DE4293957C2 - Magneto=optical disk appts. capable of ultra-high density recording - Google Patents

Abstract

The appts. includes a device for controlling the shape of a recording pulse waveform, for varying the recording density to the disk in accordance with a disk position, and for conducting test recording prior to recording of user data. The appts. further includes a device for eliminating fluctuation of an edge position due to thermal interference between pits and for reducing the fluctuation of the edge position resulting from the change of an external environmental condition.

Description

The present invention relates to an optical disk storage device and a method for recording and reproduction of optical information according to the Oberbe handles the independent claims.  

In connection with the progress of modern informa tion society has a need for file storage with high capacity and high density increased more and more. Attention is on the optical record has been addressed, which is a means by which the above need can be met. The memories from Read-only type, write-once type and how the writable type are consecutively in practical Came into use and are already used in applications det, in which their peculiar characteristics are effective can be used. Of these recently, in particular the rewritable memory with magnetoopti scher recording come into practical use. The investigations and developments in many Research institutes are advancing to memory pro products with magneto-optical recording of the next ge to realize the generation. As one of the main investigators directions for the realization of such Pro products, the super-dense recording can be mentioned. As a procedure for realizing the record with Various methods have been proposed for super density where the track spacing is reduced, an interval of the magnetic domain of the record is reduced, short wavelength light is used the information in the marginal area of the magnetic Do man of the record is recorded, and the like more. It is considered effective, a combination to use these procedures.

As a means of recording a digital Si An optical medium stands on a recording medium Disk space available. With an optical disc is a laser beam through a lens on the record  surface is focused, the intensity of the laser beam according to the information to be recorded changes are in the area that the laser beam be emits either the reflectivity of the record film or in the case of magneto-optical recording by external magnetization or the like changed the magnetization direction, whereby the Infor mation is recorded. When playing the up recorded information, a laser beam is used, whose intensity is weaker than the intensity of the the recording of the laser beam used is. There will either be a change in the amount of light from the light reflected from the recording film or the Dre hung the plane of polarization by a difference in the direction of magnetization is detected, where is reproduced by the recorded information. A recording density is mainly due to the Size of the light spot of the laser beam is determined on the recording surface is focused. Because the light spot size is currently around 1 µm, it can be large dense recording can be realized with a density, which is about ten times that of the magnetic one Plate is.

On the other hand, mark length recording procedure in which the information at the positions of the Front and back of the by modulation the record of irradiation light output marker is a means that is used for realizing a high recording density sam is because two or more data in one record markings can be recorded.

In the mark length recording method for the Recording and / or playback of information on the  optical disc / from high density optical disc are used in the recording and playback of the Data different types of signal processing leads to high reliability of information realize.

If in general z. B. the irradiation light output when the recording is low, the shape of the up Drawing mark that is easily formed, unstable. If the linear recording speed fluctuates, the heat introduced into a unit area fluctuate quantity and a heat distribution, so that the shape of the on Drawing mark fluctuates. Because in reality the stable shape of the recording mark formed and the Recording and playback must be performed is described in "Application of Pit Edge Recording On PbTbSe Thin Film, "The General National Conference of the 70th Anni versary of the Founding of the Institute of Television Engineering of Japan, The Collection of Lectures and Pa pers, pages 4 to 176, a setting made, such that the recording irradiation light pulse et what is set larger and that when recording the laser pulse length is set to a short value, so the mark length is no longer than one with the linear velocity is the same setpoint, or that during playback the pulse length in the signal is reduced after the completion of the binary conversion, or similar.

The shape of the recorded mark generally depends mean recording sensitivity and egg Thermal conductivity of the recording medium and an intensity distribution, a wavefront aberration or the like of the one used for recording, focused laser beam. Their characteristics change  change when there is a combination of disk space device and the recording medium changes. Further the level of the irradiation light output changes the record on the part of the facility over time. Such a phenomenon occurs with an amount of fluctuation a certain area certainly even in that case in which an automatic control mechanism of the La power (APC) is provided. The recording and Playback characteristics also fluctuate due to one such factor. Such a fluctuation has a swan the recording mark length when recording voltage and a fluctuation in the pulse interval of the re result signals during playback.

Therefore, when the device is sent the record correction amount and the recording light power have been preset to predetermined values their set specifications by measuring the on Drawing and playback characteristics for an An number of combinations of the recording medium and the Storage device determined. To ensure that in all respects at the time of registration cases one by different combinations true fluctuation range of the recording and how Ensuring delivery characteristics is a concern Lich a high tolerance preeseed the recording density hen, causing damage to the recording density.

Therefore, the extent of the variation in the characteristics due to the combination of the recording medium and the Record device and a high on Realizing a drawing density is a procedure been beaten in advance with a test sample is drawn and the information for hiring the recording conditions by the playback signal  is obtained. For example, in JP-A-61- 239441 disclosed establishing the level of the irradiation light output that a pre-recorded represents the given value. In the JP-A-61- 74178 device disclosed is a the record voltage pulse width of the given setting wear set. The one disclosed in JP-A-63-304421 Both the above level of irradiation will be set up light output as well as the above given input actuating amount and a mechanical adjustment coefficient set together during playback.

Since the optical disc is fundamentally based on the heat diff fusion-based recording process, be stands a phenomenon (the mutual heat below disorder is called), such that the shape of the on Drawing mark due to diffusion of heat division changes, which by several recording pulses before and after the corresponding record mark is caused. Such a phenomenon also has playback a fluctuation in the pulse interval of the Playback signals. So in order to record it is necessary to carry out the optimal correction dig, the influence of mutual heat disturbance too consider. As a countermeasure for such a problem is used in the recording method described in JP-A-63- 48617, each recording pulse whose Width has changed according to the interval up to to the immediately preceding recording pulse changes.

According to the conventional recording method as described in JP-A-3-22223 is a record Code train of the recording mark converted into pulses delt and becomes a number of the length of the record  Codezuges corresponding pulse trains formed and according the length of the pulse train and the length with opposite set phase of the recording code train that di right before the recording code train with this width is present, controlled, the impulse train in three ab cuts and becomes the pulse width of each Pulse changed, causing the recording to run becomes.

With regard to the recording density in the radial direction tung is for a medium with a write-once film already in Japanese Patent Application No. 2-133819 an optical disk storage device in detail be in which the track on the plate in Zo NEN is divided, which in turn consists of several tracks and where the information is recorded in zones such that the same linear recording te is obtained. In such a facility but the linear density in each zone on the plate we against the recording and reproducing characteristics of the once writable film is not on a given Value can be set. The linear recording density in the zone of the inner groove of the plate is higher than the one in the zone of the outer groove.

In the above conventional technique, that point paid no attention that a fluctuation in the Recording sensitivity of the recording medium due to a fluctuation in the film thickness of the recording medium or due to fluctuations in the environment exercise temperature occurs. There is a problem that ei ne reduction in recording capacity occurs because the recording mark is not accurate can be controlled.  

In the above conventional techniques, there are following procedure of setting the recording im pulse width corresponding to the interval up to the immediate previous recording pulse the following problems me:

If the user has a high density recording with a Desires to realize degree in which the size of the shape the record mark and the interval between the recording marks equal to or less than that Size of the laser light spot are on the record film is an area in which the ge mutual heat disturbance of the optical disc an on river, larger than the shortest record mark length. This means that when determining the edge position a certain record mark because of the dif sound heat the lengths of the multiple recordings pulse intervals of the recording irradiation light pulses exert an influence so that even if the up drawing pulse with the same length is used, the Edge position itself due to a combination of the front recording positions most changes over time. Especially with an up drawing medium in which the recording is sensitive speed is high compared to the intensity of the laser beam and information even with low laser power can be drawn is the thermal conductivity in general mean high, there is also an area in which influence the mutual heat disturbance is exerted, great.

According to the above procedure for setting the recording voltage pulse interval is also independent of the up drawing conditions at the time of hiring the preset amount related to the set amount Value used. Therefore, the fluctuation of the up  Adjustment amount relating to drawing characteristics not be changed, instead only a appears Adjustment amount that is just an amount of deviation the recording characteristics of those at the time corresponds to the setting, as a setting error, see above that an exact setting cannot be carried out.

On the other hand, according to the method in which the Infor mation for setting the recording conditions is obtained, this setting based on a Unit amount of the recording irradiation light power or the recording pulse width. The fluctuation in the recording mark length due to mutual heat disturbance is not reduced.

So far, as a countermeasure for the component of ge mutual interference between the codes on the part of the Playback in the field of communication and magneti recording is generally a linear equalizer such as a transverse filter or the like turns. Since with such a linear equalizer the Fre quenzband of the signal reproduction system is narrow the edges of the playback signal pulse broadened, so that there is linear interference between the codes that are on occurs and with the wave near the pulse over laps, is reduced.

However, the influence of heat diffusion appears mainly as a time deviation of the wave at Reproduction. Such an influence represents a non-linear one Interference component between the codes that are not simply as a linear overlap of the fundamental wave according to the Record information can be displayed. Therefore cannot do such an edge position fluctuation component be eliminated by a linear equalizer. It is  very difficult indeed on the playback side, one to master such interference components in real time.

Even if the conventional method is the fluctuation of the Recording characteristics based on the Ursa above Chen can control the fluctuation of the record length due to the influence of the mutual heat disturbance not reduced at all who which means that the fluctuation of the record mark length due to the influence of the counter side heat disturbance there is a setting error is and that the conventional method is the fluctuation of the Not mastering recording characteristics at all can. In particular, the marking lengths are up drawing in magneto-optical recording, the one Use a recording medium with high thermal conductivity det, the fluctuation components large. If for such Fluctuation components a corresponding tolerance ge will not be able to prevent the on high damage suffered.

As a further influence by the heat it can be mentioned that for the recording of high density information using the magneto-optical recording medium um the Pitrand recording is used, in which the Information on both edges of an elliptical domain is recorded, when the recording is in Form of the conventional technique mentioned above is, because of the fact that the medium of magnetoopti plate has a good thermal conductivity, on in lower edge of the plate with lower linear speed the position of the information domain next is supposed to be moved because it is moved through the warmth of just in front of the information domain  drawn impulse is influenced. Consequently, the Information cannot be reproduced exactly.

US 4,516,235 and US 4,949,311 show further opti cal recording systems according to the prior art.

US 4,488,277 describes a control system for a front direction for optical recording of data. According to this Printouts will appear shortly after the data is recorded read and read the recording medium again compared a comparison circuit. The result is Compare a discrepancy between the recorded and the reread signal, an error signal is generated riert. This error signal is used to drive a module tors used which, for example, the pulse width and / or changes the intensity.

According to this document, there is for each writing process a review so that then according to the review the write signal can be changed. This can cause a Online review done.

The disadvantage of this solution is that it is relatively high circuitry effort is required because each Write signal is checked. It also follows from this review that also takes a lot of time for this review is required.

An object of the invention is an optical disk storage device and a method for recording and to create the reproduction of optical information which realizes improved control of the recording ren.  

To the super-dense optical recording in the magnetoop Realizing the record will be a heat flow controlled, the information must be at a desired Position accurately recorded with a desired size will. Such a project arises because the magnetoop table plate is very sensitive to the temperature. However, since the optical recording in general by the thermal recording is accomplished, the above projects taking into account all types of optical recording such as optical recording of the phase change type, the record of once writable type and the like with which the user in addition to magnetic recording information can draw, be solved.  

One of the items for realizing the super high The density of the magneto-optical recording is thereby opposed ben that the magnetic domains formed the Auf drawing each other thermally and by means of electrical Signals interfere because of the interval between the tracks and the interval between the magnetic domains of the up drawing are narrow. Therefore, the super high density of the to realize magneto-optical recording Size of the magnetic domains can be precisely controlled.  

As factors related to the size of the magneti formed exert influence, a reverse training temperature, fluctuations in the recording dien, fluctuations in laser power and the like seen. When recording or deleting such fluctuation factors detected, a return coupling is performed appropriately and the recording or deletion is made. In this way, the Recording density can be increased without the ge formed magnetic domains interfere with each other.

In general, magneto-optical recording the data recording area on a disk in radia direction and in the direction of the track into several zones Splits. An area is required for each zone with which for recording control recording required information is obtained. By running at least the recording / playback in such Range, the recording conditions are determined.

If the user information is recorded, it will recorded so that the densities of the data match each other which are balanced in any of the zones be recorded by dividing the data record area on one plate into several zones in radia direction and in the direction of the track. In egg The recording method used is the cheapest most to carry out a so-called Pitrand recording, where the recording by storing information in the peripheral areas of the recording domain is ligt.

To receive data necessary for the execution of the On drawing control are necessary, a procedure considered, in which a predetermined pattern in advance in  a magneto-optical disk drive direction is saved, the record tion / reproduction based on such benen pattern is executed. With regard to a Be sufficient for execution of the recording / playback It is desirable for testing purposes with an optical disk worth the data recording area on a disk in the radial direction and in the track direction in several zones is divided, with a track in at least one second tor or the entire circumferential area of a track in each Zone used as a test track to the different Data for the execution of the recording control too receive.

For a process for obtaining information on Controlling the record is sufficient, at least to get some kind of information from one of the magnetic width and the magnetic length of the structure th magnetic domain of the record and the Inter vall between the magnetic domains group is selected. Based on this information, who the user data by controlling the laser power the recording, the width of the recording pulse or the waveform of the recording pulse net.

With regard to the interval for the acquisition of the data for recording control, it is sufficient that at least at the time the drive is activated for the magneto-optical disk and at the time of on pushing the disk the data will be obtained exactly while in cases different from the above cases control information is less accurate than in the above Cases is obtained. The reason for this is that the information obtained here mainly consists of  the information regarding the change in the environment temperature is formed. In the information above contains the information that is obtained when the disk is a is pushed, in addition to the information mentioned also a fluctuation in the sensitivity of the plate. As a result, the compatibility of the medium can be guaranteed be steady.

The reason why the test track ver for extraction various data for executing the recording control tion for each zone in at least one sector of a track or provided in the entire circumferential area of a track is that the influences are removed are supposed to be exercised on those recording operations be because the recording conditions because of the Fluctuations between the plates fluctuate or because of that Heat flow fluctuates from one zone to the next when recording or erasing at constant speed running, or the like. The test track can be sent to an any position in a zone can be provided, so as long as the typical range in terms of character each zone. In terms of Efficiency becomes the beginning or the end intersected each zone or the central section of the Zo ne particularly preferred.

The data recording area of a disk is in radia direction and in the direction of the track into several zones shares, being in at least one sector or all The circumferential area of a track provides a track as a test track hen is, in which various data are collected to the Execute recording control. By executing the Recording / deletion for test purposes in the test track can a change in the shape of the magnetic do man of recording caused by a change in the environment  training conditions, a fluctuation between the records media and the like is caused, detected who the. Therefore, by running the recording on based on such information the magnetic Domain of the record always with the same form and the same size. By using Ver The invention can be a magnetic microdomain of the record are formed without interference to be influenced, so that a stable record can be performed. Thus a super-dense magnetic-optical recording realized will.

To match between the recording medium and the To improve recording device is at a predetermined position of the recording medium in advance performed a trial write operation, which is done by playback signal obtained from the trial write operation is compared with experimental writing data. If a good one Result has been obtained using the ordinary Recording operation started.

On the other hand, the input data bit train of Ver search write data and the normal information in the Code train of the recording device translated. It will a data train generates the code train on the record medium. It becomes a laser light source actuated, a recording on the recording medium area is formed, whereby the exact record is executed. Because the trial write process the Agreement between the recording medium and the Recording device improved, the operation carried out such that the recording mark with the important conditions regarding the data to be recorded Record marks beforehand to a predetermined Po  sition is written on the recording medium, be before the normal information is recorded to a Fluctuation in recording sensitivity of the record medium or the like due to fluctuation the film thickness or the like of the recording medium in connection with an exchange of the record me diums, a fluctuation in the ambient temperature or a Change the characteristics of the recording device detection. Furthermore, the playback signal that derived from the recorded test writing data is compared with the experimental writing data. To a gu To achieve the best result, a light intensity of wave to be recorded or the energy changed, causing the correspondence between the recording medium and the recording device is improved. Since the op maximum recording conditions for the record me dium can always be preserved, so the error sticky operation of recording the information together hang with the above-mentioned fluctuation of the recording sensitivity eliminated, so that the recording and playback performed with high reliability that can.

The recording and playback are right after the recording of normal information or in a certain period, the input data Bit train and the output bit train compared will. If a faulty operation occurs, you can by performing the experimental write opera mentioned above tion recording and playback with high confidence be carried out carelessly.

In addition to the trial write operation that follows immediately after the recording of normal information or in a certain period is run as little as possible  to shorten, the recording pulse train according to the Recording mark and the recording auxiliary pulse generated. There will be two light intensities or two energies level for the recording pulse train and the recording Auxiliary pulse used, the temperature of the on drawing medium using the above two Light intensities or energy levels almost on a front given value is set, whereby the length and the Width of the recording mark can be controlled.

To continue the accurate assessment of the record can be carried out by the test writing process, is in a state where the improvement in ampli tude, the frequency characteristics or the like of Playback signals are not made, an examination to determine whether the recording condition are good.

To solve the above further task, the up drawing pulse train and the recording auxiliary pulses ge according to the record mark of the input data bit of the test writing data and the normal information generated, the information on the recording medium order using the two light intensities or the two energy levels for the recording pulse train or the auxiliary recording pulse is recorded.

To solve the other tasks above, in one Recording medium on which the information was overwritten ben can be included in the recording performance and the Extinguishing power introduced light intensities of the up drawing pulse train and the recording auxiliary pulses modulated.  

To solve the other tasks above, the One data data bit train directly after the normal information reproduced its recording, the input Da ver bit train and the output data bit train be compared.

At a predetermined position on the recording medium a trial write operation is performed in advance. The playback signal generated by the trial write corridor is obtained with the test writing data compared. Then with the normal recording Information started when received a good result has been. In this case, the input data bit train of the test writing data and the normal information transferred to the code train of the recording device, a data train for recording the code also becomes available ges generated on the recording medium. In this case are in a recording wave for the formation of a Recording area on the recording medium Operate the laser light source or the light intensities the energy level for the recording pulse train and the Auxiliary recording pulses according to the recording mark controlled.

In a facility where the information is in a Form is recorded and reproduced on a disk-like recording medium by formation optical concentric traces can be distinguished, the track on the plate is divided into zones that are made up of If there are several tracks, the information is recorded in this way records that the linear recording densities in the Zones are aligned, and becomes linear Recording density in the zone on the inner groove of the Plate set lower than the linear density in the zone on the outer groove.  

The linear density can be on the side of the inner groove be reduced, even if a counter occurs sided heat disturbance read the information exactly who that can. On the other hand, since the share of storage capacity the track on the side of the inner groove opposite the those that are stored on the entire disk can, is not very large, the high density itself with a decrease in the linear density on the part of the inner groove can be realized efficiently without the Ka to significantly reduce the capacity per plate.

According to the invention, the variation in the edge position the record mark due to the mutual Heat disturbance set by the front or the back side for each border corresponding to a comm combination of several before the relevant recording pulse located recording pulses in time is moved. The recording is done by the laser by the set recording pulse signal leads, with a predetermined recording signal each recorded after a predetermined time interval and is played. The light beam intensity at the Record and a fluctuation in the ambient temperature are from the result of the record and the re grasped. According to the detection result, the Beam intensity when recording and an on Amount changed at every margin position. By virtue of that becomes an information record with high accuracy without fluctuation in the recording mark length under all recording conditions. The more precise Edge position control of the recording mark for the high density recording by the marking lengths record can be realized.  

The variation in the edge position of the recording mark tion due to mutual heat disturbance is switched on represents by the front side or the back side of each edge according to a combination of several recording pulses directly before the recording marker is postponed. The record voltage is set by the laser according to the Record pulse signal executed so that a swan the recording mark lengths in the case where which the recording pattern column due to the influence the mutual heat disturbance fluctuate, caught can be.

On the other hand, according to the fact that the linear recording speed depending on Recording radius changes, several types of settings Support tables according to the linear record speed provided. By using the A manipulated amount tables according to the linear speed when recording, the recording pulse can each the position of the recording medium will.

When the operation of the facility is started and if the recording medium after a given The same time interval is exchanged, the up drawing and playback using a pre given recording signal executed. A Tastver Ratio between the record mark of the how the corresponding pulse length and the gap length different from that of the recording mark which section corresponds is recorded. The beam of light intensity when recording and a deviation from a set value of the temperature of the recording medium diums are taken from the duty cycle information.  

According to the result of the removal, the light beam is turned on intensity when recording changed when the light beam intensity when recording the set value deviates. When the temperature of the recording medium deviates from the set value, the light beam intensity activity during recording - as long as the recording impulse by changing the content of the setting table or the light beam intensity when recording can be put. Even if the recording conditions can change with time, the recording voltage pulse can be set precisely.

Through the marking length record, an accurate right edge position control of the recording mark in the high-density recording are carried out as above has been mentioned.

As mentioned above, the present invention works Procedure for the stable formation (recording) of a magnetic microdomain without mutual thermal interference or the like in connection with the realization ner high density of magneto-optical recording. As a method for the above purpose, 1) is a method for the waveform of the recording pulse, 2) a ver drive for recording on the disk and 3) Procedure in which the test record is carried out and the record control information using the result of the test record is obtained been beaten. Regarding a magneto-optical Disk storage device can increase the recording capacity using at least one of the above methods increase. By using a combination of Multiple methods can record with even higher density.  

On the basis of the above investigations, an optical disk storage device is provided in accordance with the present invention, which is typically shown in FIG. 1 and which comprises: a light source 8 with which a light beam is directed onto an optical disk 1 ; an encoder 4 with which an information signal to be recorded is converted into a code train; a light source driver 7 which modulates the light beam according to the code train, which directs the light beam as a light pulse train onto the optical disk and which records the code train as a recording mark at least either by its heating function or by mutual heat disturbance; a detector 9 for photoelectric converting the light from the optical disk, thereby obtaining an electrical signal wave; a wave processing device ( 7 ) for processing an electrical signal wave; a pulse shaping device that determines a signal from the wave processing device as a pulse signal; a discriminator 15 which detects the code train recorded on the optical disk from the pulse signal; and a decoder 17 which decodes the code train from the discriminator into the information signal, the optical disk storage device being characterized in that it is provided with a test writing device 3 for modulating the light beam by means of a special test signal and for forming a test pattern on the optical plate, a device 16 for the reproduction of the test pattern and for comparison with a test signal and a control device 6 for controlling the modulation of the light beam on the basis of the comparison result and that the control device has at least one power level, one pulse width and one Controls the pulse interval of the pulses building up the light pulse train.

The control of the power level can be done through the ready position of the control device for controlling the mo dulation of the light beam can be realized by the Pulse width or the pulse interval from given Values is selected.

The comparison result represents at least one variable, that from the width, the length and the marking interval vall of the recording mark is selected.

It is desirable to record the test pattern from the rewriter 3 after it has been encoded by the encoder 4 in a manner similar to the data.

It is even more desirable to provide a changeover switch 12 for the delivery of the electrical signal wave to the pulse shaping device 13 without passage through the shaft processing device 11 and to evaluate the replay signal of the test pattern without passage through the shaft processing device.

The light pulse train of a recording mark forming unit is, for example, by a heat im pulse and a subsequent pulse train, whose temporal width differs from that of the heat pulse differs. Control becomes simple as long as the subsequent pulse train is a pulse train with little at least either the latitude or the time interval vall of the impulses are the same.

According to a preferred embodiment of the present invention, the light pulse train of a unit which forms one of the recording marks has pulses with a power level which is equal to or greater than P _w .

The light pulse train that does not form recording marks has a power level that is equal to or less than P _as . At least either the front side or the rear side of the light pulse train constituting the recording mark has an area with a power level equal to or less than _Pr .

However, the following relationships apply:

P _w = <P _as <P _r

Furthermore, the light pulse train can be one of the recordings unit that forms the markings for marking be that it has pulses with two or more power levels owns. The light pulse train of a unit that is one of the Forming recording marks can also be constructed in this way be that the power level of the head pulse from Power level of the subsequent pulses differs.

The controller controls the number of pulses of the light pulse train of a unit forming one of the recording marks, or changes at least one of P _w , P _as and P _r .

The control device can at least on the basis one of the combinations of the temperature of the optical Disk, the linear recording speed of the op table plate and the information to be recorded on the tion signal based recording mark also the edge position of the Im forming the light pulse train control pulse. It is also possible to have a table for the storage of information for the control of the Form flank position.  

The optical disk is divided into several zones, de ren recording conditions, for example, in ra Distinguish the direction, it being desirable is to provide an area in each zone where the Test sample is recorded.

The optical disk is in the radial direction in several Zones divided, it is also desirable that they are so is constructed in the same zone that the linear on drawing density is the same and that the linear record density of the innermost groove of the optical disk mi is nimal. To compensate for the linear recording density Chen, the record is preferably used of the light pulse train, so that in each zone or little according to the radial position on the plate at least either the pulse width or the pulse interval be changed.

At least either the pulse width or the pulse interval of the pulses building up the light pulse train control can suitably ver a recording clock be applied and a value set by one integer multiples larger than the width of the detection solution window that is created by the recording clock det.

With regard to the light source driver device 7 , a plurality of unit driver circuits, each having a switching device and a current source which is connected in series with the switching device, are connected in parallel, a constant current source is connected in series with each unit driver circuit, a light source 8 is connected to the constant current source in Series and connected in parallel with the unit driver circuit, the current source is constructed by a plurality of unit driver circuits so that it supplies currents with different values, and the switching device is actuated by a control signal based on the code train, whereby a current value for driving the light source 8 is controlled. At least one of the current sources of the unit driver circuit can change the current and control the light pulse.

A switching element is preferably used as the switching device of the npn type used.

According to the invention, a method for optical opening drawing and reproduction of information created at an information signal to be recorded into a Code train is converted to a beam of light accordingly the code train is modulated into a light pulse that Light pulse train directed onto a recording medium the code train as a record mark at least either by the heat function or the mutual Thermal disturbance of the light pulse train is recorded that Light from the recording medium is photoelectrically converted to get an electrical signal wave that electrical signal wave of a waveform processing un the signal from the waveform processing device is converted into the pulse signal, the train of code recorded on the recording medium is detected from the pulse signal and the detected code train is decoded into the information signal, the ver drive for optical recording and playback of In formation is characterized in that the light beam is modulated by a special test signal in order to to form a test pattern on the recording medium that reproduced the test sample and with a test signal is compared and that at least either the Lei power level, the pulse width and a pulse interval of  the light pulse train forming pulses based on the Comparison result is controlled.

It is desirable that the test pattern match the code with the greatest length and the code with the smallest length.

In the following, embodiments of the invention are described of schematic drawings exemplified in more detail.

Fig. 1 is a block diagram of the device for explaining an embodiment of the present invention;

Fig. 2 is a flow chart for explaining the operation of the embodiment;

Fig. 3 (a), 3 (b) and 3 (c) are explanatory theoretical Dar positions of the relationship between the Aufzeichnungsverfah ren and the recorded recording marks according to the embodiment of the invention;

FIG. 4 (a), 4 (b) and 4 (c) are explanatory theoretical Dar positions of the relationship between the Aufzeichnungsverfah ren and the recorded recording marks according to another embodiment of the invention;

Fig. 5 is an explanatory view of the recording pattern of the trial write of the invention;

Fig. 6 is a block diagram of the control signal detection circuit for the trial write of the invention;

Fig. 7 is an explanatory diagram showing the relationship between the heating time constant and the temperature error after the heat is turned off;

Fig. 8 is a diagram for explaining an embodiment of a recording wave;

Fig. 9 is a diagram for explaining another embodiment of the recording wave;

Fig. 10 is an illustration showing a recording signal wave;

Fig. 11 is an illustration showing a recording signal wave;

Fig. 12 is a schematic diagram showing a playback signal wave and a shape of a magnetic domain of recording;

Fig. 13 is an illustration showing the dependency of a pattern on edge shift;

Fig. 14 is an illustration showing a recording signal wave;

Fig. 15 is an illustration showing a recording signal wave;

Fig. 16 is a schematic diagram showing a playback signal wave and a shape of a magnetic domain of recording;

Fig. 17 is a diagram showing a dependency of the pattern on an edge shift;

Fig. 18 (a) and 18 (b) are diagrams showing the voltage signal waves Aufzeich;

Fig. 19 (a), 19 (b), 19 (c) and 19 (d) are illustrations for explaining a circuit embodiment of a laser driver;

Fig. 20 is a flowchart for a procedure of the trial write operation;

Fig. 21 is a schematic diagram showing a cross sectional structure of a magneto-optical disk;

Fig. 22 is a diagram showing a shape of a recording pulse wave;

Fig. 23 is a block diagram showing a construction of an embodiment;

Fig. 24 is a diagram showing a state in which the edge position is shifted due to the mutual heat disturbance;

Fig. 25 is an illustration for explaining a state in which each edge position of a recording signal is set using information of the margin shift amount and an influence of margin shift is suppressed;

Fig. 26 is a diagram showing an example of a recording signal pattern for the measurement of recording conditions;

Fig. 27 is a diagram for explaining a device for hiding and detecting a light beam intensity change in recording and a temperature change of a recording medium based on the result of the measurement;

Fig. 28 is a flowchart in the recording condition judgment mode;

Fig. 29 is a diagram showing an example of a construction of an edge interval measuring circuit;

Fig. 30 is a diagram for explaining the operation of the edge interval measuring circuit;

Fig. 31 is a diagram showing an example of a structure of the recording condition judging circuit;

Fig. 32 is a diagram showing an example of construction of an edge position setting circuit and an edge position setting table;

Fig. 33 is a diagram showing an example of construction of a circuit for switching edge position setting tables;

Fig. 34 is a graph showing the relationship between the radial recording position and the linear density;

Fig. 35 is a graph showing the relationship between the recording radius and the capacity share;

Fig. 36 is a graph showing the relationship between the recording radius and the shortest domain length;

Fig. 37 is a waveform diagram of a test pattern;

Fig. 38 is a diagram showing a shape of a magnetic domain of the record;

Fig. 39 is a plan view of an optical disk of the present invention; and

Fig. 40 is a waveform diagram showing the minimum change length.

Embodiment 1

Fig. 1 shows an optical disk storage device accelerator as an embodiment of a structure of a device of the present invention. The device is constructed from: a recording medium 1 . For storing information; an optical head 2 for performing the recording and playback; and a processing system for converting a reproduction signal derived from the optical head 2 into information. The recording medium 1 is rotated by a motor 109 and is composed of a recording film 101 and a substrate 102 which supports it.

The optical head 2 contains an optical system for focusing the light emitted by a laser 8 on the recording medium 1 . When information is recorded, an input data bit train (information) is supplied to an encoder 4, a record code train generated by the encoder 4 is transmitted to a recording wave generator 5 , a recording wave obtained from the recording wave generator 5 becomes , delivered to an APC 6 and the light with the intensity corresponding to the recording code train is emitted by the laser 8 .

When information is reproduced, the light reflected from the recording medium 1 is transmitted to a photodetector 9 by means of an optical system and converted into the electrical signal. The electrical signal is supplied to a reproduction amplifier 10 and supplied to a wave processing circuit 11 such as a wave equalizer or the like and to an input switching unit 12 . According to a trial write command signal, the input switching unit 12 supplies a reproduction signal either from the reproduction amplifier 10 or from the wave equalizer 11 to a shaft lenformer 13 . The playback signal is converted into a pulse signal which indicates the presence or absence of the signal. The pulse signal is transmitted to a discriminator 15 and to a PLL 14 . A synchronization signal (signal synchronized with the basic period of the pulse signal) output from the PLL 14 is supplied to the discriminator 15 . The discriminator 15 generates a detection code train from the pulse signal and the synchronization signal. A data bit train (information) is generated by a decoder 17 . The detection code train of the discriminator 15 is sent to a comparison discriminator 16 .

The trial write operation will now be described. Trial write data from a trial write unit 3 , which is put into operation by the trial write command, are supplied to the encoder 4 and converted into a record code train. The record code train of the trial write data is transferred via a path similar to that of the record information and recorded on the recording medium 1. When evaluating the test write data, the input switch 12 , which is put into operation by the test write process command signal, is switched so that the output of the reproduction amplifier 10 is transmitted to the former 13 . The record code train from the encoder 4 is compared with the playback code train from the discriminator 15 , generating a control signal to control the APC 6 to control a laser driver 7 to drive the laser 8 to thereby distinguish the difference to eliminate the playback code trains and the recording code trains. As a result of such control, after the difference between the playback code trains and the recording code trains is reduced to a certain level and is within an allowable range, a trial write design is output so that the trial write is finished.

After the trial write end signal is output, the input switching switch 12 is switched so that the output of the wave equalizer 11 is transferred to the former 13 , thereby starting the normal recording and reproducing operation. Also, after the normal recording operation is started, a check is made to see whether or not the difference between the playback code trains and the recording code train is within an allowable range. If such a difference is not allowed, the previous trial write operation is started. After the trial write end signal is generated, the normal recording operation continues like that. In the case of checking the difference between the playback code trains and the recording code train by the comparison discriminator 16 , the difference can be detected more precisely if the procedure is followed such that the output of the input changeover switch 12 allows the signal of the playback amplifier 10 to be generated. In the above operation, a similar operation can be performed even if the input switch switch 12 is not used. However, in order to accurately detect the difference between the playback code trains and the recording code train by the comparison discriminator 16 , it is better to use the signal that does not pass through the wave equalizer 11 .

An example of the operation of the device of the present invention will now be described using FIG. 2. By turning on a power source or the like of the device, the device is put into operation ( 2021 ). First, a check is made to see if the recording medium has been inserted in the device or not ( 2022 ). If there is no recording medium, the device is placed in a standby mode. When the recording medium is set in the device ( 2024 ), the trial write operation is performed to check the match between the inserted recording medium and the device ( 2025 , 2023 ). For the experimental writing, a recording power, a recording pulse or the like is controlled so that a fluctuation in the recording mark due to fluctuating recording sensitivity of the recording medium due to a film thickness fluctuation of the recording medium or due to an ambient temperature fluctuation is reduced as much as possible, the recording signal and comparing and judging the playback signal, the difference between the recording signal and the playback signal is restricted to an area in which the device operates normally, and the trial write end signal is output ( 2028 ), thereby causing normal operation (recording / reproduction of informa tion) of the facility is started ( 2029 ). The recording signal and the playback signal are compared and judged ( 2026 ). If a difference between the recording signal and the reproduction signal is large, the laser power is controlled ( 2027 ). The trial write operation is carried out again until the device operates normally. Even if the recording medium is replaced ( 2024 ), the above trial write operation is carried out. Furthermore, a highly accurate recording mark can always be recorded even when the device is working normally by comparing the recording signal with the playback signal.

Fig. 3 explains the relationship between an embodiment of a recording method of recording on the recording medium of the invention and the recorded recording mark. Fig. 3 (a) shows a recording pulse for controlling a laser power. An output of the encoder 4 , which has been described in FIG. 1, forms a recording code train 20 . The record code train 20 corresponds to a record mark that is recorded on the medium. In a pulse section of the recording code train 20 , a recording pulse train 21 is generated by the recording wave generator 5 . For example, as shown in Fig. 40, for the recording pulse train 21 , a length of the leading pulse is different from the lengths of the second and subsequent pulses. The pulse lengths of the second and subsequent pulse trains are set so that at least one pulse of the minimum change length (minimum change in the length of the optical pulse when the markings are formed with several lengths) corresponds to the recording mark. Further, the recording pulse train 21 is formed by a recording pulse train so that it is possible to neglect an influence on a portion near the last end position of the pulse of the recording mark by another pulse or by a recording pulse train so as to be almost negligible a predetermined amount of heat flows in. In a gap area (remaining period section, which is different from the section Impulsab) of the recording code train 20 , a recording auxiliary pulse 22 a is generated. On the auxiliary drawing pulse 22 a is set so that the heat from the last rear position of the recording pulse train does not affect the temperature at the leading position of the next recording pulse train by providing a gap area in which the laser power for a certain period of time the position in the vicinity of the rear position of the recording code train 20 is reduced.

Fig. 3 (b) shows a change in the laser power according to the recording code train in the case where the laser 1 is operated using the recording pulse train 21 and the auxiliary recording pulse 22 a, with an abscissa axis indicating the time and an ordinate axis indicating the laser power. The lowest level of laser power indicates a playback power P _r during playback. The highest level of laser power indicates a recording power P _{w of} the recording pulse train 21 . The intermediate level indicates a recording power P _{as of} the auxiliary recording pulse 22 a. As shown in Fig. 3 (c) ge, the length and the width of the recording mark 23 on the recording medium are controlled with high accuracy. Since the temperature on the recording medium is kept constant, the width of the recording mark 23 is controlled within a predetermined range so that the amplitude of a reproduction signal 24 becomes constant. A playback code train 25 is generated by detecting the center of the playback signal 24 or by judgment using a threshold of a certain level.

As an example of the operation of the comparative discriminator 16 , the lengths of the pulse portions of the record code train 20 in Fig. 3 (a) and the playback code train 25 in Fig. 3 (c) and the intervals of the leading positions or the rear positions of the pulses or the like compared and evaluated. For example, in the case where the laser power is too large, the pulse length of the playback code train 25 is longer than the pulse length of the recording code train 20 . On the other hand, if the recording power is low, the pulse length of the playback code train 25 is smaller than the pulse length of the recording code train 20 .

A detection method has already been described in detail in "Digital Signal Recording and Reproducing Apparatus" of JP-A-4-61028, filed by two of the present inventors. Here, a new method is also proposed in which the dimension of a detection circuit is not so large. For the recording pattern used as the test pattern, for example, the shortest record mark and the longest record mark, which are determined by a record modulation code as shown in Fig. 5, are alternately used. When using 1-7 modulation as the modulation method, lengths corresponding to 1.33T and 5.33T are preferred, with one bit period taking the value T. Assuming that a bit density is set to 0.56 µm / bit and a wavelength of the laser used is set to 780 nm and NA of the lens is set to 0.55, the length of the shortest mark is 0, 75 µm. The subsequent playback waves contain no harmonic components and are only formed by the fundamental waves with regard to the resolution of the optical system. In general, the playback wave is affected by both the length and the width of the mark, because the shortest mark is smaller than the diameter of the replay light spot.

On the other hand, the signal amplitude of the reproduction wave of the longest mark is determined only by the influence of the width. The interval between the leading edge and the trailing edge of the signal corresponds to the length of the marking. When using the recording wave according to the present invention as shown in Fig. 3, the width of the longest recording mark can always be made equal to the width of the shortest recording mark. Therefore, a difference between the reproduction waves of the shortest mark and the longest mark can be seen as the difference between the lengths.

If as a binary conversion method a method of the di right sharing is used, a so-called Marking length record where the information is stored on both edges of the marker and the information is converted into data pulses , it is necessary to be precise about the division level voices. It is well known that when the latitudes the markings are the same and the shortest markie length longer than half the light spot diameter sers, such a division level preferably to the half the amplitude level of the longest markie length is set. This means that if the Markie  length longer than half the light spot diameter sers, the playback signal from the marker edge does not affect the edge of the adjacent marker as long as the light spot is on the marking edge finds. Therefore, the intersection corresponds to the re Gabewelle at a time when the division with the half the amplitude value by the longest marker length is determined, is made the edge of the mar marking.

For the above reasons, it is for capturing the Mar length from the tentatively written signal wave first required a reference division level to put. For this purpose, the playback wave of the repeating pattern of the longest mark of the refe received limit level. As such a procedure is a procedure ren known, for the extraction of half the value the amplitude of the longest marker signals that the upper envelope and lower envelope of playback Specify signals from the mark by an envelope Detection circuit are generated and an average the same is obtained and set as a reference level (JP-A-59-203244).

Another method of setting the division level is now shown. The repeating pattern of the longest mark is recorded so that the mark length is equal to the length of the mark gap. However, even if the recording conditions deviate and a balance between the mark length and the mark gap length deviates somewhat, in the case of the repetitive pattern of the longest mark, the mean value is almost equal to the value obtained with the previous method. A circuit as shown in Fig. 6 is used as a method for obtaining such a value. The reproduction wave is converted into a binary form based on the variable division level by a binary conversion circuit 601 , thereby forming a pulse. In a charge / discharge circuit 602 , an integration circuit is operated by the leading edge of the pulse so that the charging operation is carried out. The loads are unloaded from the rear flank. A sample / hold comparator 603 samples and holds a value of an integrator at the forefront of the next pulse. A division control section 604 performs feedback control for the binary conversion circuit 601 so as to change the division level so that the sampled and held value is zero. At a time when the division level is set, the division level is converted from analog to digital by means of an A / D converter 605 . The digital signal is sent to a memory circuit 606 and stored there. The above operation is carried out in a similar manner for the shortest mark and the longest mark, the values obtained being set to V₁ and V₂, respectively. The recording conditions are changed so that a difference between them is 0.

Embodiment 2

Fig. 4 shows another embodiment of the recording method of recording on a recording medium according to the present invention. As shown in FIG. 1, as for the recording code train 20 , the recording pulse train 21 is generated in the pulse portion of the recording code train 20 by the recording wave generator 5 . The recording pulse train 21 is constructed from a recording pulse train such that the length of the leading pulse and the lengths of the second and subsequent pulses are different from each other, the pulse lengths of the second and subsequent pulse trains being set so that at least one pulse of the corresponds to the minimum length of change of the recording mark and the influence by the heat from a further pulse train on a portion near the last rear position of a recording pulse can be neglected, so that a given amount of heat flows in.

In Fig. 4 (a), a recording auxiliary pulse 22 b is generated in a gap portion (remaining period portion which is different from the pulse portion and corresponds to the interval of the recording mark) of the recording code train 20 . As for the recording auxiliary pulse 22 b, by providing a portion such that the laser power is reduced in a period before the front position of the recording code train 20 and for a predetermined period of time from the rear position of the recording code train 20 , the heat of the last rear position of the recording pulse train hardly the temperature at the heat-conducting position of the next record pulse train.

Fig. 4 (b) shows a change of the laser power in accordance with the Aufzeichnungscodezug in the case in which the laser is operated I un ter using the recording pulse train 21 and the recording auxiliary pulse 22 b, where an axis of abscissa indicates time and an ordinate axis shows laser power. The lowest level of the laser power indicates the playback power P _r during playback. The high level during recording indicates the recording power P _{w of} the recording pulse train 21 . The low level during recording indicates the recording power P _{as of} the auxiliary recording pulse 22 a. The length and the width of the recording mark 23 are controlled on the recording medium with high accuracy using a recording wave as shown in the graph. On the other hand, since the temperature on the recording medium is kept constant, the change in the width of the recording mark 23 is controlled within a predetermined range so that the amplitude of the recording portion of the reproduced signal 24 is almost constant. The playback code train 25 is generated by judgment based on the center point or a certain level of the playback signal 24 .

Now consider a temperature component on the disk surface which is controlled by the above recording wave. A maximum impact temperature reached by the recording pulse is set to T _max , while a temperature rise due to the replay laser power is set to KP _r using a special coefficient K. An ambient temperature of the facility is set to T _r . The temperature rise by the recording laser power is expressed by using a special coefficient K 'by K' (P _w - P _as ). Further, a function expressing a decrease ratio of the temperature after the end of the radiation with the recording pulse for a time t is set to f (t). A function that expresses a ratio with which the temperature rises after irradiation with the auxiliary pulse is set to g (t). An origin of the time t is set to an end time point of the recording pulse. A temperature T (t) can be expressed as follows.

T _max - T _r - KP _r ) f (t) + T _r + KP _r + K (P _as - P _r ) g (t) = T (t) (Equation 1).

If it is now assumed that the detection window width is set to T _w by the 1-7 modulation, both the shortest marking length and the shortest gap are equal to 2T _w . The most serious condition in terms of the thermal balance mentioned above concerns the case where the marking gap is the shortest. Therefore, the shortest time until the beginning of the next marking section after the end of the marking gap relates to the case in which t is 2T _w . The longest time is 8T _w . For settlement such that the heat has no influence on the recording of the previous mark regardless of the pattern of the next mark, it is desirable that T (t) have a predetermined value C within a range of t from 2T _w to 8T _w . In addition, for a setting such that the widths of all the markings are the same, it is a necessary condition that, for such a predetermined value C, the highest impact temperature, which is the result of the addition of a temperature rise K′X (P _w = P _as ) is achieved by the recording pulse of the next marking, corresponds to the highest impact temperature T _max that has been reached by the previous marking. For a given value of C, a tempering is temperature necessary which is ultimately achieved by the heat _w to 8T _w is at least within a range of two T to prevent the previously continuous marking exerts on the subsequent marking an influence. Such a temperature is obtained in equation (1) as the limit of equation (2).

f (t) → 0 g (t) → 1 (equation 2).

C may be obtained as follows.

C = T _max - K ′ (P _w - P _as ) = T _r + KP _r + K (P _as - P _r ) (Equation 3).

Now it is assumed that a difference between P (t) and C is set to E (t).
E (2 _w ) = K ′ (P _w - P _as ) f (2T _w ) - (1 - f (2T _w ) - g (2T _w )) · K (P _as - P _r ) (Equation 4).

It is easily understood that the amount of change of a heat source can be considered as a quantity for determining a heat flow. Therefore, if it is assumed that a power change of the recording pulse is set to P _w 'and a power change of the recording auxiliary pulse is set to P _as ', the equation (4) can be rewritten as follows.

P _w ′ = P _w - P _as
P _as ′ = P _as - P _r (Equation 5).

Equation (4) therefore takes the following form.
E (2T _w ) = K ′ P _w ′ f (2T _w ) - (1 - f (2T _w ) - g (2T _w )) KP _as ′ (equation 6).

In the above equation, the first term on the right denotes the influence by the recording pulse of the previous mark, while the second term denotes the influence by the recording auxiliary pulse. A process for turning off the recording auxiliary pulse means that the coefficient of the second term is controlled. If the auxiliary recording pulse is not switched off, the second term is zero regardless of the time, while the influence of the recording pulse cannot in principle be eliminated. From equation 6 it is understandable that in order to eliminate the influence by the recording pulse of the previous marking E (2T _w ) there must be a temperature error such that it hardly influences the shift of the marking edge. To meet the above condition, a combination of P _w ', P _as ', f (2T _w ) and g (2T _w ) must be considered. On the other hand, a combination of P _w 'and P _as ' is determined from another point of view. The following equation (7) is obtained from the equation (3) showing the steady state relationships between the recording auxiliary pulse, the recording pulse and the ambient temperature.

T _max = T _r + KP _r + KP _as ′ + K′P _w ′ (equation 7).

As for T _max , the width of the mark is determined when the spot shape, the linear velocity and the characteristic of the thermal conductivity of the medium are determined. Furthermore, the mark length is determined when the previous recording pulse wave is set. Therefore, T _max must be pressed to a constant value in order to control the width and the length of the marking to predetermined values. That is, the right side of equation (7) must be constant. If the environmental conditions and the playback power are fixed, the sum of P _w 'and P _as ' must be constant. Factors for the determination of K are the spot shape, the linear speed and the characteristics of the thermal conductivity of the medium. Factors for the determination of K 'include this and a recording pulse wave. Since the functions f (t) and g (t) are functions which indicate the decrease and increase ratios of the temperature, it follows from equation (6) that they have only values within a range from 1 to 0 for the reduction of the error can. In view of the above fact, it is favorable that KP _as 'and K'P _w ' are almost the same, because this extends the permissible widths for f (t) and g (t). f (t) and g (t) are determined by the characteristics of the thermal conductivity of the medium. As he mentioned above, f (t) is determined by the relationship between the linear velocity and the heat transfer velocity. g (t) is determined by the heat capacity of the film and by the linear velocity. Now it is assumed that the decrease and increase ratios of the temperature are expressed by exponential functions of time and that their time constants are set to tau1 and tau2 and the auxiliary light switch-off time is set to t₀.

f (t) = exp (-t / tau1) (Equation 8)

g (t) = 1 - exp (- (t-t₀) / tau2) t t₀; g (t) = 0 t <t₀ (Equation 9).

As will be explained below, it is very convenient that the recording wave is synchronized with the recording clock to implement the circuit. Therefore, the duration t is expressed by setting the detection window width T _{w of} the 1-7 modulation to a unit value. Now it is assumed that KP _as 'is set to 80 degrees, that K'P _w ' is set to 100 degrees, that a shutdown time is set to T _w and that a temperature error of T (2T _w ) is in a range of ± 10 degrees. Then a combination of tau1 and tau2 that meets the above condition is of the type shown in FIG . These numerical values indicate conditions such that the edge shift is within 10% of T _w when T _w is 40 ns and the linear velocity is 9.4 m / s if a medium as described in JP - A-61-9034 8, and a magneto-optical recording film can be used. The square area indicates an area in which a steady state will soon be reached because a damping increase ratio is high. An area in which the heat balance is obtained by switching off corresponds to a hatched area. In order to reduce the temperature error even if each element fluctuates from four combinations, it is desirable to choose the square area as the area. In the above range, when tau1 is set to 0.4 or less, the influence by K'P _w 'is remarkably suppressed, so that the allowable ranges for the shutdown period and tau2 are increased. When the mark length recording is used as the recording method and the MCAV recording is carried out, although the absolute duration of T _{w changes} due to the radial position, by standardizing the turn-off duration and the time constant by T _w beforehand, all of the above results can be achieved will.

Embodiment 3

Another embodiment of the recording pulse will now be described. In the above embodiments in Figs. 3 (89643 00070 552 001000280000000200012000285918953200040 0002004293957 00004 89524a) through 3 (c) and 4 (a) through 4 (c), a combination of the leading is used for recording the shortest mark of 1-7 modulation Pulse with the temporal Chen width T _w and one of the subsequent recording clock pulses used. As far as the recording clock is concerned, the clock with the T _w period is generally used, so that it is expedient to use a clock in view of the circumstances of the circuit. If in reality a transfer rate is close to 4 MB / s, it is difficult to form clocks with a double period. However, when the number of power levels corresponding to the recording pulses is one and when the shortest mark is recorded using such a combination of these pulses and by a mark length by T _w every time after a recording clock pulse, the thermal characteristic of the recording medium is limited. In view of the above time constant, such a situation corresponds to the case with a relatively large value.

For a wave that is suitable even in the case of media with different heat characteristics, as shown in Fig. 8, the shortest mark is recorded by a pulse with a recording power change amount W 1 of length a. The shortest mark, which has the desired width and a length of 1.33T, can be recorded by a combination of the recording auxiliary pulse with the level of T _as and the above recording pulse. If the following marker is recorded after T _w , it is recorded as the recording power change amount W₂ using the previous recording clock. In order to set the width of the marking to a predetermined value regardless of the marking length, the highest impact temperature of each recording cycle is set to a predetermined value. In Fig. 8, a temperature is obtained at each point in time between the time t₂ and t₆. Assuming that a function that expresses an increase in heat by the pulse irradiation is set to h (t) and a function that expresses the decrease in heat by stopping the pulse is set to l (t) Increase in heat by the recording pulse at every time the relationship as shown in Fig. 9 ge. If they are replaced by P, Q and R for the sake of simplicity of explanation and the conditions for W₂ are obtained so that the temperatures at times t₂ and t₃ are equal to one another, a relationship as shown in FIG. 9 is shown.

W₂ = R (1 - P) W₁ / Q (Equation 10).

Therefore the temperatures are also for a period of time from t₄ to t₆ almost the same.

A pulse width of a is formed from the pulse width of 2T _w using a delay line or the like. By using the power levels of two recording pulses, the highest impact temperature for each pulse can be adjusted. As is easy to understand from equation (10), the above method has the disadvantage that even when it is set to a medium due to the fluctuations in the recording pulse widths a and d and the fluctuations in the recording means such as changes in the main characteristics of the Laser driver circuit and the like Q and R are changed so that the temperature fluctuates at any time and can not be corrected. However, as shown in Fig. 9, the recording clock is used unchanged, the power for recording the shortest mark and the power for the subsequent pulse are changed to W 1 and W 2, respectively, and the power W 1 is used to form the shortest mark obtained with the length of 1.33T by the recording auxiliary pulse with the P _as level and by two recording clocks. If the impact temperature is obtained during a period from the time t₁ to t₅ and W₂ is obtained from the conditions that the temperatures at t₂ and t₃ are equal to one another, applies

W₂ = (1 - PP) W₁ (equation 11).

In the above case, if the characteristics of the medium are not changed, the influence by the fluctuation of the recording pulse width and the fluctuations of the recording means such as changes in the main characteristics of the laser driver circuit and the like can be eliminated by the trial writing of the present invention because the tempera change at any time with a constant speed. That is, it is possible to make a correction by changing the recording aid pulse because a change in temperature is constant regardless of the mark length. In order to carry out a synchronization with the recording clock in FIG. 8, it is sufficient to set T _w to a. In the above case, if the width and the length are matched, it is difficult to control the width.

The relationships between the trial write operation and various types of fluctuation factors will now be described using equation (7). When the fluctuation in the ambient temperature changes from T _r1 to T _r2 , a change P _as ' of the auxiliary light is changed, whereby T _{max is} kept constant. In view of the fluctuation in the film thickness of the recording medium and the fluctuation in the recording sensitivity, the recording temperature changes. However, since a change can be considered such that T _max effectively changes from T _max1 to T _max2 , the change in P _as ' of the auxiliary light is changed, whereby control is carried out such that such an amount of change is compensated for . In the fluctuation of the recording power, although P _r and P _as ' P _w 'change, T _{max can} also be made constant by changing the change P _as ' of the auxiliary light. For this, KP _as 'must have a value that is similar to K'P _w '. The fluctuations in the recording characteristics by the recording and reproducing device correspond to the fluctuations of K and K '. In these cases, too, T _max can be made constant by changing the change P _as ' of the auxiliary light.

Embodiment 4

Another embodiment is now shown. Fig. 10 is a diagram showing a form of the recording pulse used. The recording powers of the leading and second pulses in the recording area are set to 6.5 mW at the position of the innermost groove of the disk such that the speed of the disk medium is 3000 min ^-1 and the recording powers of the third and subsequent pulses are 6 mW are set. The preheating power is set to 2.3 mW, while the pulse width and the gap interval are set to 20 ns. Such an interval is set by means of the recording clock. Although the disk medium of the embodiment has been shown with reference to the case where the leading pulse is set at high level, there is also the case where the leading pulse is set at low level according to the structure of the recording medium. The recording on the disk was carried out using the light pulse of FIG. 10. The low power portion between the recording pulses is provided immediately after the recording pulse, its period is set to 40 ns. These values are determined by the structure of the medium of the magneto-optical disk. By setting the parameters or the like through an experimental recording, compatibility between the media can be ensured.

Fig. 12 shows a schematic representation of a reproduction signal wave and a magnetic domain of the recording when the shortest mark of 1.33T after the longest mark of 5.33T is recorded using the (1,7) -RLL modulation method. The width of the magnetic domain formed is 0.7 µm, the shortest length of the magnetic domain is 0.75 µm, and the greatest length of the magnetic domain is 3.0 µm. From the illustration, it is understood that both the shortest magnetic domain and the longest magnetic domain are not affected by each other, that the width of the magnetic domain is constant regardless of the length of the pattern, and that even in the case where the three are shortest magnetic domains of 1.33T after the magnetic domain of 5.33T are formed, because of the equality of the lengths of 1.33T of each magnetic domain, these magnetic domains are not affected by the heat of the previous magnetic domain.

Fig. 13 shows the differences between the pulse widths of the recording signals when different types of patterns have been recorded based on the (1.7) modulation and the widths of the reproduction signals. In this representation, the edge shift at this time is independent of the length of the magnetic domain formed and equal to or less than 5% of the detection window width.

Even after the record, play and delete operations had been repeated 5 · 10⁷ times no changes in carrier wave level and noise gels found.

A similar effect is obtained by using the wave ir any one of the waves shown in Figs. 11 and 12 as a pulse shape different from that of Fig. 10. The pulse and gap intervals are set to 20 ns. It is convenient to set the width of the leading pulse to 7.5 mW in the case of pattern I and to 6.7 mW in the case of pattern II. However, these values are set according to the thermal structure of the medium used.

As for the plate structure, in the case of a plate having a four-layer structure including a PC substrate, SiN _x (75 nm), TbFeCoNb (25 nm), SiN _x (20 nm) and Al₉₇Ti₃ (50 nm), by oppositely setting the power of the leading pulse to a low value of 5.5 mW and by setting the powers of the second and subsequent pulses to a high value of 5.95 mW, a shift to ± 2 nm or less can be restricted.

Embodiment 5

Another embodiment is now shown. Fig. 15 is a schematic diagram showing a shape of the recording pulse used. In the case of the disk medium with a speed of 3000 min ^-1 , the recording power of the leading pulse at the first edge position of the disk is set to 6.7 mW, while the powers of the subsequent pulses are set to 6 mW. The preheating power is set to 2.3 mW, the width of the guide pulse is set to 55 ns and the widths of the subsequent pulses and the gap intervals are set to 20 ns. The recording on the disk is carried out using such pulses.

Fig. 16 shows a schematic representation of the reproduced signal wave and the magnetic domain of the recording when the shortest magnetic domain of 1.33T is recorded after the longest magnetic domain of 5.33T using the (1.7) -RLL modulation method has been. A width of the magnetic domains formed is 0.7 µm, the length of the shortest magnetic domain is 0.75 µm and the length of the longest magnetic domain is 3.0 µm. It is apparent from the illustration that the shortest magnetic domain and the longest magnetic domain do not interfere with each other, that the width of the magnetic domain is constant regardless of the length of the pattern, and that even in the case where the three shortest magneti domains of 1.33T after the magnetic domain of 5.33T have been recorded because of the equality in the lengths of each of the magnetic domains of 1.33T these are not affected by the heat from the previous magnetic domain.

Fig. 17 shows differences between the pulse widths of the recording signals and the widths of the reproduction signals when different kinds of patterns have been recorded based on the (1,7) modulation. From the illustration it follows that the edge shift at this time is equal to or less than 5% of the detection window width without depending on the length of the magnetic domain formed.

Even after the record, play and delete operations had been repeated 5 · 10⁷ times no changes in carrier wave level and noise gels are determined.

A similar effect is obtained even if a wave having any of the shapes shown in FIG. 18 is used as the pulse shape, so that there is no limitation to the pulse shape shown in FIG. 15. In the case where the magneto-optical recording medium has a structure such that it can be easily heated and cooled, in order to give both the preheating and the recording characteristics to the leading pulse, the pulse width must be longer than that of those subsequent impulses are set. It is desirable to set the pulse width to a value that is an integral multiple of the recording clock.

Fig. 19 shows a specific construction of a laser driver circuit for executing the trial write process of the present invention. For the powers P _w1 , P _w2 , P _as and P _{r of} the waves shown in Fig. 19 (a), the current sources I _w1 , I _w2 , I _as and I _{r become so} through a driver circuit shown in Fig. 19 (b) set that the laser beam has a predetermined power in terms of a current efficiency of the photoelectric conversion of the laser or on the efficiency of the optical head. Only I _as is set variably because it is controlled by the test writing process.

Each recording pulse by means of a current switch CS controls whether the individual currents are supplied to the laser. As shown in Fig. 19 (c), the current switching circuit does not use the pnp type to increase a response speed by driving the positive charge carriers, but executes the switching operation by the npn type so as to make it special Has driver circuit structure. That is, a current source I, as shown in Fig. 19 (d), is constructed so that the maximum current flows in a stationary manner and the current flowing into the laser only through the current value components of the current sources I _r , I _w1 , I _{w2 is} lowered and that CS I _{as is} present on the side of the current _switch . Therefore, the pulses P _r , P _w1 , P _w2 and P _as for the control of the current _{switch must} have polarities that are opposite to the polarities of the waves for optical recording. In the trial writing operation of the present invention, the foregoing recording pattern is recorded in one track of each sector, which indicates a data delimiter, by changing the size of the recording auxiliary pulse. Now, assuming that the diameter of the disk is 5.25 inches and the linear speed is set to about 0.56 µm / bit, the number of sectors even at the inner groove is 32 according to the MCAV recording method. For example, in the single trial write operation, a change amount of the auxiliary light is changed by five steps. First of all, it will be changed by five levels. Such a large change operation is performed when the disk is loaded for the first time or when the disk is replaced. It is then checked where the greatly changed amount is located, the detected interval containing the amount being further divided and changed by five levels.

Fig. 20 shows an experimental write procedure. In terms of the frequency of the trial write operation, the most serious condition is a period between the time the power source of the device is turned on and the time when the temperature reaches a value where the heat is in equilibrium. Although the temperature depends on the heat generation conditions of the circuit or the like, it increases by about 10 ° C in five minutes. By starting at the beginning, it is possible to carry out sufficient control even after every five minutes.

In Fig. 20, the trial write operation is performed when the optical disk is replaced, when the device power source is turned on, or at an appropriate time during device operation ( 2001 ). A region of the medium is selected ( 2002 ) in which the test write operation is carried out. As the trial writing area, for example, a special area (trial writing track area) is set in the track of the outer groove, the inner groove or the middle groove of the optical disk. A trace in the test area is deleted with respect to the case where some data for the test write or the like has already been recorded in the test area (2004). A test write test sample is then recorded on the track. As a test pattern, for example, a pattern shown in FIG. 5 or 25 is recorded by means of a recording pulse train as shown in FIGS. 3, 4, 8, 10, 11, 14, 15, 18 etc. In the embodiment, the pattern of Fig. 5 is used, the power P _{as of} the recording assist pulse is changed in each sector, and the data of a circumferential line of the track is recorded ( 2005 to 2009 ).

The recorded test sample is then reproduced ( 2010 , 2011 ) and evaluated. The evaluation is carried out by calculating a difference ΔV between the average level V₁ of the reproduction wave of the densest pattern of the test pattern and the average level V₂ of the reproduction wave of the coarsest pattern ( 2012 ). The value of ΔV is obtained in each sector ( 2012 to 2015 ). The recorded test samples are then deleted ( 2016 ). The value of P _as in the sector with minimum ΔV is set as the optimal power of the recording auxiliary pulse ( 2017 ). In the embodiment, the above operations are carried out with respect to the outer groove, the inner groove and the middle groove of the optical disk ( 2018 ). After completing these operations, the normal data recording operations will start ( 2019 ).

Embodiment 6

Fig. 21 is a schematic view showing a cross-sectional structure of used in the embodiment of th plate. As for the plate, a recording medium is formed by a sputtering method on a plastic or glass substrate with concave and convex guide grooves. The medium is formed by continuous layering of a SiN _x film with 80 nm, a TbFeCoNb film with perpendicular magnetic anisotropy with 25 nm, a SiN _x film with 20 nm and an Al₉₆Ti₄ film with 50 nm without the vacuum during interrupt the stacking processes. The reason why the layers are continuously stacked is to suppress the formation of an impurity layer such as oxygen or the like in the layer interface. The above layer structure is only shown as an example. The effect of the invention is not lost due to the layer structure. On the contrary, since a magnetic microdomain can be stably formed by the present invention, the super-dense optical recording can be realized. Although the magneto-optical plate with a 4-layer structure has been shown here, the effect of the invention is not restricted by the number of layers of the layer structure.

The operation of recording on the above disk is carried out using a wave having a pulse shape as shown in Fig.21 . The pulse width of the recording wave is synchronized with the write clock of the disk storage device. Such a synchronized pulse width has the advantage that the clock signal can be easily generated and that the low cost of the device can be achieved, it also has the feature that the accuracy of the clock is also high. The recording wave is built up by four power levels. The first level is a read level (playback level) with P _r = 1.5 mW. The second level is a support level (auxiliary level), with P _as = 2.7 mW. The third level is a first _recording level, with P _w1 = 5.1 mW. The fourth level is a second recording level, with P _w2 = 5.9 mW. The (1,7) -RLL modulation method is used as the signal modulation method, with which the recording is carried out. As for the pulse width, the bits of the shortest mark are formed by the above modulation method using the pulse width of 60 ns and the laser power of P _w1 . Then the bits of 2T are formed by P _w2 of 20 ns by means of the P _as level of 20 ns. After that, the pulses from 2.66T to 5.33T are formed by repeating the above processes. The pulse width and the laser power are variable in accordance with a structure of the plate or a material used and are determined in view of the alignment between the device and the plate. That is, there is also the case where P _w1 = P _w2 or P _w1 <P _w2 .

The magnetic domains by the above procedure recorded will be played back (under Use one of a leading edge / trailing edge reproduction process). There is a window margin 30% while a shift is equal to or less than ± 2 ns is. A random pattern is used for the measurement.

Although an SiN _x material has been used in the embodiment, at least one compound selected from silicon nitride, aluminum nitride and silicon oxide can also be used as long as an inorganic compound dielectric material that does not optically absorb is used. Further, although Al₉₆Ti₄ has been used as the metal layer for reflecting the light and for controlling the heat flow in the embodiment, it is also possible to use at least one element selected from Au, Ag, Cu, Al, Pd and Pt is. To further control thermal conductivity, it is also possible to use a film in which, in addition to the above-mentioned element other than the mother elements, at least one element in an amount ranging from 0.5 atomic% to 30 atomic%. % added, which is selected from Nb, Ti, Ta and Cr.

Embodiment 7

Now, another reference will be made to the drawings leadership form of the present invention described.  

First, the process of shifting the edge position and explains the principle of its suppression.

Fig. 23 diagrammatically shows a state in which the edge position is shifted by the mutual heat disturbance.

In Fig. 23, the time course or the spatial coordinates of the recording medium on which the light spot is moving are shown in the transverse direction. A recording signal 201 shows a temporal shift in the intensity of the light spot which is radiated onto the recording medium by modulation in accordance with the recording information. The recording mark 23 shows a form of Aufzeichnungsmarkie formed on the recording medium by the recording signal 201 tion. The reproduced signal 24 is obtained by scanning the recording mark 23 by the light spot having the light intensity of the reading level and by receiving the reflected light from the recording medium at that time by the photodetector and by photoelectrically converting the reflected light. The binary playback signal 25 is obtained as a result of the playback signal reflecting the shape of the recording mark being binary converted depending on whether the signal level is higher or lower than a predetermined level.

Fig. 23 shows the first leading edge of the recording signal 201 , the edge position of the front side of the leftmost recording mark 23 and the first leading edge position of the binary reproducing signal 25 with each other. L [i] and B [i] denote a length of each pulse interval (from the leading edge to the trailing edge) and a length of a gap interval (from the trailing edge to the leading edge) of the recording signal 201 . i denotes the serial number (the first value is 0) from the first recording pulse (binary playback pulse).

According to the Infor optical recording method mation, in which as an information recording mechanism the record mark basically through the given heat spot is formed, this becomes heat given by the light spot in the recording medium diffuses in the cooling process, so that the reverse temperature of the light spot increases. Therefore determined in the case where the size and interval of the on drawing marker are set to small values in order to record with high density, each pulse form of the recording drawing signal not only the corresponding forms of Recording mark, but also affects the for of the surrounding recording marks. On the other hand does not become the shape of each record mark only by the appropriate form of the recording pulse ses determined, but by the shape of the temporally adjacent beard recording pulse affected.

As a result, the recording mark is influenced by the temporally adjacent recording pulse and a deviation occurs between the pulse interval of the recording signal 201 and the edge position of the recording mark 23 . Thus, relative deviations e [i] and f [i] occur between each of the edge signals of the recording signal and each of the edge positions of the binary reproduction signal 25 . e [i] denotes an amount of deviation between the trailing edge of the recording signal 201 and the trailing edge of the binary reproduction signal 25 . f [i] denotes an amount of deviation between the leading edge of the recording signal 201 and the leading edge of the binary reproduction signal 25 . i denotes the serial numbers (the initial value is 0) from the leading edge or the trailing edge of the first recording pulse (binary playback pulse). f [0] is set to 0.

In this situation, the edge deviation values change sluggish e [i] and f [i] depending on the character stik of the thermal conductivity of the recording medium and its recording density. For example, in the case in which the linear recording speed is set to unge is set to 10 to 20 m / s and the recording mar label length, which indicates a recording density to half the light spot diameter for that Recording medium is set, which in general is a magneto-optical recording medium and one Structure with a magnetic TbFeCo film, a die dielectric film, a protective film and a reflectie rend film, but the edge deviations amounts expressed by the following equations where, the pulse length L [i] of the recording signal and the gap length B [i] can be used.

e [i] = Se (B [i - 1], L [i - 1]) (Equation 12)

f [i] = Sf (L [i - 1], B [i - 1]) (Equation 13)

where Se () and Sf () denote functions. That is, e [i] by the immediately preceding pulse interval L [i] and the previous gap interval B [i-1] is determined. F [i] is due to the immediately preceding gap winter vall B [i-1] and by the previous pulse interval L [i-1] determined.  

Regarding e [i] there is no problem if the influences before the pulse interval L [i-1] and after the gap tervall B is ignored, further occurs in with respect to f [i] no problem if the influences before the gap interval B [i-2] and after the pulse interval L [i] no attention is paid.

Now, using FIG. 24, a state in which the above-mentioned margin shift amount information is used, each of the margin positions of the recording signal is set, and the influence of the shift is suppressed. In Fig. 24, the transverse direction denotes the time history or the spatial coordinates on the recording medium on which the light spot is moving. A recording signal 301 denotes an electrical signal obtained by modulating the recording information. A signal 302 after completion of the setting shows a time-dependent change in the electrical signal level in which the leading and trailing positions of the recording signal 301 have been shifted in accordance with the recording pattern. The intensity of the light spot irradiated on the recording medium is modulated by the above signal.

The record mark 23 denotes the shape of the record mark formed on the recording medium by the set signal 302 . The playback signal 24 is derived by irradiating the recording mark 23 through the light spot with the light intensity of the reading level and by receiving the reflection light from the recording medium and by photoelectric conversion of the reflection light by the photodetector. The binary reproduction signal 25 denotes an electrical signal obtained as a result by converting the electrical signal representing the shape of the recording mark into binary form depending on whether its signal level is higher or lower than a predetermined level is.

The first leading edge of the recording signal 301 , the edge position of the left-most leading edge of the recording signal 23 and the first leading edge position of the binary playback signal 25 are shown one below the other. L [i] and B [i] show a length of each pulse interval (from the leading edge to the trailing edge) of the recording signal 301 and a length of a gap interval (from the trailing edge to the leading edge), respectively. E [i] and F [i] denote amounts of deviation from the edge positions of the recording signal 301 with respect to each of the trailing and leading edges of the set signal 302 . Furthermore, i denotes a sequential number (the initial value is 0) from the first recording pulse (binary playback pulse).

The principle of setting the edge position of the recording pulse is the following. For the edge position of the recording signal 301 , a deviation certainly occurs at the edge position of the recording mark 23 . However, by shifting each of the edge positions of the original recording signal beforehand and obtaining the set recording signal 302 , each edge position of the binary playback signal 25 deviates from the edge position of the recording signal 302 , but matches the edge position of the original recording signal 301 . The amount of deviation of the edge position of the recording mark 23 from the edge position of the recording signal 301 can be obtained using the above relationship equations with reference to the recording pattern. Therefore, the amount of deviation of the edge position and the amount of deviation of the binary reproduction signal for the recording signal can be obtained by using the inverse functions of the above relationship equations in such a manner that their signs are reversed and their sizes get the same amount. That is, by creating the inverse functions Cf () and Ce () such that

β = Cf (α, γ) (Equation 15)

For

γ = Sf (α, β) + β (Equation 14)

and

β = Ce (α, γ) (Equation 15)

For

γ = Se (α, β) + β (Equation 16),

E [i] and F [i] can be obtained by the following formulas can.

F [i] = B [i-1] + E [i-1] -Cf (L [i-1] + F [i-1] -E [i-1], B [i-1] + E [i-1]) (Equation 18)

E [i] = L [i] + F [i] -Ce (B [i-1] + E [i-1] -F [i], L [i] + F [i]) (Equation 19).

In equations (18) and (19) are the edge positions on-deviation amounts in the functions Ce () and Cf () contain. By sequential extraction of the deviation amounts E [0], F [1], F [2], E [2],. . . according to this Order will be z. B. in the derivation of F [i] in previous time E [i-1] and F [i-1] in equation 18 calculated. When E [i] is obtained, Equation 19  F [i] and E [i-1] calculated in the previous time. Therefore, F [i] and E [i] can be represented by equations 18 and 19 can be calculated.

Now the procedural principle of capturing a change light beam intensity during recording and a change in temperature of the recording medium, the this corresponds to, described.

Even in the case where the light beam intensity when recording or the temperature of the recording change medium also occurs between the flank posi tion of the recording signal and the edge position of the Record mark a deviation. If at for example the light beam intensity when recording If the voltage drops, the recording mark as a whole downsized. The position of the front edge of the up the drawing marker is moved to the rear side. The position of the trailing edge of the record mark tion is moved to the front.

The amount of deviation of each edge position of the up Drawing mark is for each record made markings different. So the deviation the edge position of the recording mark that is on occurs when the light beam intensity at the on drawing by the process of changing the margin position amount of each recording pattern such as changes mentioned above, to decrease, it is necessary how The functions for the edge have been mentioned above position of each light beam intensity when opening Change drawing so that the dimensioning of the Sc housing system increases. To avoid the edge position prevention by a simpler system when detecting a change in light beam intensity  a setting made during recording with of the light beam intensity when recording the original value is reset.

On the other hand, the record mark itself becomes a decrease in the temperature of the recording medium overall reduced. Even in such a case the position of the leading edge of the recording mark tion to the back, the position of the rear edge of the recording mark to the front the side moved. What a temperature fluctuation be hits, the temperature can not directly on a con constant value can be controlled as long as in the facility no temperature adjustment mechanism is provided. The Characteristic of the fluctuation of the edge position of the up Drawing mark shows in connection with the tempera door fluctuation an inclination that very close to that comes, which exists in the case where the Light beam intensity when recording in a Be rich changes in which the amount of fluctuation compared an assumed temperature is small. Therefore the light beam changes in such an area intensity when recording. At a time when the value fluctuates greatly from the set value, the function for the margin position setting at recording turned on.

To capture the changes above, in a another predetermined time interval in the determined Be record specified on the recording medium voltage signals recorded. Right after the recording of the signal, the signal is reproduced, the Ab softening amount of each edge position is detected. Out the result of the detection will be the change in light beam intensity when recording and the temperature  change the recording medium hidden and he sums up.

Fig. 25 shows an example of a recording signal pattern used in the above case. As for the recording signal 401 , a plurality of edge intervals are arranged in the range of the recording mark lengths obtained in ordinary information recording from shorter or longer edge intervals so that the pulse width is equal to the pulse interval immediately after the pulse, with a signal , which is obtained by repeating such an order process several times, is used. The reason why the signal in which such an arrangement process is repeated several times is that the accuracy of the measurement result is increased by reducing the influence of the noise component contained in the result of detection by an averaging process. An example is shown here in which the recording signal is constructed in accordance with the 2-7 RLLC (run length-limited code) and the code modulation is carried out accordingly. P _w [1], P _w [2] denote edge intervals of the recording signal pulses. G _w [1], G _w [2],. . . denote edge intervals of the recording signal column. T, which is present in a further flank interval expression of the recording signal 401 , denotes a time period per information bit.

A playback signal 402 shows the playback signal wave after the completion of the binary conversion when the record mark written by such a record signal is read out. P _r [1], P _r [2], denote edge intervals of the playback signal pulses. G _r [1], G _r [2],. . . denote edge intervals of the playback signal column.

Fig. 26 shows a means for masking and detecting a light beam intensity change in recording and a temperature change of the recording medium based on the relationship between the recording signal 401 and the reproduction signal 402 . An abscissa axis denotes the pulse interval P _w [i] of the recording signal 401 . An ordinate axis indicates a result obtained by subtracting the gap interval G _r [i] immediately after the pulse interval P _r [i] of the playback signal 402 , with a measurement point being plotted in each recording situation. If all measuring points are higher than the 0 level, such a state corresponds to the case in which the light beam intensity changes during recording in one direction to values greater than the set value or in which the temperature of the recording medium changes in the direction of higher Temperatures changes as the previously assumed value. If, on the other hand, all measuring points are below the 0 level, such a situation corresponds to the case in which the light beam intensity changes during recording in the direction of values greater than the set value or by the temperature of the recording medium changing in the direction of higher temperatures than that changes the presumed value.

If the light beam intensity when recording changes, the measuring points are on a curve of a Group of given curves. Therefore, if the Light beam intensity has changed during recording, can be done through a previous examination of a group of curves drawn through the measuring points, and by storing the information of such a group of  Curves in the facility will determine whether it is possible is a change in the light beam intensity at the Record by distinguishing whether all measuring points lie on one of these curves or Not. If not all measuring points on a curve a check is performed to determine whether the measuring points from the curve to the bottom right or deviate to the bottom left. Based on the result of the Distinction, a test is carried out to determine set whether the temperature of the recording medium ge rose or fell. According to the assessment The result is the margin position setting table for the Record changed.

An embodiment will now be described, the one position of the marginal position and the principle of assessment of the Includes recording conditions as mentioned above.

Fig. 27 is a block diagram showing a construction of such an embodiment.

In Fig. 27, the optical disc 1 is rotated at a constant win kel speed by a spindle motor 109 . A laser beam for recording and reproducing is focused on the recording film surface on the disc 1 by the optical pickup 2 through the focusing lens. The optical scanner 2 can be moved in the radial direction of the disk according to the recording position of the information.

The signal detected by the detector in the optical scanner 2 is amplified by the amplifier 10 to a desired level. Thereafter, the wave of the signal is equalized by the equalization circuit 11, thereby ensuring a resolution of the reproduction signal. Thereafter, the signal is converted by a binary conversion circuit 13 into a binary reproduction signal 277 representing a digital signal. The binary signal is separated by the PLL circuit (phase lock loop) 14 into the data signal and the clock signal, with playback data being derived by means of a demodulation circuit 17 .

The above section corresponds to a data reproduction si Signal processing system of an optical disk storage systems, which is the usual mark length record method used. In addition to the above compo the playback signal processing system the present invention, a circuit system for the Detection of a change in the light beam intensity at the recording and a change in the temperature of the Recording medium and for calculation and updating a pulse interval setting amount recording and recording performance.

The above circuit system includes an edge interval measuring circuit 270 and a recording condition judging circuit 271 . First, the binary reproduction signal 277 is transmitted via the edge interval measuring circuit 270 , with each pulse interval and each gap interval of the signal being measured. The results of the measurement are transmitted to the recording condition judging circuit 271 . A change amount of light beam intensity in the recording and a temperature change amount on the recording medium are faded out and detected, and the results are transmitted to a controller 272 .

The recording condition judging circuit operates in a recording condition judging mode which is commanded by the controller every predetermined time interval and which is different from the ordinary information recording and reproducing modes. Fig. 28 shows a flow of the recording condition judgment mode.

During the operation of the system, the control device 272 monitors a predetermined time interval in the system, the above operating mode being started after such a time interval ( 2031 ). First, at the beginning of such an operating mode, the system is placed in a busy state, thereby setting a state in which ordinary recording and reproducing operations are not accepted ( 2032 ). If there is currently a task (recording, playback) that is currently being processed by the system, the device waits for the end of such a process ( 2033 ). Then, a light spot is moved to a specific area to record and reproduce a predetermined recording signal to examine the recording conditions ( 2034 ). Such an area is defined at several positions of different radii per recording medium. After completion of the movement, the predetermined recording signal is used for the examination of the recording conditions and recorded on the recording medium. The recording mark is then reproduced ( 2035 ). At this time, the edge interval measuring circuit 270 and the recording condition judging circuit 271 operate by receiving commands from the controller. The results of the assessment ( 2036 , 2037 ) are transmitted to the control device 272 . On the controller, the light beam intensity is changed during recording ( 2037 , 2041 ), or the change operation ( 2040 ) of the pulse interval setting amount during recording is performed in accordance with the results of the judgment.

For example, in the case where the Assessment is found that the light beam line intensity when recording in the direction of the values, which are greater than the specified value has changed and that this change amount is the allowable amount has exceeded the light beam intensity when opening Drawing changed by a small amount ΔP. Similar is the result of the assessment, the light beam intensity during recording by the small amount ΔP, if it is determined that the light beam intensi act in the direction of the values that are small are less than the specified value, has changed and if the change amount exceeded the allowable amount Has.

On the other hand, based on the judgment result, when it is determined that the temperature on the recording medium has changed toward the values higher than a presumed value and when the amount of change has exceeded the allowable range, the light beam intensity at Record reduced by the small amount ΔP as long as it remains in a range in which it is possible to carry out processing by changing the light beam intensity in the recording. If the range in which processing is possible is exceeded due to the change in the light beam intensity in the recording, the pulse interval setting amount in connection with the operation of lowering the light beam intensity in the recording is changed by the small amount AP ( 2039 ). Accordingly, as the judgment result, when it is determined that the temperature on the recording medium has changed toward the values smaller than the presumed value and when the amount of change has exceeded the allowable range, the light beam intensity becomes of the recording increases by the small amount ΔP as long as it remains in a range in which it is possible to carry out processing by changing the light beam intensity in the recording. When the range in which it is possible to perform processing by changing the light beam intensity in the recording is exceeded, the pulse interval setting amount in the recording becomes small in connection with the operation of increasing the light beam intensity in the recording Amount ΔP changed ( 2039 ).

If it is determined as the result of the judgment that none Amount of change exceeds the allowable range none of the recording conditions are changed.

The operations that meet the above-mentioned judgment condition conditions are carried out. The signals in the special recording areas are deleted. Of the The system is in a busy state. The operating art returns to the normal operating mode of information recording and playback back.

The time interval for the creation of the recording area Condition assessment mode is based on the fluctuation period of the change in the light beam intensity during recording and temperature change determined the recording medium. For example what the Light beam intensity in the recording concerns, so it is necessary to set the time interval to a value in which the light beam intensity at the  Record no more than the small change width of AP changes.

Now, referring to FIG. 27, the signal recording system having the structure according to an embodiment will be described. When information is recorded, the record information is code modulated by a modulation circuit 273 so as to match the characteristics of the optical information recording system. For the code modulated recording signal, each edge position is set in an edge position setting circuit 274 and by means of edge position setting tables 275 and 276 in accordance with the information regarding the immediately preceding edge intervals. The set recording signal is delivered to the laser driver circuit 7 , the laser intensity in the optical scanner 2 is modulated in accordance with the signal and the information is recorded on the disk 1 . The contents in the edge position setting tables 275 and 276 are changed by an edge position setting table switching circuit 278 in the case where it is determined as a result of the recording condition judging mode that it is necessary to change the edge setting amount and the linear recording speed.

In Fig. 27, with respect to the optical disk 1 , the spindle motor 109 , the optical pickup 2 , the amplifier 10 , the equalization circuit 11 , the binary conversion circuit 13 , the PLL circuit 14 , the demodulation circuit 17 , the modulation circuit 273 and the laser driver 7 are sufficient to use components with constructions and functions as used in a conventional optical disk storage device, so that their detailed descriptions are omitted.

The other components are described below.

FIG. 29 is a diagram showing an example of a construction of the edge interval measuring circuit 270 in FIG. 27. The binary reproduction signal 277 , which is an output of the binary conversion circuit 13 , is supplied to a pulse signal generation circuit 701 . The pulse signal generation circuit 701 generates a pulse-like signal wave every time the polarity of the input signal changes. The output signal is supplied to the recording condition judging circuit 271 and to an A / D converter 702 as a signal indicating the timing of the polarity reversal.

On the other hand, the binary reproduction signal 277 is also supplied to an integration circuit 703 which is constructed by means of an amplifier. An integration reference signal 704 is also supplied to the integration circuit 703 , which indicates the level - (VH + VL) / 2, the "H" level of the binary reproduction signal 7 being set to VH and the "L" level being set to VL. A signal indicating a difference between the binary reproduction signal 277 and an integration reference signal is generated by the integration circuit 703 and transmitted to the A / D converter 702 .

The signal from the controller is provided to a flip-flop 709 . A signal is also supplied to the flip-flop 709 as a clock signal, which indicates the time course of the polarity reversal. An output of the flip-flop 709 is used to detect the first leading edge of the binary playback signal 277 from the start of the measurement of the edge interval and to switch an analog switch 710 for an interval measurement period and to put the integration circuit 703 into the operating state.

The A / D converter 702 uses the polarity inversion timing signal as a timing for performing the digital conversion operation and converts an output of the integration circuit 703 into a digital signal. The result of the conversion is output as a polarity inversion interval signal and sent to the recording condition judging circuit 271 . The conversion accuracy of the A / D converter 702 is set so that its output value as a pulse interval setting amount has sufficient accuracy and also has a quantization accuracy and a bit number so that it does not generate an overflow.

The operation of the edge interval measuring circuit 270 in FIG. 29 will now be described with reference to FIG. 30. The binary reproduction signal 277 is an output of the wave former 13 and is set to the "H" or "L" level in accordance with the presence or absence of the recording mark at the irradiation light spot position on the recording film surface. The binary reproduction signal 277 is transmitted through the pulse signal generating circuit 701 and becomes the signal indicating the time course of the polarity reversal to generate the pulse wave with the time course in which the polarity changes. The signal is used as a trigger signal in the A / D converter 702 .

The integration circuit 703 calculates and generates the pulse interval of the binary reproduction signal 277 .

Assuming that an input signal from the integrating circuit 703 is set to X (t), the following output signal Y (t) is generally obtained.

That is, an initial value (output signal level at a time when the edge interval measuring circuit starts operating) Y (0) of the output signal Y (t) is 0 due to the operation of the analog switch 710 . Therefore, using the pulse intervals P _r [1], P _r [2,. . . of the reproduction signal 402 in FIG. 25 and the gap intervals G _r [1], G _r [2],. . . for the output signal level V₀ of the integration circuit 703 at the time when the polarity of the binary playback signal 7 changes from "L" to "H",

V₀ = A (-P _r [1] + G _r [1] -P _r [2] + G _r [2] +... -P _r [i] + G _r [i]) (Equation 21).

The output signal level V₀ is at a time when the polarity of the binary reproduction signal 277 changes from "H" to "L"

V₀ = A (-P _r [1] + G _r [1] -P _r [2] + G _r [2] +.. -P _r [i]) (Equation 22).

"A" in the above equations denotes a constant determined by a gain of the integration circuit 703 . That is, the output signal level at this time indicates the result of integrating the pulse intervals when the "H" level is expressed by a negative value and when the "L" level is expressed by a positive value with respect to the pulse interval of the binary reproduction signal 277 is expressed.

The A / D converter 702 converts the integration signal level to the digital value at this time and supplies the result of the conversion to the recording condition judging circuit 271 . That is, its output is given in accordance with equations 21 and 22 by the following equation (23 or 24).

B (-P _r [1] + G _r [1] -P _r [2] + G _r [2] +.. -P _r [i] + G _r [i]) (Equation 23)

or

B (-P _r [1] + G _r [1] -P _r [2] + G _r [2] +.. -P _r [i]) (Equation 24)

(B is a constant).

FIG. 31 shows an example of a construction of a recording condition judging circuit 711 in FIG. 27.

The circuit 722 performs a calculation of each P _r [i] -G _r [i] in FIG. 26 and a calculation for obtaining the sum of the repeated signals, and transmits the result of each calculation to the controller 272 . Buffer circuits 901 and 902 and a subtraction circuit 903 correspond to a section for extracting the value of each B (P _r [i] - G _r [i]) from the edge interval data represented by Equations 23 and 24 and from the edgeinterinter vall measuring circuit 10 are sent. The binary replay signal 277 is supplied to the latch circuit 901 as a signal for triggering. The edge interval data are sampled and held on the leading edge of the trigger signal. That is, when the binary reproduction signal 277 rises, the data represented by the equation 23 is held and output. In the latch circuit 902 , the data is delayed by the duration of a single trigger signal.

The subtraction circuit 903 subtracts an output of the latch circuit 901 from an output of the latch circuit 903 of the edge interval data and generates the subtraction result. An output of the latch circuit 902 and an output of the latch circuit indicate the result, which is represented by the equation (23) and differs only by a trigger signal. Therefore, B (P _r [i] - G _r [i]) is obtained by the output of the subtraction circuit 903 .

An adder 904 and a shift register 905 compute the sum of each B (P _r [i] - G _r [i]) of the respective data. The number of stages of the shift register 905 is dimensioned to be equal to the number of pulses in one period of the recording signal shown in FIG. 25. An output line is output at each stage and transmitted to the control device. At a time when the last playback signal 402 has been read out, the output result of each level of the shift register indicates the sum of B (P _r [i] - G _r [i]) in the repetition data for each i. Therefore, a check is made to determine whether the light beam intensity in recording or the temperature of the recording medium have changed based on a judgment reference curve shown in Fig. 26 and using the above result.

FIG. 32 shows an example of a structure of an edge position setting circuit 274 and an edge position setting table 275 of FIG. 27.

In the above circuit, the functions Cf () and Ce () in the equations (18 and 19) are obtained by referring to the contents of the edge position setting tables 15 and 16 , which are constructed by means of memory elements such as RAMs or the like. That is, when F [i] is obtained, pulse / split intervals L [i-1] and B [i-1] of the recording signal 301 as elements of the first and second parameters in the function Cf () and amounts that Specify edge position setting amounts F [i-1] and E [i-1] as the results of the conversion just before obtaining F [i] through an address signal line leading to the edge position setting table 275 , so that F [ i] is output as a function value from a data signal line. Likewise, when E [i] is obtained, the pulse / gap intervals B [i-1] and L [i-1] of the recording signal 301 as elements of the first and second parameters in the function Ce () and the amounts, which indicate the edge position setting amounts E [i-1] and F [i], as results of the conversion just before the extraction before E [i] via the address signal line leading to the edge position setting table 16 , so that E [i] is output as the function value of the data signal line.

Counter circuits 1001 and 1002 determine which number of basic clock intervals of the modulation signal correspond to the pulse / gap intervals of the signal transmitted by the modulation circuit 273 , and are connected to address lines of the edge position setting tables. On the other hand, latch circuits 1003 , 1004 , 1005 and 1006 are used to set the timings of the edge position setting table 275 and each of the address signal lines connected. Shift register circuits 1007 and 1008 are used to set the timings of the modulation signal and the edge position setting amounts. A selector circuit 1009 is a circuit for alternately switching the edge position setting amounts on the leading edge and the trailing edge. A programmable delay line circuit 1009 is a circuit for delaying the edge position by a duration corresponding only to the edge position setting amount, thereby setting the edge position. Therefore, an output signal of the programmable delay line circuit is supplied to the laser driver circuit 7 as setting signal 302 .

FIG. 33 shows an example of a structure of the edge position setting table 18 in FIG. 27.

The switching circuit 278 is constructed by: a data buffer 1102 which switches the contents in the edge position setting table in accordance with the temperature change of the recording medium and in which the data of the edge position setting amount of each linear recording speed in the useful area and each temperature of the recording medium have been saved; and a circuit for controlling the switching operation of the data buffer.

As a result of the detection in the recording condition judgment mode, when it is determined that a change in the contents of the edge position setting table is necessary, and in the case where the light spot moves and the linear speed changes, a table change command signal from that Controller 272 is supplied to a counter circuit 1101 , beginning with the changes in the contents in the edge position setting tables 275 and 276 . In the content changing operation, the speed of movement of the light spot on the recording medium and the temperature of the recording medium detected in the recording condition judgment mode are first supplied to the data buffer 1102 for the conversion table, thereby determining which of the im Data buffer 1102 is selected for the edge position setting tables stored in the conversion table. Each edge set amount is transferred from the data buffer 1102 for the conversion table at each address number provided by the counter circuit 1101 and stored in each conversion table. One of the outputs of the counter circuit is used as a table switching signal to select one of the edge adjustment amount tables 275 and 276 . The remaining signals are used as the address signals of the data buffer 1102 for the conversion table and the edge position setting circuits 275 and 276 .

Above is an embodiment of the present invention have been described. By using a process for calculating a recording pulse edge setting amount, it is possible to calculate the fluctuation amount of the flan kenposition in the playback wave to eliminate the is caused by the mutual heat disturbance that occurs because the previous recording pattern in the same recording pulse fluctuates.

As special areas for measuring the record conditions are used, areas will several positions on the inner groove, the outer Groove and an intermediate groove on the plate used. Such areas can be specifically provided be or as general data recording areas be made up. If in the data recording areas in the latter case, recording data already exists  other areas of the room are used or a process is performed to determine the data in the data data written temporarily in a drawing area other location such as a store in the control room device or the like to back up such data to use the recording area.

The present invention is applicable to all information recording systems and on recording media be applied on the principle of heat exploitation based. The present invention relates in particular a control method of the recording conditions such as the recording power and the recording pulse tervalls, which in a rewritable Informati ons Recorder and rewritable Information recording media are effective. In particular re, the invention represents a technique for the Ge ensuring the reliability of the recorded data in cases of recording methods and recording me are indispensable where a high heat diffuser is obtained and the opposite recording Conditions are sensitive, which is a difference the recording characteristics due to a small Change in recording performance, ambient temperature structure of the recording medium, the characters risks of the recording device and the like eats. E.g. the present technique is important for Si Creation of practical use, for example a magneto-optical disk, a rewritable ma gneto-optical plate, which the exchange coupling force uses a rewritable optical disc that has a Uses phase change, and the like.

As described above, according to the present invention If the test record is carried out, the result will be  of the test record is processed arithmetically, that is Record and control signal received and can Edge position using the edge position setting circuit based on such a signal on egg ne desired position can be controlled.

According to the present method for signal recording and playback can fluctuate the component the edge position of the playback signal by the mutual heat disturbance is caused to be eliminated. On the other hand, to master the case in which the Beam intensity during recording or the tem temperature of the recording medium changes, can always optimal recording conditions can be realized. Using a higher density record the mark length record can be easily and without difficult setting in manufacturing will. In addition, the reliability is considered Lich improved the recording data.

Embodiment 8

The embodiment relates to a method for entanglement a high-density recording by changing one Recording density according to the disk position and through the record.

In a recording process such as an MCAV, in which is the speed of the disc-shaped recording medium is set to a predetermined value and the recording when changing the linear speed in dependency ability to change radial recording position is running, it is for recording and playback of data with high reliability Ensuring high capacity is desirable  the sizes of the respective phase noise between the The inner groove and the outer groove of the plate are the same.

The phase noise is mainly divided into two components such as phase oscillation due to Zu fall noise such as a general noise, a Laser noise, amplifier noise and the like of the disk medium in the case of the above edge recording occurs, and divides an edge shift at which the edge position of the domain due to a difference the pattern of the lengths of the recording domain and on due to the mutual heat disturbance between the patterns changes. Since the medium of the magneto-optical disk is a good t has thermal conductivity, the medium in particular on the inner groove with low linear speed due to the warmth of the directly recorded Impulse influenced, so that a phase shift be regarding the position of the next In formation domain occurs and becomes larger than the Pha senoscillation. Thus, the information cannot be accurate are reproduced.

Now consider a method by which the linear density is determined in the case where an almost concentric track of the magneto-optical disk is divided into zones 1401 , 1402 and 1403 , which contains multiple tracks, as shown in FIG. 40. The linear recording density is the same in every zone. It is now assumed that a radial position of the innermost groove zone of the magneto-optical disk is set to R _min , that a linear density of the nth zone from the inside is set to L _n , that the number of sectors of the innermost groove is set to N _i is set, the number of data bytes per sector is set to B, a track pitch is set to p, the number of tracks in the zone is set to M ge, and a usage efficiency of data is set to η. In this case, the capacity of the innermost groove zone results

2π · R _min · L _i · η = N _i · B (Equation 25).

The following applies in the nth zone

2π · (R _min + n M · p) · L _n · η = (N _i + n) · B (Equation 26)

A difference between the linear density of the nth Zo ne and the linear density of the (n + 1) th zone

L _n + 1 - L _n = n (B - 2π · M · p · L _n · η) / 2π (R _min * M · p) · η (Equation 28).

Therefore, the linear density can be controlled by the size relationship between B and 2π · M · p · L _n · η. According to the present invention, since the user wants to improve the linear density on the outer groove side rather than the inner groove side, on which the amount of occurrence of the phase shift is large, the number M of the tracks and the track pitch P become so chosen that the following relationship is obtained.

L _n <B / (2π · M · p · L _n · η) (Equation 28).

For example, if an adjustment is made to increment each zone by one sector / track using 2-7 modulation, and it is assumed that a track pitch is 1.6 µm and an innermost groove recording radius is 67.9 mm and the number of sectors of the inner groove is 52, a value as shown in Fig. 36 changes depending on the value of M. The shortest pit length of the 2-7 modulation is used as the ordinate axis instead of the linear density. Since the shortest pit length is small, the linear density increases.

Now, the results of the above study are considered from the viewpoint of the recording capacity. When the linear density at the radial recording position is controlled so that the linear density at the outer groove is increased and the linear density at the inner groove is reduced, as shown by a solid line 1100 in Fig. 34, the proportion has the Memory capacity a curve as shown by a solid line 2100 in Fig. 35. Fig. 35 shows a capacity per track in which the linear velocity is multiplied by the length of the circumference of the radial position. A total storage capacity is obtained by integrating such a capacity from radius R _i to radius R₀. In Figs. 34 and 35 show the unterbro rupted lines 1200 and 2200 in the case in which the linear density is set to a predetermined value. From Fig. 35, it can be seen that compared to such a linear density, even with a reduction of the linear density on the inner groove side, little influence is exerted on the total storage capacity because the portion of the capacity on the inner groove side is small is. More specifically, there is a method of changing the linear density of the individual zones 1401 , 1402 and 1403 shown in FIG. 40.

If a facility with a large storage capacity through a combination of a medium of a magnetoopti edge recording using the MCAV- Processes can be realized according to the invention  the phase fluctuation amounts at the inner groove and at the outer groove, which indicates the reliability of the data give almost be balanced, so that a ring Storage capacity can be avoided.

Embodiment 9

The embodiment relates to a structure in an area is provided on the plate in which egg ne test record is run to control parameters to get that required when the record control is executed.

The present invention will now be described in detail using an embodiment. First is a schematic diagram showing a cross-sectional structure of a plate formed, similar to Fig. 21. The plate produced has a five-layer structure, which is obtained by successively 50 SiN _x (75 nm) 51 on a polycarbonate substrate, TbFeCoNb (30 nm) 52 , SiN _x (20 nm) 53 , Ni (30 nm) 54 and Al (30 nm) 55 can be layered on. The plate is formed by a sputtering process. As a condition for the sputtering process, the air is evacuated to a vacuum of 10 ^-7 Torr. Thereafter, the silicon nitride film 51 is first formed on the polycarbonate plate substrate 50 . Pure Si is used as the target substance, while Ar / N₂ mixture gases are used as the discharge gas and the sputtering process is carried out with an electrical HF switch-in density of 6.6 mW / cm² and a discharge gas pressure of 10 mTorr, which results in a film is formed with a thickness of 75 nm. Then, the magnetic optical TbFeCoNb recording film 52 is formed. A TbFeCoNb alloy is used as the target substance, a high-purity Ar gas is used as the discharge gas, and the sputtering process is carried out with an electrical RF switch-on power density of 4.4 mW / cm² and a discharge gas pressure of 5 mTorr, which results in a film with a thickness of 30 nm is formed.

The silicon nitride 53 is then formed again. Pure Si is used as the target substance, an Ar / N₂ gas mixture is used as the discharge gas, and the sputtering process is carried out at an electrical HF switch-on power density of 6.6 mW / cm² and at a discharge gas pressure of 10 mTorr, which results in a Film with a thickness of 20 nm is formed.

Then, the Ni film 54 is formed. That is, that Ni is used as the target substance, that high-purity Ar gas is used as the discharge gas, and that the sputtering process is carried out at an electrical RF switch-on power density of 3.3 mW / cm² and at a discharge gas pressure of 15 mTorr, whereby a Film with a thickness of 30 nm is formed. Finally, the Al film 55 is formed. That is, Al is used as the target substance, high-purity Ar gas is used as the discharge gas, and the sputtering process is carried out at an electric RF turn-on power density of 3.3 mW / cm² and at a discharge gas pressure of 15 mTorr, whereby a Film with a thickness of 30 nm is formed.

The film surface of the magnetoop made as above Table top is made with a resin from ultraviolet hardening covered the guy. Furthermore, two plates by means of egg glued together, which creates a magne tooptic plate is formed. A structure of here plate used is only given as an example, the effect of the present invention not on this structure of the plate is limited. Although the  the above disc is a one-layer recording film it can also be used on an optical disc, using the exchange coupling function can be written. Furthermore, the present invention obviously also on the recording and the Control of an opti taking advantage of a phase change plate applicable.

Fig. 39 shows a plan view of the plate that has been prepared as mentioned above. When the disk drive of such a disk has been put into operation, the data is recorded on a test track 1400 for recording and control as shown in FIG. 39 by means of a test pattern 21 shown in FIG. 37. The recorded data is played back. By measuring a change in an amplitude of the reproduction signal, a fluctuation in the shape of the magnetic domain caused by external factors is detected. Based on the detection result, user data is recorded in a recording area by controlling at least the laser power in the recording, the recording pulse width or the shape of the recording pulse.

Fig. 38 shows a schematic representation of the shape of the magnetic domain of the recording obtained at this time. If the recording is carried out without control, a teardrop-shaped magnetic domain is formed, the width of which is increased because the width of the magnetic domain is not controlled, or the length of which is increased or decreased because no control is carried out, which is a case generation of errors occurs when the user attempts to perform the Pitrand recording. A major factor in the occurrence of such changes is a fluctuation in the ambient temperature used. Therefore, when the disk drive is started up or the disk is inserted, data is recorded on the test track 1400 for recording control using the test pattern. By reproducing the recorded information, the ambient temperature used is detected. The detection result is fed back when the recording conditions are set, and the recording is carried out in consideration of the environmental conditions and the problem is solved. Therefore, even if the ambient temperature changes, the size of the domains recorded on the disk 1 is always constant.

Therefore, high density recording can be carried out the. If there is a fluctuation in the media drawing sensitivity or the like is present, the sizes of the domains differ on the respective plates are formed, so here is a case generation of errors is present. If the present Invention is used, the ge in the disk drive stored test samples in advance on the invention intended test track recorded, whereupon the aufz calibrated data are reproduced and the amplitude of the signal obtained is measured, so that not only the fluctuation under the plates, but also the one be solved by the change in ambient temperature can. The information for the control by means of the Test sample is collected exactly when the plate run works or the plate is inserted.

According to the embodiment, the recording area of the disc 1 has been divided into a plurality of zones 1401 , 1402 and 1403 in advance, the area 1400 for collecting the information for executing the recording control in each zone and the test pattern in such an area is recorded or reproduced from such an area. Therefore, a difference in the sizes of the magnetic domains of the recording that occurs due to a fluctuation in the ambient temperature, a fluctuation in the media, or the like can be corrected. Since an amount of fluctuation changes depending on the disk position, the test track is provided at least in each of the zones 1401 , 1402 and 1403 , whereby this problem can be solved. As a result, the optical recording can be realized with super density. By creating a test area in each track, it is effective for preventing deterioration of the medium of the test track that can make the correction more accurately by not overlapping the test record in the same place as where the test record has already been performed is to be executed or not to continuously execute the test record, thereby preventing the number of rewrite operations of the test track from being one-sided.

When the test record is made on the test tracks 1400 of the inner groove, the middle groove and the outer groove of the disk as mentioned above, the recording and reproducing characteristics in each of the zones 1401 , 1402 and 1403 are stored in advance in a storage device, so that the recording and reproducing characteristics of the disc can be extrapolated in the zone where the test record is not being performed.

Claims (30)

1. Optical disk storage device with a light source ( 8 ), an encoder ( 4 ) for converting an information signal to be recorded into a code train,
a light source driver ( 7 ) for modulating a light beam from the light source ( 8 ) in accordance with the code train and for recording the modulated code train as a recording mark on the optical disc ( 1 ), a detector ( 9 ) for photoelectric conversion of the light coming from the optical disc ( 1 ), a signal processing device ( 11 ) for processing the waveform from the detector ( 9 ), a pulse shaping device ( 13 ) for obtaining a pulse signal from the waveform, a discriminator ( 15 ) for the detection of the code train recorded on the optical table ( 1 ) from the pulse signal, a decoder ( 17 ) for decoding the code train from the discriminator ( 15 ) into the information signal, and a control unit ( 6 ) which depends on the light beam modulated by an output signal of a comparative discriminator ( 16 ) and at least ent either a power level, a Pulse width and a pulse interval from the light pulse train forming pulses controls sen, characterized in that
a test writing device ( 3 ) is provided which generates a test pattern in a test write area on the optical disk ( 1 ) in accordance with a test signal, the comparison discriminator ( 16 ) compares the read test pattern with the test signal and
the control device ( 6 ) modulates the light beam depending on the comparison in such a way that

• a recording power level is P _w or greater,
• a second non-recording power level having the value, and
• - At least on the front or back of the light pulse train forming the record mark, a power level has the value P _r , where: P _w <P _as <P _r .

2. Optical disk storage device according to claim 1, marked by a control device for controlling the modulation the light beam by choosing the power level, the pulse width or the pulse interval from given values. 3. Optical disk storage device of claim 1, characterized in that the test pattern is encoded by the test writing means (3) from the encoder (4) according to and is recorded. 4. Optical disk storage device according to claim 1, characterized by a changeover switch ( 12 ) with which the electrical signal wave in the pulse shaping device ( 13 ) is supplied without running through the wave processing device ( 11 ). 5. Optical disk storage device according to claim 1, characterized in that  the light pulse train of one of the recording marks unit forming a leading impulse and egg NEN subsequent pulse train, the temporal Spread below that of the leading impulse separates. 6. Optical disk storage device according to claim 5, characterized in that the following pulse train is a pulse train at at least either the temporal latitude of the impulse or the pulse interval is the same. 7. The optical disk storage device according to claim 1. characterized in that the light pulse train of one of the recording marks unit forming impulses with two or more Power levels. 8. An optical disk storage device according to claim 7. characterized in that in the light pulse train one of the recording mar unit forming the power level of the guide impulse from the power levels of the follow the impulses are different. 9. An optical disk storage device according to claim 1, characterized in that the control device the number of pulses of light pulse train one of the recording marks controls unit. 10. Optical disk storage device according to claim 1, characterized in that the control device changes at least either P _w or P _as or P _r . 11. The optical disk storage device according to claim 1, characterized by means ( 270 , 271 , 272 ) for controlling the edge positions of the pulses forming the light pulse train on the basis of at least one of the combinations of a temperature of the optical disk, a linear speed of the recording on the optical disc and the recording mark based on the information signal to be recorded. 12. An optical disk storage device according to claim 11, characterized by Tables (275, 276) for storing information to control the edge positions. 13. Optical disk storage device according to claim 1, characterized in that the optical disk ( 1 ) is divided in the radial direction into a plurality of zones ( 1401 , 1402 , 1403 ) with different recording conditions and that in each zone an area ( 1400 ) for recording of the test sample is provided. 14. Optical disk storage device according to claim 1, characterized in that the optical disk (i) is divided in the radial direction into a plurality of zones ( 1401 , 1402 , 1403 ) in which the linear recording density in the same zone is the same and in which the linear Recording density of the region ( 1401 ) located at the innermost groove of the optical disk is the smallest. 15. An optical disk storage device according to claim 14, characterized in that the optical disk ( 1 ) uses a light pulse train for the adjustment of the linear recording densities such that at least either the pulse width or the pulse interval in each zone or in accordance with the radial position of the Plate who changed. 16. An optical disk storage device according to claim 1, characterized in that the comparison result represents at least one variable, that of the width, the length and the marking interval vall of the recording mark is selected. 17. An optical disk storage device according to claim 1, characterized in that a record clock is used, at least either the pulse width or the pulse interval of the to control the light pulse train, and is set to a value that is a fraction of a gan zen number or an integer multiple of an entry solution window width is that by the recording clock is formed. 18. Optical disk storage device according to claim 1, characterized in that the light source driver device ( 7 ) is constructed such that a plurality of unit driver circuits, each containing a switching device and a power source connected in series, are connected in parallel, with each of the unit driver circuits a constant current source is connected in series, a light source ( 8 ) being connected in series with the constant current source and in parallel with the unit driver circuit, the current sources of the plurality of unit driver circuits being constructed in such a way that they deliver currents with different values and a value of Current that drives the light source ( 8 ) is controlled by the fact that the switching device is actuated by a control signal based on the code train. 19. An optical disk storage device according to claim 18, characterized in that at least one of the power sources of the unit drivers circuits a current can vary. 20. An optical disk storage device according to claim 18, characterized in that the switching device is a switching element of the NPN type.   21. A method for recording and reproducing optical information, comprising the steps of: converting an information signal to be recorded into a code train; Modulating a light beam in accordance with the code train ( 20 ); Directing the light pulse train onto a recording medium ( 1 ); Recording the code train ( 20 ) as a recording mark by at least either the heat effect or the mutual heat disturbance of the light pulse train; photoelectric converting the light from the recording medium ( 1 ) to thereby obtain an electrical signal wave; Processing the electrical signal wave; Converting a signal derived in the wave processing device into a pulse signal; Detecting the code train recorded on the recording medium from the pulse signal; and decoding the detected code train into the information signal, characterized in that the light beam is modulated by a special test signal, a test pattern is formed on the recording medium, the test pattern is reproduced and compared with the test signal and at least one of a power level, a pulse width and a Pulse interval of the light pulse train building pulses are controlled based on the comparison result, the light pulse train of a unit forming one of the recording marks having a pulse with a power level of P _w or higher and the non-recording light pulse train having a power level Pas or less and At least either at the front or at the rear of the light pulse train forming the record mark, a region with a power level of P _{r is} provided, with P _w <P _as <P _r . 22. Process for optical recording and reproduction of Information according to claim 21, characterized in that every time the recording medium is replaced, the light beam is modulated by the special test signal thereby the test pattern on the recording medium form, the test sample is reproduced and with the test si gnal is compared and at least either the lei power level, the pulse width and a pulse interval of the impulses building up the light pulse train on the Be controlled based on the comparison result. 23. Method for optical recording and reproduction of Information according to claim 21, characterized in that  the test sample has a longest and a shortest code contains. 24. An optical disk according to claim 1, for recording information by forming a recording area by means of a thermal effect by irradiation with a laser beam, characterized in that the optical disk ( 1 ) radially into a plurality of concentric zones ( 1401 , 1402 , 1403 ) is divided with different recording conditions and an area ( 1400 ) for recording the test pattern is provided in each zone. 25. An optical disc according to claim 24, characterized in that a linear recording density in the same zone of the optical disc ( 1 ) is the same and a linear recording density of the zone ( 1401 ) located at the innermost groove of the optical disc is smallest. 26. The optical disc according to claim 24, characterized in that the optical disc by sequential stacking layers of a substrate, a first dielectric Layer of an inorganic compound that is not optically absorbed, a recording layer with a perpendicular magnetic anisotropy, a second di electrical layer made of an inorganic compound, which is not optically absorbed, and a control layer for the execution of the reflection of light and the Control of heat flow and from a protective layer for the execution of the protection of each of the layers ten and the control of the heat flow is formed.   27. The method according to claim 21, characterized in that information is recorded by a recording area is formed by means of a thermal function by irradiating a laser beam onto an optical disk rotating at a constant speed, the optical disk being concentric in the radial direction in a plurality zones ( 1401 , 1402 , 1403 ) is divided with different recording conditions and the recording area is formed so that a linear recording density in the same zone is the same and a linear recording density in the zone located at the innermost groove of the optical disk ( 1401 ) is the smallest and a linear recording density of the region ( 1403 ) located at the outermost groove of the optical disk is the greatest. 28. Laser driver circuit for an optical disk storage device according to claim 1, characterized in that multiple unit driver circuits, each one Switching device and a series connected to it Current source contains, arranged in parallel, a Kon Constant current source with each of the unit driver circuits gen is connected in series, a semiconductor laser with the Constant current source in series and to the unit driver circuit is connected in parallel, the current sources of the several unit driver circuits are constructed that they deliver currents with different values, and a Value of a current to drive the semiconductor laser through Actuation of the switching device by means of a control signals is controlled.   29. Laser driver circuit according to claim 28, characterized in that at least one of the power sources of the unit drivers circuits the current can vary. 30. Laser driver circuit according to claim 28, characterized in that the switching device is a switching element of the NPN type.