JPS63269356A - Magneto-optical disk and its recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the accuracy of the recording and reproduction of a magneto- optical signal, by providing a first information track which records the magneto-optical signal, and a second information track provided along each track of the first information track and on which a control signal including address information at every track is recorded in advance on a magneto-optical disk. CONSTITUTION:A reloadable first information track 103 provided concentrically and spirally for a rotating central axis, and the second information track 104 provided along each track of the first information track and on which the control signal including the address information at every track is recorded in advance are provided. And by projecting a recording laser beam 206 on either the first information track 103 or the second information track 104, and projecting a reproducing laser beam 208 on the other of the first information track 103 or the second information track 104, the magneto-optical signal can be recorded and reproduced as performing the reproduction of the control signal. In such a way, it is possible to prevent interference between the magneto-optical signal and an information signal from being generated, and to record and reproduce the magneto-optical signal with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a erasable digital audio disc recorder having a compact disc function, and particularly relates to a disc on which a magneto-optical signal is recorded and a disc recorder having a compact disc function. The present invention relates to a device for recording and reproducing magnetic signals.

[Conventional technology]

FIG. 3 is a perspective view showing, for example, the structure of a magneto-optical disk used in a conventional device shown in Section 2-7-2 of the Proceedings of the 1985 Autumn Research Conference of the Acoustical Society of Japan. (101) A substrate made of Fi-doxy resin,
(102) is G6-Tb-IFe-G.

A recording medium layer made of an alloy, (103) has a width of 0.8 μm,
The group part (104) is formed in a spiral shape with respect to the center of rotation at a depth of 70 nm, and the land part (104) has a width of 0.8 μm separated by the group part (Yo3).
) This is a hard address part which is arranged in a concave shape in the Fi land part (104) and forms address information, and these constitute the magneto-optical disk (U00). CR) indicates the rotation direction of the disk (100). (200) is a laser beam that always follows the land portion (104), and emits a controlled minute output during playback, and operates as a playback beam suitable for polarized light playback; It emits a high modulated output and operates as a recording beam that is different from one reproduction beam.

(Ill) is a laser beam (20
This bit indicates an area where the magnetization of the recording medium # (102) of the disk (100) has been reversed due to thermal energy of #0) and an external magnetic field (not shown).

Next, the operation will be explained.

When the output of the laser beam (200) is 3.5 mW and the external magnetic field is applied to 4000 mW, the recording medium layer (102) is magnetized in the direction of the magnetic field.
), first perform an alignment operation to align the magnetic poles in the opposite direction to the magnetization direction during recording. ◎Rimari, apply an external magnetic field of 4000e with opposite polarity, and use a laser beam (200). The output of 3. Continuously make it follow the land portion (XO4) while maintaining I5mW. Afterwards, the external magnetic field is reversed and recording operation begins.

In the recording operation, the output of the laser beam (200) is 3.5
mW, and an output control circuit (not shown) is modulated so that the output is intermittent according to the recording signal.

In addition, when reproducing information recorded on this magneto-optical disk (U00), the output of the laser beam (200) is first narrowed down to 0'1 mWKt. In this case, the laser beam (200) reaches the recording medium layer (102) via a polarizer (not shown) in the optical path, and is reflected with the plane of polarization slightly rotated by the Kerr effect caused by the magnetic field, and is reflected by the analyzer ( (not shown) to a photodetector (not shown), and is a separate beam from the recording beam. At this time, the difference in the direction of the recorded magnetic field becomes a difference in the rotation direction of the polarization plane, and the amount of light received by the photodetector changes depending on the direction of the recorded magnetic field, so that the recorded information is reproduced. t+
, the laser beam (200) hits the eight-door address section (10
5) When tracking the vicinity, the amount of reflected light due to the optical recording difference of the laser beam (200) changes greatly between the land portion (104) and the bottom of the eight-door address portion (105). Laser beam for (200
) can read address information at the same time.

However, as shown in FIG. 4, for example, the address part (
Looking at the playback waveform of a disk (U00) on which address information was recorded by frequency modulation using IMHz as a clock and a 500 KHz rectangular wave as a magneto-optical signal, we can see that the address information was recorded in the address section (1015). ) Since it is difficult to reproduce magneto-optical signals that are not repeatedly recorded in the vicinity of Please make sure there are no problems.

[The interlayer point that the invention attempts to solve]

Conventional magneto-optical disks and their recording and reproducing devices are constructed as described above, so magneto-optical disks can be used as digital audio disks, but in order to always reproduce magneto-optical signals with high precision, complicated errors must be made. Problems include the need for a correction circuit and a magneto-optical disk with few defects, as well as restrictions on the recording interval of address information.

This invention was made with the intention of solving the above-mentioned problems, and is capable of rewriting data without requiring an error correction circuit or a high-quality magneto-optical disk, and without imposing restrictions on the recording interval of address information. It is an object of the present invention to provide a magneto-optical disk and its recording/reproducing device which can simultaneously reproduce a magneto-optical signal and a pre-recorded ratio control signal without error.

[A precautionary measure to resolve the problem]

The magneto-optical disk according to the present invention includes a rewritable first information track provided concentrically or spirally with respect to the central axis of rotation, and a rewritable first information track provided along each track of the first information track, and each trunk flil containing address information for each
Further, the magneto-optical disk recording/reproducing apparatus according to the present invention includes means for generating a recording laser beam and a reproduction laser beam, and a second information track on which a JgIl signal is prerecorded. means for switching between the recording laser beam and the reproduction laser beam so that when one of the information track and the second information track is irradiated with the recording laser beam, the other is irradiated with the reproduction laser beam; when recording, the reproduction laser beam is switched; A disk is driven and controlled based on a control signal obtained by irradiating the second information track, and the recording laser beam is irradiated to the first information track to record the magneto-optical signal, and the recording laser beam is used during reproduction. means for driving and controlling the disk based on the control signal obtained by irradiating the second information track with the reproducing laser beam, and reproducing the magneto-optical signal by irradiating the first information track with the reproducing laser beam. [Operation] The magneto-optical disk and the recording/reproducing device thereof according to the present invention include a rewritable first information track on which a magneto-optical signal is recorded on the magneto-optical disk, and a first information track provided along the first information track. and a second information track on which a control signal including address information for each track is recorded in advance.In addition, one of the first information track and the second information track is irradiated with a recording laser beam. However, by irradiating the other of the first information track and the second information track with a reproduction laser beam, the magneto-optical signal is recorded and reproduced while reproducing the control signal. The magneto-optical signal can be recorded and reproduced with high accuracy without interference between the signal and the information signal.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
FIG. 2 is an enlarged perspective view of the magneto-optical disk of the present invention, and (106) shows the land portion (yu 04) of the disk (loo). ), address information corresponding to each group part (103) is encoded at one place per rotation and is formed in a concave shape, and (107) is also a land part ( 104) is a speed information section formed in a concave shape and encoded with speed information for rotating the disk (YOO) at a constant linear speed at approximately constant intervals.

(20U) is a changeover switch that switches the device between the recording state and the playback state; (202) is a control circuit that outputs various control signals according to the signals from the changeover switch (20U);
3) is a recording circuit that processes a signal to be recorded in the group section (U03) of the disk (Yoo), (204) a reproduction circuit that processes the signal reproduced from the group section (103) of the ij disk (100), (205) emits high output laser power to the group section (U03) of the disk (100) in accordance with the signal from the recording circuit (go3) in the recording state, and emits a narrowed output laser power to the land section in the playback state. (104) and land part (104).
) A recording head (20) that can read the signals of the address information section (106) and speed information section (YUO)), (20) is a recording laser beam from the recording head (205), (20)
) emits a reproduction laser beam (2os) to the group part (103) of the disk (YOO) through a polarizer (not shown) in the reproduction state, and passes the reflected light to an analyzer (not shown). A photoelectric converter (not shown) is reached through the photoelectric converter (not shown) to obtain a reproduction signal by the Kerr effect, and in the recording state, the reproduction laser and one beam (208) are irradiated onto the land portion (4o4). ) is a playback head that can read signals from the address information section (U06) and speed information section (U0)). (209) is the recording laser f-beam (2
! The tracking circuit A1 (210) for 06) is the tracking circuit B for the reproduction laser beam (20B), and the respective tracking circuits (209).

(210) The control signal output from the F1 control circuit (202) causes the corresponding recording laser beam (2
06) and the reproducing laser beam (20B) on the group part (U03) and the land part (1
04). (21X) is a movable table on which the recording head (205) and reproducing head (2Q)) are placed and fixed and can be moved in the radial direction from the center of the disk (100). (2
The motor (214) driven by the motor A (214) is an address detection circuit that processes the signal from the address information unit (106) and outputs a signal to the motor A (212) to move the moving platform (211) to a desired position. (215) is the disk (1
Motor 1, which rotates the disk (216) #:, processes the signal of the speed information section (20γ), and rotates the disk (100).
This is a speed control circuit that outputs a signal to motor B (215) so that the linear velocity of the part where speed information is read is always at a predetermined value. As shown above, an orientation operation is performed to align the polarities of the recording medium layer (102i). In this case, it is natural that a bias magnetic field is applied near the recording laser beam (206) by a magnet (not shown).

Next is the recording operation, but first, selector switch (201)
puts the entire device into recording mode. When the recording state is entered, the connection state of each circuit is changed to the recording circuit (2) as shown in Figure 1.
03) and the recording head (205) are connected, and the address detection circuit (214) and speed control circuit (216) are connected to the reproducing head (207), and the recording laser beam (go6) is directed to the group section (103). The reproduction laser beam (20B) follows the land portion (104).
When a signal to be recorded is input from the recording circuit (203) to the recording head (205) in a state of power strength or weakness, the recording laser beam (206) is tracked on the group section (103) under the control of the tracking circuit (209). At the same time, the recording medium layer (102) is intermittently heated, so that the boron pole of the heated portion is reversed and the input signal is recorded. In this case, the rotational speed of the disk (loO) is
o) e Speed information section (107) #Reproduction laser beam (20B) #Reproduction head (20)), speed control circuit (
216) It is controlled to a constant II speed by a speed control system consisting of p motor B (2 units 5). In addition, when the changeover switch (201) is set to the playback state, the playback circuit (20
4) and the playback head (207) are connected, and the address detection circuit (2U4) and speed control circuit (J6) are connected to the recording head (20B), and the recording laser beam (2U4) and the recording head (20B) are connected.
06) follows the land portion (Y04), and the reproduction laser beam (20B) follows the group (103).

Since the reproducing laser beam (20B) follows the group portion (103) in this way, the signal recorded on the disc (100) is output from the reproducing circuit (204). In this case as well, the recording laser beam (206) tracks the land portion (104) with minute power and the speed information portion (104)
Since the speed information of 07) is read out, the rotation of the disk (U00) is controlled at a constant linear velocity.

Here, in the above embodiment, two types of laser beams are used. During recording, the recording laser beam (206) follows the land portion (104), and during reproduction, the reproduction laser beam (20B) follows the land portion (104). As shown above, the laser beam that follows the land part (U04) is fixed, and the connection with the head that follows the group part (U03) is made by the reproducing circuit (204) or the recording circuit (203).
) may be used to record and reproduce magneto-optical signals.

However, in this case, three types of laser beams, a recording beam, a magneto-optical signal reproducing beam, and a control signal reproducing beam, are required, which causes problems such as making the apparatus complicated and large.

This requires complex functions such as recording beams and polarized beams that require high power, and cannot be used for magneto-optical signal reproduction beams that cannot output high power, but a small amount of power is good for control. It is easy to use both the signal reproduction beam and the recording beam whose power can be easily narrowed down.
Similarly, it is easy to use both the control signal reproducing beam and the magneto-optical signal reproducing beam. In the above embodiment, the land section (xo4) has an address information section (106) and a speed information section (10'F). Although the address information section (106) alone is sufficient, other necessary control signals may be added.

In addition, in the above embodiment, a control signal including address information was arranged with a concave code in advance in the land part (xo4) to show a precaution, but a control signal with a convex code was arranged in the group part (x03). A magneto-optical signal inputted from the outside may be recorded on the land portion (104), or a through hole may be provided in the disk.

Further, in the above embodiments, a case has been described in which a material having a magneto-optic effect is used for the recording medium, but a phase change material or other rewritable material may also be used, and the same effects as in the above embodiments can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a first information track for recording a magneto-optical signal, and a control signal provided along each track of the first information track, and a control signal including address information for each track is recorded in advance. Since a second information track and a second information track are provided on the magneto-optical disk, one of the first information track and the second information track is irradiated with a recording laser beam, and the first information track and the second information track are recorded. The other of the two is irradiated with a reproduction laser beam to record the magneto-optical signal without reproducing the control signal.
Since this method allows playback, it is possible to realize a high-performance rewritable digital audio system without requiring an error correction circuit or a high-quality magneto-optical disk, and without imposing restrictions on the recording interval of control signals. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a recording/reproducing apparatus for a magneto-optical disk according to an embodiment of the present invention, FIG. 2 is an enlarged perspective view showing a magneto-optical disk of the invention, and FIG. FIG. 4, which is an enlarged perspective view of the magnetic disk, is a reproduction signal waveform diagram obtained by a conventional apparatus. In the figure, (zoo) is a magneto-optical disk, (yu02)
is a recording medium layer, (tos) is a group part, (104) is a land part, (106) is an address information part, (lo)) is a speed information part, (201) is a changeover switch, (202) is a control circuit, (203) t;j recording circuit, (204) reproducing circuit, (205) recording head, (206) recording laser beam, (20'i') reproducing head, (20B)
is the reproduction laser beam, (209) is the tracking servo circuit A, (210) is the tracking servo circuit 1
, (211) is a moving table, (212) is a mortum, (21
3) is a screw, and (214) is an address detection circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] (1) In a disk on which magneto-optical signals are recorded, a rewritable first information track provided concentrically or spirally with respect to the rotation center axis and on which the magneto-optical signals are recorded. and a second information track provided along each track of the first information track, on which a control signal including address information for each track is prerecorded. (2) Claim 1, characterized in that the control signal includes speed information for controlling the rotation of the disk at a linear speed.
Magneto-optical disk as described in section. (3) Claim 1 or 2, characterized in that the control signal is recorded by changing the shape of the disc.
Magneto-optical disk as described in section. (4) the first information track consists of one of grooves and hills alternately formed concentrically or spirally on the disk;
4. A magneto-optical disk according to claim 3, wherein the second information track is comprised of the other of the groove and the hill. (5) A rewritable first information track provided concentrically or spirally with respect to the rotation center axis, and provided along each track of this first information track, containing address information for each track. and a second information track on which a control signal is prerecorded.
A device for recording and reproducing a magneto-optical signal on an information track, the generating means generating a recording laser beam and a reproduction laser beam, and irradiating one of the first information track and the second information track with the recording laser beam. a switching means for switching between the recording laser beam and the reproduction laser beam so as to irradiate the reproduction laser beam onto the other of the first information track and the second information track; The irradiation position of the recording and reproducing laser beam is controlled based on the control signal obtained by irradiating the recording laser beam to the first information track, and the recording laser beam is irradiated to the first information track to record the magneto-optical signal. controlling the irradiation positions of the recording and reproducing laser beams based on the control signal obtained by irradiating the second information track with the recording laser beam, and irradiating the first information track with the reproducing laser beam; and a control means for reproducing the magneto-optical signal. (6) A recording/reproducing apparatus for a magneto-optical disk according to claim 5, wherein the generating means comprises a recording head for generating a recording laser beam and a reproducing head for generating a reproduction laser beam. (7) A patent in which the switching means includes a changeover switch that changes the inside of the device between a recording state and a playback state, and a recording and playback tracking circuit that controls the irradiation positions of the recording and playback laser beams, respectively, by signals from the changeover switch. A recording/reproducing apparatus for a magneto-optical disk according to claim 5 or 6. (8) The control means is movable in the radial direction with respect to the central axis of rotation, and includes a moving table on which the generating means is placed and fixed, a motor that drives the moving table with a screw, and reproduction from a second information track. an address detection circuit that processes address information in the control signal and outputs a signal to the motor to move the moving platform to a desired position; and a recording circuit that processes a magneto-optical signal to be recorded on the first information track. 8. A recording/reproducing apparatus for a magneto-optical disk according to any one of claims 5 to 7, comprising: a reproducing circuit for processing a magneto-optical signal reproduced from the first information track.