JPH11149641A - Optical recording method and optical recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform recording with proper light intensity even when a temperature change occurs and to prevent a reduction in a processing speed by holding information regarding the upper and lower values of light intensity for allowing normal recording in the specified place of a recording medium or a recording device and performing test recording by light intensity based on this information during test recording. SOLUTION: A reproducing circuit 9 calculates a recording condition by a control circuit 10 according to a rest recording area based on reproducing information obtained by restoring the reproducing signal of an optical head 5. A temperature sensor 8 detects the temperature in an optical recording device 1a or of an optical disk 2, inputs a signal to the control circuit 10 and, when the temperature is changed by a specified value or more, a plurality of test patterns recorded at the time of test recording stored in a memory 7 are read, and then a test recording operation is started by a modulation circuit 6. An arithmetic and logic unit 11 calculates optimal intensities for all recording areas at the time of information recording based on the recording condition calculated by the control circuit 10. Then, during test recording, the table of optimal recording power for each zone of an optical disk 2 is made by the arithmetic and logic unit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical recording method and an optical recording apparatus, and more particularly to a test recording method and an optical recording apparatus for an optical disk.

[0002]

2. Description of the Related Art Recently, an optical recording / reproducing method which satisfies various requirements including a high density, a large capacity, a high access speed, and a high recording / reproducing speed, a recording apparatus, a reproducing apparatus and a recording medium used therefor Efforts have been made to develop a magneto-optical recording method, a phase change recording method, and the like.

[0003] Among a wide range of optical recording / reproducing methods, the magneto-optical recording / reproducing method allows information to be recorded and then erased, and that new information can be recorded again and again. Since it has excellent features, it can be said that it is the most practical reproduction method. A magneto-optical recording disk (medium) used in this magneto-optical recording / reproducing method has a single-layer or multi-layer magnetic film as a layer for recording. As the magnetic film, a perpendicular magnetization film having a high recording density and a high signal intensity has been developed and used. Such a magnetized film is
For example, amorphous GdFe, GdCo, GdFeC
o, TbFe, TbCo, TbFeCo and the like.
The perpendicular magnetization film generally has a concentric or spiral track, and information is recorded on the track.

In recording marks (information), a laser is used.
Effective spatial and temporal cohesiveness, which is a feature of
And the diffraction limit determined by the wavelength of the laser light
Beam is narrowed to a small spot almost as much as the world
I will. The narrowed light is applied to the track surface and recorded.
Heat the recording film to form a mark with a diameter of 14 μm or less on the recording film.
By doing so, information is recorded. Optical record smell
Theoretically, about 10 ⁸ Mark / cm^Two Recording density up to
Can be achieved. Because the laser beam
Is a spot with a small diameter almost as much as its wavelength.
This is because it is possible to agglomerate even to the point.

[0005] In magneto-optical recording, a laser beam is focused on a perpendicular magnetization film and heated. in the meantime,
A recording magnetic field Hb in a direction opposite to the initialized direction is externally applied to the heated portion. Then, the coercive force Hc of the locally heated portion decreases and becomes smaller than the recording magnetic field Hb. As a result, the magnetization of that portion becomes the recording magnetic field H
Line up in the direction of b. In this way, a reversed magnetized mark is formed.

[0006] Light is an electromagnetic wave having an electromagnetic field vector that diverges in all directions, usually on a plane perpendicular to the optical path. When the light is converted to linearly polarized light and illuminates the perpendicular magnetic film, the light is reflected at the surface or transmitted through the perpendicular magnetic film. At this time, the plane of polarization rotates according to the direction of magnetization. This rotating phenomenon is called a magnetic Kerr effect or a magnetic Faraday effect. For example, if the plane of polarization of the reflected light rotates by θK degrees with respect to the magnetization in the initialization direction, it rotates by −θK degrees with respect to the magnetization in the recording direction. Therefore, the axis of the optical analyzer (polarizer) is θK
If it is set perpendicular to the plane inclined at an angle, light reflected from the mark magnetized in the initialization direction cannot pass through the analyzer. On the other hand, the light reflected from the mark magnetized in the recording direction is multiplied by (sin2θK) ² , passes through the optical analyzer, and is captured by the detector (photoelectric conversion means). As a result, the mark magnetized in the recording direction looks brighter than the mark magnetized in the initialization direction, and generates a strong electric signal in the detector. Therefore, the electric signal from the detector is modulated according to the recorded information, and the information is reproduced.

Further, as another recording method of the magneto-optical recording method, a light modulation overwrite method (direct overwrite method) has been applied for a patent (Japanese Patent Application Laid-Open No. 62-1759)
No. 48 = DE3,619,618A1 = USP5,23
9, 524). In this recording method, a memory layer (hereinafter, referred to as an M layer) basically composed of a magnetic thin film capable of perpendicular magnetization.
And a recording layer (hereinafter, referred to as a W layer) composed of a magnetic thin film capable of perpendicular magnetization. Both layers are exchange-coupled, and only the magnetization of the W layer is changed at room temperature without changing the magnetization direction of the M layer. Is used, and an overwritable multi-layer magneto-optical recording medium that can be oriented in a predetermined direction is used. Then, a method is used in which recording is performed with a pulse-modulated laser beam (high level PH and low level PL) according to the binarized information.

On the other hand, as a recording medium used in the phase change recording method, for example, a GeSbTe-based medium capable of reversibly repeating a crystalline phase and an amorphous phase is used. This medium represents an erased state in a crystalline state and a record in an amorphous state. In the reproduction, a light beam is irradiated, and the light beam is converted into a strong or weak electric signal by using a difference in reflectance between a crystalline state and an amorphous state. This medium can also be overwritten with a laser beam modulated into a high level and a low level.

[0009]

When recording is actually performed on an optical disc, the light intensity (laser power) is adjusted according to the recording temperature, sensitivity, and environmental temperature of the disc in order to optimize the mark shape. Fine-tuning is required.
When recording with a recording power that deviates significantly from the optimum,
If the shape or size of the formed mark is different from the shape or size of the mark to be recorded, and the reproduced signal does not correspond to the recorded information even when the mark is reproduced, an error occurs and the information cannot be read.

[0010] The optimum light intensity is not only different for each disk surface, but also varies depending on factors such as the radial position on the disk, the temperature of the disk, and the temperature of the recording / reproducing apparatus for outputting a laser. At present, some commercially available optical disk recording apparatuses perform test recording to adjust sensitivity before recording information. To perform test recording, the power is changed at the inner, outer, or inner, middle, and outer circumferences of the disk, such as immediately after the optical disk is mounted on the drive device or when the temperature of the drive device changes during use. Repeat the reproduction to find the optimum recording power. In addition, in order to obtain the optimum recording power for all the areas that can be used for recording information, the optimum power is obtained by test recording in the innermost area and the outermost area, and test recording is performed by calculation from the two recording powers. There is also a method of finding the optimum power in an intermediate area where the above is not performed.

After the apparatus is started up, the temperature of the recording medium changes immediately after the insertion or replacement of the optical disk and during continuous use, so that the optimum light intensity of the laser beam changes accordingly. Therefore, recording cannot be performed accurately. To cope with this, it is necessary to frequently perform test recording when the environmental temperature or the like changes, and update the setting of the recording power. However, frequent test recording during use has a problem in that the actual processing speed is reduced.

Further, in the case of the above-described overwrite recording in which information is recorded on an overwritable optical recording medium by modulating at least the light intensity to be recorded to at least two levels of a high level and a low level, And at least two low-level recording powers are independently set. Therefore, it takes more time for test recording to find the optimum recording power. as a result,
There is a problem that the advantage of the high transfer rate of overwrite recording cannot be fully utilized.

An object of the present invention is to provide an optical recording method and an optical recording apparatus capable of recording at an appropriate light intensity even when a temperature change occurs and preventing a decrease in processing speed. And

[0014]

The optical recording method of the present invention comprises:
In an optical recording method of recording information by irradiating a recording medium with light, while sequentially changing the light intensity to be irradiated,
Performing test recording on the recording medium, obtaining at least one of an upper limit value and a lower limit value of light intensity capable of normal recording on the medium from the result of the test recording, and obtaining information on the upper limit value or the lower limit value. Is held in a predetermined location of the recording medium or the recording device, and when performing the next test recording, the test recording is performed with light intensity based on the retained upper limit value or the lower limit value. I do.

The range of light intensity for performing test recording may be determined based on the upper limit or the lower limit. Further, the next test recording may be performed after a lapse of a predetermined time from the test recording. Further, the next test recording may be performed when a temperature change is detected in the recording medium or the recording device.

The recording medium is a disk-shaped recording medium, and at the time of the first test recording after the power of the recording apparatus is turned on or after the loading of the recording medium, the recording medium has a plurality of radial positions on the recording medium. Test recording is performed, and at the time of the next test recording, one of the recording media
Test recording was performed at the radial position of the location,
The light intensity of the entire area of the recording medium may be determined based on the light intensity from the test recording at the location.

Also, the recording medium is a disk-shaped recording medium, and the upper limit value or the lower limit value of the held light intensity at the first test recording when the recording medium is replaced with another recording medium. The test recording may be performed in a plurality of areas in the radial direction of the recording medium while changing the light intensity based on the above.

Further, information may be recorded on the recording medium by using a light modulation recording method for modulating light intensity to at least two values. Further, the recording medium may be a recording medium capable of direct overwriting. Also, the optical recording apparatus of the present invention includes a rotating unit for rotating a recording medium, an irradiating unit for irradiating the recording medium with a laser beam, and controlling the intensity of the laser beam on information to be recorded on the recording medium. Recording means for performing recording on the recording medium; reproducing means for reproducing information recorded on the recording medium; and information obtained by the reproducing means for each of a plurality of test recordings performed by the recording means. A first determining means for determining at least one of an upper limit value and a lower limit value of the intensity of the laser beam capable of normal recording on the recording medium, based on the upper limit value or the lower limit value. And second determining means for determining the intensity of the laser beam when recording information.

[0019] Further, the apparatus has storage means for storing information relating to the upper limit value and the lower limit value, and when performing the next test recording, a laser based on the information stored in the storage means is provided. The test recording may be performed with the light intensity. In addition, a timer may be provided, and the recording unit may perform test recording when a signal indicating that a predetermined time has elapsed is output from the timer.

Further, the apparatus further comprises a temperature detecting means for detecting the temperature of the optical recording apparatus or of the recording medium. May be performed.

[0021]

FIG. 1 is a block diagram of an optical recording apparatus used in an embodiment of the present invention. In the figure, an optical recording device 1
a includes a drive motor 3 for rotating the optical disk 2 and an optical head 5 for recording, reproducing and erasing information by irradiating the focused laser beam 4 onto the disk surface. The optical head 5 can be moved in the radial direction of the disk by a coarse motor (not shown), and the position in the radial direction where information is recorded, reproduced, and erased can be changed.

The modulation circuit 6 modulates the light intensity of the laser beam 4 when performing test recording on the optical disk 2 according to a test pattern. The memory 7 stores a plurality of test pattern data to be recorded at the time of test recording. The temperature sensor 8 detects the temperature of the optical recording device 1a or the temperature of the optical disk 2, and outputs a detection result to the control circuit 10. The reproduction circuit 9 restores the reproduction signal from the optical head 5 as data and sends the data to the control circuit 10. The test pattern recorded on the optical disk 2 at the time of test recording is reproduced by the reproducing circuit 9.

The control circuit 10 obtains recording conditions corresponding to each test recording area based on the reproduction information obtained by the reproduction circuit 9. Further, the control circuit 10 receives a signal from the temperature sensor 8, reads out the test pattern data from the memory 7 when the temperature changes by a predetermined value or more, and sends the test pattern data to the modulation circuit 6. Starts the test recording operation. The arithmetic circuit 11 calculates the optimum light intensity in the entire recording area when recording information based on the recording conditions obtained by the control circuit 10.

FIG. 8 is a diagram showing another configuration example of the optical recording apparatus used in this embodiment. The optical recording device 1b of FIG. 8 uses a timer 12 instead of the temperature sensor 8 of the device 1a of FIG. The timer 12 outputs a signal to the control circuit 10 every time a predetermined time elapses. The control circuit 10b includes a timer 1
2 receives a signal indicating that a predetermined time has passed from the memory 7
The test recording operation is started by reading the test pattern data from. Other operations are the same as those of the optical recording device 1a of FIG.

In this embodiment, a direct overwriteable magneto-optical recording medium using a recording method of modulating the light intensity to a multi-level among recording media for recording information by irradiating light will be described as an example. In direct overwrite, a low-power and high-power laser beam is irradiated. Old information is erased by irradiating a low-power laser beam, and new information is simultaneously recorded by irradiating a high-power laser beam modulated according to information to be newly recorded. In particular, when the low power is not sufficient (too low), old information is not erased and new information is not recorded correctly. Since test recording is a process for finding the optimum power for recording or the permissible recording power, if correct power cannot be obtained, it will cause a significant decrease in reliability.

FIG. 2 is a sectional view of a magneto-optical medium capable of direct overwriting. A magneto-optical medium 20 capable of direct overwriting shown in FIG. 2, a dielectric layer 22, a memory layer 23, an intermediate layer 24, a recording layer 25, a switch layer 26, an initialization layer 27, and a dielectric layer 22, which are sequentially laminated on a transparent substrate 21, The protective film 28 is provided. As the substrate 21, a disk-shaped glass substrate with tracking grooves is used.
The dielectric layer 22 and the protective film 28 are SiN, and the memory layer 23 is TN.
bFeCo, the intermediate layer 24 are formed of GdFeCo, the recording layer 25 is formed of TbDyFeCo, the switch layer 26 is formed of TbFeCo, and the initialization layer 27 is formed of TbCo to have predetermined thicknesses. The memory layer 23 is a TM (Transition Meta)
l: transition metal) rich composition, the recording layer 25 is a RE (Rare earth: rare earth) rich composition having a compensation temperature between room temperature and Curie temperature.

The optical disk 2 is not limited to the above-mentioned magneto-optical medium 20, but may be a phase-change medium 30 capable of direct overwriting as shown in FIG. This phase change medium 30
Includes a dielectric layer 22, a recording layer 25, and a protective layer 28 sequentially laminated on a substrate 21. The recording layer 25 is formed of, for example, GeSbTe. The optical disc 2 used in this embodiment is divided into a plurality of generally concentric regions called zones, and the recording frequency differs depending on the zone. The recording frequency is higher in the outer zone.
Test recording is performed for each of these zones, and the optimum light intensity for recording information is determined. Therefore, in the recordable area of the optical disc 2, three test recording areas T1, T2, and T3 as shown in FIG.
Is provided. The test recording areas T1 and T3 are provided on the radially outer side and the inner peripheral side of the recordable area, respectively, and the remaining test recording area T2 is provided at the radial center of the recordable area.

The optimum recording power becomes larger toward the outer periphery. In the test recording, the arithmetic circuit 11 creates a table of the optimum recording power for each zone as shown in FIG. FIG. 5 is a diagram showing the modulation of the recording power and the reproduction power in the direct overwrite. The vertical axis represents the intensity of the laser beam, and the horizontal axis represents the light emission time.

In the figure, PL is a low level (erasing power) during test recording, PH is a high level (recording power),
Pr is a beam intensity (reproduction power) at the time of reproduction. In this embodiment, the recording power is obtained by the following procedure. (1) First test recording The optical disk 2 is mounted on the optical recording device 1a or 1b,
The optical disk 2 is rotated by the spindle motor 3. Then, the irradiation position of the light beam 4 is moved to the test recording area by moving the optical head 5 in the radial direction. The control circuit 10 reads the data of the test pattern from the memory 7 (step 101 in FIG. 10), sends the test pattern to the modulation circuit 6, and sets the power for test recording (step 102 in FIG. 10). The laser beam 4 is irradiated while changing the laser power in the three test recording areas T1, T2 and T3 to control the recording of the test pattern a plurality of times, and the optical head 5 is moved to each test area to record the test pattern. Play back (Fig. 1
0 step 103). The reproduction signal is sent to the control circuit 10 via the reproduction circuit 9, and the allowable range (upper limit, lower limit) of the recording power in each test recording area is obtained (step 104 in FIG. 10). As described above, the test recording immediately after the insertion of the disc is performed.

In the test recording as described above, the initial recording power (Pt0) uses one of the following three methods. In the first method, the value of the power (Pt0) at the time of test recording is stored in advance in, for example, the memory 7 in the recording apparatus, read out, and a test pattern is recorded based on the value. In the second method, the recording power for normal writing to a disk is stored in, for example, the memory 7 in the recording device, read out, and the power for test recording is determined based on the value. Record the test pattern. In the third method, information on recording power is previously written on the optical disc 2, and the information is read out.
The power at the time of test recording is determined based on the recording power based on the information, and the test pattern is recorded.

In this embodiment, test recording is performed so that the ratio between PH and PL is kept constant in each region. That is, PH
Is sequentially changed, PL is also changed to a value such that PH / PL becomes a predetermined value. The upper and lower limits of the recording power in the test recording area are obtained as follows. Power Pt0
After the test recording is completed or at the same time as the test recording, the test pattern is reproduced as described above, and the control circuit 10 obtains the number of error bytes from the reproduced signal. That is, the test pattern is compared with the reproduced data, and the number of bytes that cannot be reproduced normally is obtained.

Next, by repeating the test recording while increasing or decreasing the recording power sequentially from Pt0, the relationship between each recording power and the number of error bytes at the recording power can be obtained. FIG. 11 shows the relationship between the power and the number of error bytes when test recording is performed while sequentially increasing the power of PH when recording using the power modulation method shown in FIG. 5 from Pt0. In the first test recording, the optimal recording power differs depending on the difference in the optimal recording power for each medium and the temperature of the medium and the recording device. Therefore, it is necessary to perform test recording while changing the power over a wider range than in the second and subsequent times. It is.

According to FIG. 11, if the allowable number of error bytes of the reproducing system is 20, for example, the upper limit Pmax of the recording power is Pt18 and the lower limit Pmin is Pt5. The recording power when the user records information is from Pmax to Pmin
(It is preferable to select an intermediate value between Pmax and Pmin), and the recording power of the entire area is equal to the inner peripheral area T.
3. Determined by calculation from the results of test recording in the middle area T2 and the outer area T3. Further, the inner peripheral area T3,
The upper limit value and the lower limit value of the recording power in the middle area T2 and the outer area T3 are stored in a predetermined area of the optical disk 2 or a storage device (for example, the memory 7) provided in the recording apparatus.

(2) Second and Subsequent Test Recording After the first test recording is completed, the recording apparatus performs a recording operation or a reproducing operation at the recording power determined by the test recording (step 105 in FIG. 10). Optical recording device 1a
Alternatively, after the start of 1b, the temperature of the apparatus and the optical disk 2 mounted therein rises with time. Depending on the change in the ambient temperature, the temperature of the optical disk 2 may decrease. Accordingly, the optimum recording power changes. This temperature change can be detected by using the temperature sensor 8. That is, the control circuit 10
Inputs and stores the temperature information output from the temperature sensor 8 when the test recording is performed, and then continuously monitors the temperature information from the temperature sensor 8. If the temperature has changed by a predetermined value or more since the last test recording, control is performed to perform test recording again. In the case of the recording device 1b shown in FIG. 8, when the signal indicating that the predetermined time has elapsed is output from the timer 12, the test recording is performed again. That is, test recording is performed again when a temperature change equal to or more than a predetermined value is detected by the temperature sensor attached to the recording device, or when a predetermined time has elapsed since the previous test recording (step 106 in FIG. 10). In the second and subsequent test recordings, a power deviation due to a temperature change is expected from the previous test recording, but since the disk is not replaced, it is not necessary to change the power over a wide range as in the first test recording. That is, it is sufficient to perform test recording only within a narrower range than the first time including the previous upper limit and lower limit. Therefore,
The control circuit 10 reads the upper limit value and the lower limit value of the recording power in each test recording area stored at the time of the previous test recording (Step 107 in FIG. 10). Then, based on the upper limit value and the lower limit value, a range in which the recording power is changed in the current test recording is set (step 1 in FIG. 10).
08). When the temperature rises, the optimum recording power is expected to decrease. Therefore, it is preferable that the lower limit of the range in which the recording power is changed should include a value slightly lower than the previous lower limit. In this case, the upper limit may be set to a value equal to or slightly lower than the previous upper limit. If the temperature drops, the reverse is true. When the range for changing the recording power is determined, test recording is performed as in the first time (step 109 in FIG. 10), and the upper limit of the recording power,
The lower limit is determined (Step 110 in FIG. 10). The recording power when the user records information may be set to an intermediate value between the obtained upper limit and lower limit. The obtained upper limit value and lower limit value are stored in the memory 7 and read out at the time of the next test recording.

In the description, the modulation method shown in FIG. 5 has been described for convenience. However, a modulation method in which high power is further multi-valued (see FIG. 6) or a modulation method in which heat shutoff is added before or after high power light emission. It is needless to say that the same effect can be obtained by the method (see FIG. 7) and the modulation method in which the light emission at high power is pulsed. Next, an embodiment based on the above procedure will be described.

(1) Initial Test Recording First, an optical disc was prepared in which an optical recording medium capable of direct overwriting was formed on a transparent substrate. The power of the recording device was turned on, and the optical disk was inserted into the recording device. The recording device holds information on the light intensity at the time of test recording. The light intensity is read out, and test recording is performed while sequentially changing the light intensity. FIG. 13 shows the PH of the test record read from the recording device for each area. In the case of this embodiment, data indicating the range in which PH is changed in the test recording is stored in the memory 7 in the recording apparatus. Immediately after insertion, a test pattern consisting of a random pattern is modulated in each of the three areas of the inner circumference, the middle circumference, and the outer circumference as shown in FIG. 5, and test recording is performed while maintaining a constant ratio of PH and PL in each area. Was done. In the test recording, the number of error bytes was obtained from the reproduced signal each time recording was performed while changing the recording power.
FIG. 12 shows the relationship between PH (mW) and the number of error bytes on the inner circumference as a result of test recording on the inner circumference. Assuming that the number of allowable error bytes is 20, the upper limit of PH is 9.8 m.
W, the lower limit was 8.7 mW. From this value, the upper limit of the test recording on the inner circumference was set to 9.9 mW, and the lower limit was set to 8.6 mW. The upper limit value and the lower limit value of the next test recording were determined from the results of the test recording in each area, and these values were held at predetermined positions of the recording / reproducing apparatus. The light intensity when recording information in the data area was set based on the result of the test recording. (2) Second test recording Test recording was performed again about 10 minutes after the optical disk was inserted. The light intensity of the test record was determined by reading the upper and lower limits of the previous test record. Test recording was performed in the range of 8.6 mW to 9.8 mW on the inner circumference. The number of error bytes in the test recording is indicated by ▽ in FIG. The upper limit was 9.7 mW and the lower limit was 8.65 mW. The upper and lower limits of the test recording range set from the upper and lower limits of the first test recording and the appropriate light intensity range were determined. When new information was recorded in the data section and the reproduced signal was observed, only a signal of the new information was observed, and it was confirmed that the erasure and recording of the information were correctly performed.

That is, in the second test recording, an appropriate recording power was obtained in a test recording in a range narrower than the light intensity range (shown in FIG. 13) at the time of the first test recording. (3) Third Time and Later Once the disc is inserted into the recording device, the appropriate light intensity for recording, reproduction, erasure, etc. is mainly caused by a temperature change. For this reason, there is no great deviation from the first appropriate light intensity. For this reason, test recording is performed while changing the light intensity over a wide range immediately after the insertion of the disc, and the upper limit of the light intensity,
By obtaining the lower limit, in the next test recording, the test recording in the range including the upper limit value and the lower limit value is sufficient and appropriate power is obtained, and the time required for the test recording is shortened. It is sufficient to perform the third and subsequent test recordings in the light intensity range based on the upper and lower limits of the previous test recording.

Such test recording may be performed only when there is a change in the temperature of the recording device or the disk. For the range of the first test recording, information on the light intensity applied to the disc may be read, and test recording may be performed based on this intensity. Also, the test recording can be expected to be shortened by applying it to a disk autochanger or a jukebox that handles a plurality of disks.

[0039]

As described above, according to the present invention, the recording power can be set efficiently during test recording.
The time required for test recording can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical recording apparatus used in an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a magneto-optical medium capable of direct overwriting.

FIG. 3 is a cross-sectional view illustrating an example of a phase change medium capable of direct overwriting.

FIG. 4 is a diagram showing an arrangement of test recording areas when the optical disc is viewed from a direction perpendicular to a recording surface.

FIG. 5 is a view showing power modulation of direct overwrite.

FIG. 6 is a diagram showing another power modulation of direct overwrite.

FIG. 7 is a diagram showing another power modulation of direct overwrite.

FIG. 8 is a configuration diagram of another optical recording apparatus used in the embodiment of the present invention.

FIG. 9 is a diagram showing a table created based on the optimum recording power for each zone obtained by test recording.

FIG. 10 is a diagram showing a procedure of a recording method according to the embodiment of the present invention.

FIG. 11 is a diagram illustrating a method of obtaining upper and lower limits of recording power in test recording according to the embodiment of the present invention.

FIG. 12 is a diagram showing the relationship between the recording power and the number of error bytes during reproduction according to the embodiment of the present invention.

FIG. 13 is a diagram showing an allowable value of a recording power in each test recording area obtained according to the embodiment of the present invention.

[Explanation of symbols]

1a, 1b: optical recording device, 2: optical disk, 3: drive motor, 4: laser beam, 5: optical head, 6: modulation circuit, 7: memory, 8: temperature sensor, 9: reproduction circuit, 1
0: control circuit, 11: arithmetic circuit, 12: timer.

Claims (12)

[Claims] 1. An optical recording method for recording information by irradiating a recording medium with light, wherein test recording is performed on the recording medium while sequentially changing the irradiating light intensity. Determine at least one of the upper limit value and the lower limit value of the light intensity capable of normal recording to, and hold the information related to the upper limit value or the lower limit value at a predetermined location of the recording medium or the recording device, and An optical recording method, comprising: performing test recording with light intensity based on the held upper limit value or lower limit value when performing test recording. 2. The optical recording method according to claim 1, wherein a range of light intensity for performing test recording is determined based on the upper limit or the lower limit. 3. The optical recording method according to claim 1, wherein the next test recording is performed after a lapse of a predetermined time from the test recording. 4. The optical recording method according to claim 1, wherein the next test recording is performed when a temperature change is detected in the recording medium or the recording device. 5. The optical recording method according to claim 1, wherein the recording medium is a disk-shaped recording medium, and is used at the time of first test recording after turning on a recording apparatus or after loading the recording medium. The test recording is performed in a plurality of radial positions of the recording medium, and at the time of the next test recording, the test recording is performed at one radial position of the recording medium. An optical recording method, wherein the light intensity of the entire area of the recording medium is obtained based on the light intensity. 6. The optical recording method according to claim 1, wherein the recording medium is a disk-shaped recording medium, and at the time of the first test recording when the recording medium is replaced with another recording medium. An optical recording method, wherein test recording is performed in a plurality of radial positions of the recording medium while changing the light intensity based on the held upper limit or lower limit of the light intensity. 7. The optical recording method according to claim 1, wherein information is recorded on the recording medium by using an optical modulation recording method for modulating light intensity to at least two values. Recording method. 8. The optical recording method according to claim 1, wherein the recording medium is a direct overwriteable recording medium. 9. A rotating unit for rotating a recording medium, an irradiating unit for irradiating the recording medium with a laser beam, and controlling the intensity of the laser beam for information to be recorded on the recording medium, Recording means for performing recording on the recording medium; reproducing means for reproducing information recorded on the recording medium; based on information obtained by the reproducing means for each of a plurality of test recordings performed by the recording means, A first method for determining at least one of an upper limit value and a lower limit value of the intensity of the laser beam capable of normal recording on the recording medium;
An optical recording apparatus comprising: a determination unit for determining the intensity of a laser beam when recording information based on the upper limit value or the lower limit value. 10. The optical recording apparatus according to claim 9, further comprising storage means for storing information relating to the upper limit value and the lower limit value, wherein the recording means performs the next test recording. An optical recording apparatus for performing test recording with a laser beam intensity based on information stored in the storage means. 11. The optical recording apparatus according to claim 9, further comprising a timer, wherein said recording means performs test recording when a signal indicating that a predetermined time has elapsed is output from said timer. Optical recording device. 12. The optical recording apparatus according to claim 9, further comprising a temperature detecting means for detecting a temperature of the inside of the optical recording apparatus or of the recording medium, wherein the recording means is controlled by the temperature detecting means. An optical recording apparatus for performing test recording when a temperature change equal to or greater than a value is detected.