JP2748444B2 - Magneto-optical recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording apparatus, and more particularly to a magneto-optical recording apparatus capable of intermittently irradiating a magneto-optical disc with a light beam and performing overwriting. It is suitable for application.

B. Summary of the Invention The present invention provides a magneto-optical recording apparatus that samples a reproduction signal a plurality of times and reproduces data immediately after recording during a period from the end of irradiation of a light beam to the end of irradiation. Even if the spot is scanned at high speed, the data immediately after recording can be surely verified.

C Prior Art Conventionally, this type of magneto-optical recording apparatus has been provided with a collation function (so-called verify function) for confirming whether or not valuable data has been reliably recorded.

That is, in the magneto-optical disc device, a light beam is applied and a predetermined modulating magnetic field is applied, thereby forming a pit on the magneto-optical disc sequentially oriented by the modulating magnetic field.

Subsequently, in the magneto-optical disc device, after waiting for one revolution of the magneto-optical disc, a reproduction signal is obtained from the area where the pits are formed, thereby confirming whether or not the data has been recorded in the area without apologies. .

Thus, by switching and irradiating one light beam in the recording and reproduction modes in the cycle of one rotation of the magneto-optical disk, it is possible to verify whether or not data has been reliably recorded.

D Problems to be solved by the invention However, in this type of magneto-optical disc device,
In order to verify the recorded data, after recording the data, it is necessary to wait until the magneto-optical disc makes one revolution,
The access time becomes longer as a whole.

Therefore, the light beam is intermittently radiated at the recording mode intensity to sequentially form pits, and the intensity of the light beam is switched to the reproduction mode during a period from the irradiation of the light beam to the subsequent irradiation. A method of obtaining a reproduced signal from a pit immediately after formation by irradiating the pit with light has been proposed (Japanese Patent Application No. 62-87563).

According to this method, since the data immediately after recording can be collated, the access time can be shortened accordingly.

However, in this method, since the recording principle of the magneto-optical disk is thermomagnetic recording, if the rotation speed of the magneto-optical disk is increased and the scanning of the subcutaneous spot is accelerated, it may be difficult to verify the data. However, there were still problems that were insufficient for practical use.

That is, in the magneto-optical disc apparatus, by irradiating a light beam to raise the temperature of the pit forming position above Kiyuri temperature T _c.

In this case, when the irradiation of the light beam is completed, the temperature of the pit forming position drops, and the pit forming position is oriented in the direction of the modulation magnetic field when the pit crosses the temperature _Tc .

Therefore, at the pit forming position, the pit is formed by being oriented in the direction of the modulation magnetic field only after the temperature of the pit forming position falls below the key temperature _Tc, and the data immediately after recording is actually reproduced. In this case, it is necessary to wait for the temperature at the pit forming position to drop below the key temperature _Tc .

Therefore, when the rotation speed of the magneto-optical disk increases,
When the temperature of the pit forming position falls below the key temperature _Tc , the light beam irradiation position is largely moved in the direction of the pit forming position following the pit forming position, and a reproduced signal is obtained from the pit immediately after the formation. It becomes difficult.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a magneto-optical recording apparatus capable of securely collating data immediately after recording even when scanning an optical spot at high speed.

In the present invention for solving means above problems to solve E problems, at the timing of a predetermined reference clock signal S _CK, sequentially intermittently recording level on the magneto-optical disk 4 light Supotsuto SP ₁ and forming, by the polarity applies a modulated magnetic field H _M for reversing in accordance with the reference clock signal recording information in synchronism with the S _CK, in the magneto-optical recording apparatus 1 for magnetically recording the record information in the optical magnetic disc 4, a light beam emitting unit 8 for emitting a light beam LA1 of forming a light Supotsuto SP1, the reproducing means 13 to obtain a reproduced signal S _OUT based on the light beam LA1 reflected from the magneto-optical disk 4, during recording, the recording level At a second timing t2, which is delayed by a predetermined time from the first timing t1 at which the light beam LA1 was irradiated, the magneto-optical data having reached the temperature equal to or higher than the query temperature by the light beam LA1 at the recording level. Together to obtain a first reproduced signal S _OUT based on the reflected light beam by irradiating the reproduction level of the light beam LA1 the disk surface, the third timing t3 when a predetermined time delay from the second timing t2 Irradiating the light beam LA1 at the reproduction level to the magneto-optical disc surface below the Kyuri temperature to control the light beam emitting means 8 so as to obtain the second reproduction signal _SOUT based on the light beam reflected. Control means 15 and second and third timings
At t2 and t3, sampling means 18, 1 for sampling the reproduction signal S _OUT obtained by the reproduction means 13, respectively.
9 and arithmetic processing means 25 and 26 for reproducing the recorded information recorded on the magneto-optical disk 4 based on the output signals of the sampling means 18 and 19.

F action If the reproduction signal S _OUT obtained in the reproduction mode (H _R ) is sampled a plurality of times, the reproduction signal S _V for the pit P ₁ immediately after formation is obtained based on the resulting sampling output signals S _GOUT1 and S _GOUT2. Obtainable.

G Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a magneto-optical disc device as a whole, and a magneto-optical disc 4 in which a perpendicular magnetization film 3 is mounted on a transparent protective substrate 2 made of, for example, polycarbonate, glass or the like, is provided with a spindle motor 5. To rotate at a predetermined rotation speed.

On the magneto-optical disk 4, a servo pattern of a sample format is formed in advance in servo areas arranged at predetermined angular intervals, and a reference for recording and reproduction is based on a reproduction signal obtained from the servo pattern of the sample format. A clock signal is obtained.

That is, in the magneto-optical recording device 1, the light beam LA1 emitted from the semiconductor laser 8 is
The light beam is condensed on the magneto-optical disk 4 via the polarizing beam splitter 10 and the objective lens 11, and the reflected light beam of the light beam LA1 is reflected by the objective lens 11, the polarizing beam splitter 10
The light is guided to an optical detector 13 via a condenser lens 12.

Clock signal generating circuit 14 receives the reproduced signal S _OUT obtained from the optical Deitekuta 13, these on the basis of a reproduction signal obtained from the servo region, the recording and modulation circuit 30 and the control circuit the reference clock signal S _CK for reproduction Output to 15.

Modulation circuit 30 is supplied to a head drive circuit 20 synchronizes the S ₀ exiting an externally input to the reference clock signal S _CK.

On the other hand, the control circuit 15 outputs the control circuit _SC1 to the laser drive circuit 17, and outputs the reference clock signal S
_A tracking error signal is obtained along with _CK , thereby
As shown, successively recording track pit P ₁ formed on, P ₂ ...... on the optical Supotsuto SP1 a is tracking controlled so as to Jiyasu Toto Raţ King.

Further, the control circuit 15 controls the laser drive circuit 17 and the gate circuit 1 according to the operation mode of the magneto-optical disk device 1.
The operations 8 and 19 are switched and controlled, so that data immediately after recording can be collated in the recording mode.

That the control circuit 15, at a recording mode as shown in FIG. 3, switches the light beam LA1 emitted from the semiconductor laser 8 in a region other than the servo area on the recording time of the optical intensity H _W, the reference clock signal S _CK in (FIG. 3 (a)) rises timing, irradiated during the period T _W (FIG. 3 (B)).

Thus, at time t1 of the start of irradiation of the light beam LA1, the optical Supotsuto SP1 is formed on the pit P ₁ previously formed (FIG. 2 (A)), the temperature T a Kiyuri temperature T _C of the pit forming position Start up as above (FIG. 3 (C)).

Therefore, at the time point t2 when the irradiation of the light beam LA1 ends,
By the temperature T of the pit forming position rises above Kiyuri temperature T _C, erased magnetized pattern of pit P _1, which is preformed, is made thereby to be able to erase the data recorded on the pit forming position ing.

Further control circuit 15 at time t3 during the period from the time point t2 at which irradiation of the light beam LA1 is finished to a temperature T of the pit forming position falls below Kiyuri temperature T _C, the light beam LA
1 is irradiated by switching the time of the light intensity H _R playback.

Therefore, at the time point t3, the optical spot SP1 is formed on the pit forming position (P ₁ ) where the data has been erased and on the pit P ₂ where the data has not yet been erased (FIG. 2 (B)).
Thus through the light Deitekuta 13, it has been made to obtain only the reproduction signal from the pit P _2.

That represents the signal level of the reproduced signal S _OUT when the light Supotsuto SP1 is properly irradiated with pits P ₂ in S _P2, the time t3
In represents the reproduction efficiency with which light Supotsuto SP1 irradiates a portion of the pit P ₂ at A _2T3, equation S _OUT = _A 2t3 S _P2 reproduction signal represented by the signal level at ...... (1) S _OUT Is obtained.

Further, after the temperature T at the pit forming position falls below the query temperature T _C , the control circuit 15 continues the light beam LA1.
At time t4 during the up but rises at the light intensity at the time of recording, the light beam LA1 the irradiation with reproduction light intensity H _R, thereby pit forming position (P ₁₎ and the subsequent pit P ₂ light Supotsuto on SP1
Is formed (FIG. 2 (C)).

In this case the pit forming position (P _1), via a magnetic head 21 driven by the head driving circuit 20, a modulation magnetic field H _M corresponding to the recording data is adapted to be applied, thereby the modulated magnetic field H A pit oriented with a magnetic field determined by _M
P _1N is formed.

Accordance connexion, at time t4 via the optical Deitekuta 13, the following equation _{S OUT = A 1t4 S P1N +} A 2t4 S P2 reproduced signal pit P _1N and P ₂ represented by ...... (2) S _P1N and S A reproduction signal S _OUT in which _P2 is mixed is obtained.

Here S _P1N represents the signal level of the reproduced signal S _OUT when the light Supotsuto SP1 is properly irradiated with pits _{P 1N,} A 1t4 and
A _2T4 represents the regeneration efficiency of each pit P _1N and a reproduction signal obtained from the P ₂ when the light Supotsuto SP1 at time t4 is irradiated with part of the pit P _1N and P _2.

Here, the regeneration efficiencies A _1t4 , A _2t3, and A _2t4 are the respective pits P _1N
And changes according to the size of the light Supotsuto SP1 formed on the P _2, the pits P _1N and light Supotsuto S formed over P ₂
The larger the size of P1, correspondingly each pit P _1N and P ₂
The signal level of the reproduced signal obtained from is also increased.

Therefore, from the expressions (1) and (2), from the time t3 to the time t4
Until, the light Supotsuto SP1 will compensate for changes in the reproduction efficiency of the pit P ₂ by scanning in the direction of the pit P _2, point
If the difference signal between the reproduced signals S _OUT at t3 and t4 is obtained,
It can be seen that only capable of detecting reproduction signal obtained from the pit P _1N.

That is, using the reproduction signal of the pit P ₂ obtained at time t3, pits obtained at t4 P _1N and P ₂ of the reproduced signal S
From the reproduced signal S _{OUT of P1N} and S _P2 are mixed, if so removing the reproduced signal component of pits P _2, it is this which extract only a reproduction signal obtained from the pit P _1N.

That is, the control circuit 15 controls the gate circuits 18 and 19 to
Gate signal whose signal level rises at t3 and t4 respectively
Outputs S _G1 and S _G2 (FIG. 3 (D) and (E)), captures the reproduced signal S _OUT of the time t3 and t4 to the gate circuits 18 and 19.

The gate circuit 18 _corrects the signal level of the reproduction signal S _{OUT at} the time point t3 to a signal level represented by the following equation: S _GOUT1 = A _2t4 S _OUT = A _2t4 A _2t3 S _P2. Output to the circuit 25.

On the other hand, the gate circuit 19 determines the signal level of the reproduction signal S _{OUT at} the time point t4 by the following equation: S _GOUT2 = A _2t4 S _OUT = A _1t4 A _2t3 S _P1N + A _2t4 A _2t3 S _P2. The signal is corrected to the indicated signal level and output to the differential amplifier circuit 26.

Delay circuit 25 has a delay time period T _DL from the time point t3 to time t4, the time t3 this from the signal level is corrected
And the reproduced signal of t4 at the same timing as the differential amplifier 26
Output.

Therefore, in the differential amplifier circuit 26, (3) and (4)
From the equation, it is possible to obtain a difference signal S _SA expressed by the following equation: S _SA = A _1t4 A _2t3 S _P1N (5), and set the amplification factor of the differential amplifier circuit 26 to a predetermined value. by correcting the signal level of the difference signal, it is possible to obtain a reproduction signal of the pit P _1N.

Thus through the differential amplifier circuit 26, even when the light Supotsuto SP1 is scanning at high speed, it is possible to obtain a Berifuai signal S _V consisting represents data immediately after recording.

Thus the control circuit 15, the period T to the irradiation of the light beam LA1 by the light intensity H _W at the time of recording is irradiated followed after completion
_{During R} , the control circuit for irradiating the light beam LA1 by switching to the reproduction mode is configured, whereas the gate circuits 18 and 19 are
During the period T _R, constituting a sampling means a plurality of times sampling of the reproduced signal S _OUT.

Further differential amplifier circuit 26, constructed in accordance with an output signal S _GOUT1 and S _GOUT2 gate circuits 18 and 19, the pit P _1N formed by irradiation of light beam LA1 the arithmetic processing means for outputting the reproduced signal S _V I do.

In the above configuration, the light beam LA1 is, after being irradiated with light intensity H _W at the time of recording at time t1, is illuminated with playback light intensity H _R at time t3 and t4.

Thus, data recorded on the pit P ₁ is erased by irradiation of light beams LA1 time t1, the pit forming position (P
₁₎ is rewritten to the data determined by the modulated magnetic field H _M.

On the other hand, with the light beam LA1 emitted at the time t3,
Data light Supotsuto SP1 is formed on the pit formation position (P ₁₎ and the subsequent data is still unerased pit P ₂ erased, thereby only the reproduction signal for the pit P ₂ from the optical Deitekuta 13 is obtained.

Furthermore, a light beam LA1 emitted at time t4, data pits P _1N and subsequent data light Supotsuto on pits P ₂ unerased yet SP1 rewritten is formed, thereby via the optical Deitekuta 13, reproduction signal is obtained reproduced signal pit P _1N and P ₂ are mixed.

The reproduction signal S _OUT is supplied to the gate circuit 18 at each time point t3 and t4.
And incorporated into the 19, is weighted so as to cancel the reproduction signal component from the pit P ₂ is output to the differential amplifier circuit 26, thus through the differential amplifier circuit 26, to extract the reproduction signal of the pit P _1N Can be.

According to the above configuration, immediately after data is recorded, a light beam is intermittently radiated at the light intensity at the time of reproduction, and a reproduction signal component of a subsequent pit is removed from a reproduction signal obtained as a result. Even when is rotating at a high speed, the recorded data can be reliably collated.

In the above-described embodiment, the case where the light beam is intermittently irradiated with the light intensity at the time of reproduction and the reproduction signal is sampled a plurality of times in synchronization with the irradiation of the light beam has been described. not only, as shown in FIG. 4, it may be irradiated continuously between light beam a period T _R in the light intensity during reproduction.

Further, in the above-described embodiment, the case where the reproduction signal is sampled at times t3 and t4 before and after the temperature of the pit formation position crosses the query temperature has been described. Sampling is performed, and a reproduced signal of a pit immediately after formation may be obtained from a sampling output signal obtained as a result.

Further, in the above-described embodiment, the case where the present invention is applied to a magneto-optical disk apparatus has been described. However, the present invention is not limited to this, and the optical spot is scanned at a high speed to record data. It can be widely applied to magnetic recording devices.

H Advantageous Effects of the Invention As described above, according to the present invention, after irradiating the recording level light beam at the first timing, the reproduction level light is applied to the magneto-optical disc surface which has reached the temperature of the query or higher at the second timing. The first reproduction signal is obtained by irradiating a beam, and the second reproduction signal is irradiated by irradiating a light beam at a reproduction level to the magneto-optical disk surface which is at a temperature lower than the query temperature at a third timing thereafter. By obtaining the reproduction signal of, the data immediately after recording can be reliably detected based on the first and second reproduction signals.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing a magneto-optical disk device according to an embodiment of the present invention, FIG. 2 is a schematic diagram used for explaining its operation, and FIG. 3 is a signal waveform diagram used for explaining its operation. FIG. 4 is a signal waveform diagram showing another embodiment. 1 ... Magneto-optical recording device, 4 ... Magneto-optical disk, 8 ...
Semiconductor lasers, 15 delay circuits, 18, 19 gate circuits.

Claims (1)

(57) [Claims] 1. At a predetermined reference clock signal timing,
A recording level light spot is formed on the magneto-optical disk sequentially and intermittently, and a modulating magnetic field whose polarity is inverted in accordance with the recording information in synchronization with the reference clock signal is applied to the magneto-optical disk. In a magneto-optical recording apparatus for magnetically recording recorded information, a light beam emitting means for emitting a light beam forming the light spot; a reproducing means for obtaining a reproduced signal based on the light beam reflected from the magneto-optical disc; At the time of recording, the first beam irradiated with the light beam of the recording level
At a second timing which is delayed by a predetermined time from the timing described above, the light beam at the reproduction level is reflected by irradiating the light beam at the reproduction level to the magneto-optical disc surface which is at or above the query temperature by the light beam at the recording level. A first reproduction signal is obtained based on the light beam, and at a third timing delayed by a predetermined time from the second timing, the light having a reproduction level is applied to the magneto-optical disk surface having a temperature equal to or lower than the query temperature. Control means for controlling the light beam emitting means so as to obtain a second reproduction signal based on the light beam reflected by irradiating the light beam; and at the second and third timings, the reproduction means Sampling means for sampling the reproduced signal obtained by Magneto-optical recording apparatus is characterized in that comprises an arithmetic processing means for reproducing the information recorded on the magneto-optical disc.