an encoder section of the encoder / decoder 7 for encoding (modulating) an output of the memory 9, a recording head (magnetic head) 14 for writing a signal encoded by the encoder section to the disk 1, and a head drive thereof. And a circuit 15. Reference numeral 16 denotes a system controller for controlling the entire system, 17 denotes a display unit for displaying various information, and 18 denotes a plurality of operation keys for giving various instructions. The operation keys 18 include the recording instruction key 18A and the reproduction instruction key shown in FIG. 1, and the erasure instruction key 18B of the present invention is separately described.

The above-mentioned MD player is based on a CD player, and has a voice compression technique, an earthquake-resistant technique, a user recording function, and the like added thereto. The audio compression performed by the audio compression / decompression unit 11 is performed in such a manner that unnecessary data is thinned out using the characteristics of human hearing. For example, ATRAC (Adapti
ve Transform Acoustic Coding) realizes about 5 times information compression by utilizing the minimum audible characteristics of human beings and the masking effect. The decompression unit for restoring the compressed data combines the decode outputs of the encoder / decoder 7 and sequentially reproduces the digital waveform. With this method, a quality equivalent to a signal can be reproduced when represented by a level change in 16-bit steps and a sampling frequency of 44.1 kHz. In order to perform the data compression and decompression, a buffer memory 9 having an appropriate capacity is required on the signal processing circuit.

One feature that enhances the portability of the MD player is an anti-seismic technology for dealing with "sound skipping." This is realized by utilizing the difference between the read speed of the pickup 3 and the transfer speed of data input to the audio compression / decompression unit 11 and using the memory 9 as a data buffer. That is, the read speed of the pickup 3 is as high as 1.4 Mb (megabit) / s, whereas the transfer speed of data input to the audio compression / decompression unit 11 is as low as 0.3 Mb / s. Therefore, when the 1-Mbit memory 9 is used,
Data for about 3 seconds can be stored. Therefore, even if reading from the disk 1 is stopped due to vibration,
If it returns within seconds, the reproduced audio output will not "jump". The memory 9 is also used at the time of writing. In this case, the audio compression / decompression unit 11
The compressed data output at Mb / s is temporarily stored in the memory 9, read out, and then transferred to the encoder / decoder 7 at 1.4Mb / s. Since writing to the disk 1 by the magnetic recording head 14 is performed at 1.4 Mb / s, this writing is intermittent, using only a part of the entire processing time.

In an MD player, a read-only optical disk can be mounted on the disk 1.
The use of allows not only reading but also writing. For writing, laser light from the magnetic recording head 14 and the optical head (pickup) 3 is used. This writing method employs a magnetic field modulation method in which a laser beam having a constant intensity is applied to the lower surface of the disk 1 and a magnetic field modulated by write data is applied from the upper surface. When erasing invalid data with the MD player, the optical pickup 3 irradiates a laser beam having substantially the same or higher intensity as in the recording mode, and simultaneously turns off the recording signal of the magnetic recording head 14 or erases the recording signal. To overwrite this erase signal, thereby erasing the data in that portion. This erase mode is performed in a continuous operation. Hereinafter, this point will be described.

FIG. 3 is an explanatory diagram showing the above-described intermittent writing and continuous erasing. In this figure, the horizontal direction is the time axis,
The vertical direction indicates the flow of processing. The uppermost stage shows a transfer rate of 1.4 Mb / s digitized by the A / D converter 13.
When the audio data is compressed by the audio compression unit 11, it becomes compressed data having a transfer rate of 0.3 Mb / s shown in the second stage. This compressed data is stored in the memory 9, EFM
After reaching the magnetic recording head 14 via the encoder 7, the data is written to the disk 1 at a speed of 1.4 Mb / s in terms of audio data as shown in the third row. Therefore, a standby time longer than one writing time is interposed between writing operations. The above is the operation in the intermittent recording mode. On the other hand, in the erase mode, as shown at the bottom, the erase signal is continuously supplied at 1.4 Mb / s without providing a standby period.
Is written to the disc 1 at the speed of. In such a continuous erasing mode, the time until the completion of erasing is reduced to about 1/5 of that in the recording mode, and high-speed erasing becomes possible.

As the erasing signal, random data or a repetitive pattern of meaningless fixed data may be used. In the case of MD, the following signals can be used. (1) A signal whose level of a reproduced signal becomes sufficiently low during reproduction, for example, a signal of a high frequency; (2) EFM
A single frequency in the range of 1T to 11T or a combination signal of a plurality of single frequencies, (3) a signal having a prescribed EFM sync (2), (4) a substantially no signal (digital) EFM signals encoded so as to be zero or similar or almost no analog signals), (5) signals that are magnetized almost uniformly in the direction perpendicular to the disk surface when recorded, and the like. Further, continuous erasing can be performed by turning off the erasing signal. In this case, the magnetic recording head may be mechanically kept away from the disk.

Although the embodiment using the MD has been described above, the present invention is not limited to the MD. That is,
The present invention can be applied as long as intermittent recording is performed similarly to MD. The target disk is not limited to a magneto-optical disk. For example, when a phase change disk is used, an optical head that continuously erases the disk may be used.

[0024]

As described above, according to the present invention, in a disk recording / reproducing apparatus which performs intermittent recording / reproduction, data recorded on the disk is physically completely erased, and at a higher speed than at the time of recording. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a block diagram of an embodiment in which the present invention is applied to an MD recording / reproducing apparatus.

FIG. 3 is an explanatory diagram showing intermittent writing and continuous erasing;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc, 2 ... Spindle motor, 3 ... Optical pickup (optical head), 4 ... Sending motor, 5 ... High frequency amplifier, 6 ... Servo control unit, 7 ... EFM encoder / decoder, 8 ... Address decoder, 9 ... Memory, 10 memory controller, 11 audio compression / expansion unit, 12 D / A
Converter, 13 ... A / D converter, 14 ... magnetic recording head,
15: Head drive circuit, 16: System controller,
16A: control unit, 16B: intermittent / continuous recording selection unit, 16
C: record / erase signal selection unit, 17: display unit, 18: operation keys, 18A: record instruction key, 18B: erase instruction key,
21: recording signal generation unit, 22: erase signal generation unit.

Claims (2)

(57) [Claims] 1. A data compression method using a writing means .
That the waiting period is interposed the disc intermittently recorded data
Using the recording mode to write to the
A reproduction mode for intermittently reading reproduction data from the disk , and erasing the recording data on the disk continuously using the writing means without any intervening standby time. And a disk recording / reproducing apparatus comprising: 2. A data compression method using a magnetic recording head while irradiating a predetermined light from an optical head to a magneto-optical disk.
With intervening wait time by the intermittently recorded data
A recording mode for writing to a magneto-optical disk, and a waiting time due to data expansion is interposed between the optical head and the recording mode.
A read mode in which read data is read intermittently from the magneto-optical disk, and a recording signal of the recording magnetic head while irradiating the optical head with light that is substantially the same as or stronger than the recording mode. Do not leave it off or drive it with an erase signal to cause the data recorded on the magneto-optical disk to intervene a standby period.
And an erasing mode for continuously erasing the data.