JP2002352462A - Optical recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the optimum light power in a short time by using a test light without applying a load to the laser diode. SOLUTION: Gradually decreasing the light power of the laser diode 24 emitting a light beam, it writes a predetermined test pattern in a medium 72, reads it to compare with the original test pattern, and calculates the number of data which do not match. If the number of the unmatching data exceeds a predetermined threshold, it regards the light power as the limit light power. The light power adjustment section 300 determines the optimum light power after adding a predetermined offset to this limit light power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical storage device using a rewritable medium such as an MO cartridge.
In particular, the present invention relates to an optical storage device that efficiently adjusts the light emission power of a laser diode to an optimum power when loading a medium.

[0002]

2. Description of the Related Art An optical disk has been attracting attention as a storage medium which is a core of multimedia which has been rapidly developing in recent years.
In addition to the conventional 128 MB and 230 MB, in recent years, high-density recording media such as 540 MB and 640 MB have been provided. For this reason, as optical disk drives, currently available 180 MB, 230 MB,
It is desirable to be able to use all media, such as 40 MB and 640 MB.

In recent years, in a personal computer which has been rapidly spread, a function of reproducing a compact disk (CD) known as a reproduction-only computer is indispensable.
In addition to the optical disk drive for D, it is impossible to mount an optical disk drive of a MO cartridge which is a rewritable optical disk device in terms of space and cost.

Therefore, in recent years, an optical disk drive that can use both an MO cartridge and a CD has been developed. This CD / MO shared type optical disk drive is designed to share the optical system, the mechanical structure, and the controller circuit for the CD and the MO cartridge as much as possible.

[0005] Incidentally, the MO cartridge used for the optical disk drive employs ZCAV recording (zone constant angular velocity recording) in which the medium track is divided into zones and the number of sectors in each zone is the same. The number of zones of the MO medium is 1 zone, 230
The MB medium has 10 zones, but in recent years, in a high density PWM recording medium such as 540 MB or 640 MB, the track pitch of the medium becomes narrower and the number of zones increases as the recording density increases. are doing.

That is, a 640 MB medium has 11 zones and 54 zones.
The 0 MB medium has 18 zones. Normally, in the case of an optical disk medium using an MO cartridge, there is a difference in the optimum recording power for each medium, so when loading the medium, test writing is performed for each zone to adjust the light emission to the optimum recording power. It is carried out.

Further, the conventional 128 MB or 230 MB medium is recorded by pit position modulation (PPM), and the light emission power may be a two-step change of erase power and recording power. On the other hand, P of 540MB and 640MB
In the WM medium, recording by a pulse train is employed to increase the recording density. In pulse train recording,
It is necessary to change the light emission power in three stages of erase power, first write power, and second write power.

[0008]

Therefore, when light emission adjustment is performed for each zone of a 540 MB or 640 MB medium having an increased number of zones, the type of light emission power is increased by pulse train recording, and the adjustment is extremely difficult. There is a problem that takes time. At the time of light emission adjustment, the actual PP
Compared to the instantaneous light emission in the M recording and the PWM recording, the laser diode is driven to emit light by the default value specified by the firmware for a relatively long time requiring adjustment. This substantially causes the laser diode to emit DC light. If light emission adjustment is performed with a high light emission power, the laser diode may be damaged, and deterioration may be accelerated.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and an optical storage device capable of efficiently adjusting light emission without burdening a laser diode even when the number of zones is large. The purpose is to provide.

In a conventional optical disk drive, the optimum write power used for writing data to a medium varies depending on the type of the medium and the temperature of the medium. Therefore, when a medium is loaded into an optical disk drive, a test adjustment test is performed on the medium, that is, a power adjustment process for determining an optimum power by performing a test write is performed.

In the conventional power adjusting process, as shown in FIG. 57, the write power given as the default power is used as the power of the start 401, and the writing and reading of the test pattern are repeated while the write power is reduced stepwise, for example. The number of data mismatches (the number of errors) is counted. As the light power decreases and approaches the limit power,
The limit power WPa at the limit point 404 where the number of data mismatches increases and exceeds 1000, for example, is determined.

Next, writing and reading of the test pattern are repeated while the write power is gradually increased from the start point 401, and the number of data mismatches (the number of errors) is counted. As you increase the write power and approach the limit power,
The limit power WPb at the limit point 406 where the number of data mismatches increases and exceeds, for example, 1000 is obtained.

As described above, the upper and lower limit powers WPa, W
If Pb is detected, the intermediate write power (W
Pb-WPa) / 2 is determined as the optimum write power WP-best.

However, in such a conventional write power adjustment process involving a test write in an optical disk drive, two limit powers must be detected while decreasing and increasing the write power starting from the start power. Therefore, there is a problem that it takes time to detect the limit power, for example, it takes time from loading the medium to the ready state.

Further, it is necessary to drive the laser diode at a high power for test writing in order to adjust the write power, so that a heavy load is imposed on the laser diode, and the write power adjustment is frequently performed during operation of the apparatus. The laser diode is accelerated,
There is a problem that the durability of the device is impaired.

Accordingly, another object of the present invention is to provide an optical storage device capable of appropriately determining the optimum write power by a test write without imposing a load on a laser diode in a short time. .

[0017]

FIG. 1 is a diagram illustrating the principle of the present invention.

(Light Emission Adjustment) According to the present invention, there is provided an optical storage device capable of adjusting light emission efficiently without imposing a burden on a laser diode even when the number of zones is large.

The optical storage device according to the present invention comprises a laser diode 10 for emitting a laser beam used for recording / reproducing a medium.
Has zero. At the time of recording on a medium, a drive current corresponding to a combination of a plurality of different specified powers is supplied to the laser diode 100 by a light emission current source. The light emitting current source is a register, D
The current value flowing from the light emitting current source is constituted by an A converter and a current source circuit, and is specified by a light emitting current instruction unit using a register and a DA converter. An automatic power control (APC) 138 for controlling the emission power of the laser diode 100 to a specified target power is provided. The automatic power control unit 138 controls, for example, to a specified target read power.

The laser diode 100 has a monitor light receiving element 10 for receiving a part of the laser beam and outputting a received light current.
2 are provided. At the time of recording on the medium, a specified subtraction current corresponding to the difference between the specified light emission power and the target read power is subtracted from the received light current to obtain a monitor current, and this monitor current is fed back to the automatic power control unit.

Therefore, the monitor current corresponding to the read power is fed back to the automatic power control unit 138 even when the erase power and the write power exceeding the target read power are emitted. The subtraction current source is composed of a register, a DA converter, and a current source circuit.
A subtraction current indicating section having a converter controls and flows the current source circuit. The monitor current obtained from the subtraction current source is read by the monitor AD converter 152 serving as a power measurement unit.

When the adjustment mode is set, the light emission adjustment processing unit sequentially instructs the D / A converter of the light emission current source to emit light at two predetermined test powers, drives the laser diode to emit light, and controls the emission of the subtraction current source. A prescribed subtraction current corresponding to two test powers is instructed to the reference DA converter, each test power is measured from the monitor AD converter of the monitor measuring unit, and based on the measurement results, a light emission current source and a subtraction current source are measured. Is obtained by linear approximation with respect to the current instruction value for an arbitrary power in the power table 1
Register at 80.

The light emission adjustment processing unit is specifically composed of a light emission coarse adjustment processing unit 162 and a light emission fine adjustment processing unit 164. In the state where the on-track control is released, the light emission coarse adjustment processing unit 162 sequentially instructs the D / A converter of the light emission current source to emit light at two predetermined test powers, drives the laser diode to emit light, and performs subtraction. A prescribed subtraction current corresponding to the two test powers is instructed to the DA converter of the current source, and each test power is measured from the AD converter of the monitor measurement unit.

Then, based on the measurement results at these two points, the relationship between the arbitrary power of the emitted light and the measured power value for monitoring, the relationship between the arbitrary light emitting power and the indicated current value for the light emission, and The relationship between the reference current value and the current reference value is obtained by linear approximation and registered in the power table 180.

The light emission fine-adjustment processing unit 164 sequentially instructs the D / A converter of the light emission current source to emit light at two predetermined test powers in a state where the on-track control and the automatic power control are turned on. The diode 100 is driven to emit light, and a specified subtraction current corresponding to two test powers is instructed to the DA converter of the subtraction current source, and the emission current is set so that the measured power by the AD converter of the monitor measurement unit becomes the target read power. Adjust the indicated value of the source D / A converter. Then, based on the adjustment results of the two points, the relationship between the light emission power and the current instruction value for light emission for an arbitrary light emission power is obtained by linear approximation, and the power table 180 is corrected.

As described above, in the light emission adjustment of the present invention, for example, the relational expression y = ax + b is obtained by linearly approximating the relation between the current instruction value y of the light emission current source and the light emission power x from the measured power specified by the two test powers. Slope a, which is a coefficient, and y-axis intersection b
, And a current instruction value to the emission current source at an arbitrary emission power x can be calculated. For this reason, the test power at the time of adjustment only needs to emit light at two points, and the load on the laser diode can be reduced by setting the test power at two points on the low power side.

The light emitting current source is a read power current source 10.
4, an erase power current source 106, a first write power current source 108, and a second write power current source 110. The read power current source 104 is a read power current for causing the laser diode to emit light at a first power level, for example, the read power level when the laser diode emits read power, erase power P, first write power, and second write power. Flow I0.

The erase power current source 106 outputs an erase power current I1 for causing the laser diode to emit light at the erase power when the laser diode emits the erase power, the first write power, and the second write power.
It is added to the read power current I0 and flows.

The first write power current source 108 generates a first write power current I2 for causing the laser diode to emit light at a second power level, for example, the first write power level when the laser diode emits the first write power.
Is added to the read power current I0 and the erase current I1 to flow.

Further, the second write power current source 110
When the laser diode emits the second write power,
A second write power current I3 for causing the laser diode to emit light at a third power level, for example, a second write power level, is added to the read power current I0 and the erase power current I1 to flow.

The light-emitting current instruction section includes a read power current source,
DA converters 136 to 144 for indicating respective current values of the first write power current source and the second write power current source
Are provided individually.

The subtracting current source includes an erase power subtracting current source 112, a first write power subtracting current source 114, and a second write power subtracting current source 116. The erase power subtracting current source 112 subtracts the light receiving current i1 corresponding to the erase power from the light receiving current i0 of the light receiving element when the erase power, the first write power, and the second write power emit light.

The first write power subtracting current source 114 subtracts the light receiving current i2 for the first writing power from the light receiving current i0 of the light receiving element at the time of light emission of the first writing power. Further, the second write power subtracting current source 116 subtracts the light receiving current i3 corresponding to the second write power from the light receiving current i0 of the light receiving element at the time of light emission of the second write power.

The subtraction current instructing section includes a DA converter 1 for instructing a current value of each of the read power subtraction current source, the first write power subtraction current source, and the second write power subtraction current source.
46 to 150 are individually provided.

When the medium loaded in the apparatus is a pit position modulation (PPM) recording medium, the light emission coarse adjustment processing unit 162 and the light emission fine adjustment processing unit 164 adjust each of the erase power and the first write power. The medium loaded on the device is pulse width modulated (PWM).
In the case of the recording medium, the light emission coarse adjustment processing unit 162 and the light emission fine adjustment processing unit 164 adjust each of the erase power, the first write power, and the second write power.

The light emission coarse adjustment processing unit 162 and the light emission fine adjustment processing unit 164 divide a medium zone obtained by dividing a track into a plurality of units in the radial direction into a plurality of regions, for example, an inner region, a middle region, and an outer region. I do. Then, for each of the innermost zone and the outermost zone of each area, adjustment is made at two points while designating the test power and measuring the emission power.
The adjustment value of the zone between the innermost zone and the outermost edge of the outermost zone is calculated and set from a relational expression of linear approximation between the test power and the measured power at two points.

For this reason, even if the number of zones is increased, light emission at the write power for adjustment is required only in the two zones of the inner circumference and the outer circumference, and the time required for adjustment involving light emission is greatly reduced. it can.

The light emission coarse adjustment processing unit 162 and the light emission fine adjustment processing unit 164 individually specify and adjust erase power and write power as test power. The light emission fine adjustment processing unit 164 adjusts the power table adjustment value (adjusted default value) adjusted by the light emission coarse adjustment processing unit 162.
, The instruction values corresponding to the test power for the DA converter of the light emission current instruction unit and the DA converter of the subtraction current instruction unit are calculated and set.

The light emission fine adjustment processing section 164 adjusts the optimum write power determined by the test writing of the medium to the write power registered in the power table as an adjustment value (default value).
Correction coefficient (offset ratio) expressed as a ratio based on
, The test power is multiplied by a correction coefficient to correct the test power to the optimum test power.

When the correction coefficient of the optimum power is given, the light emission fine adjustment processing section 164 compares the correction coefficient with a predetermined coefficient limit range having an upper limit value and a lower limit value of the correction coefficient, and deviates from the coefficient limit range. In this case, the power correction coefficient is limited to the upper limit or the lower limit.

The light emission fine adjustment processing section 164 also divides a zone of a medium obtained by dividing a track into a plurality of units in a radial direction into a plurality of regions with respect to an upper limit value and a lower limit value of a power correction coefficient.
The write power of the innermost zone of each divided area is determined as the minimum power to determine the lower limit ratio to the lower limit, and the write power of the outermost zone is determined to be the maximum power, and the upper limit ratio to the upper limit is determined. An arbitrary zone between the outer peripheral ends is calculated from a linear approximation relational expression between the lower limit ratio and the upper limit ratio to set the upper limit ratio and the lower limit ratio.
For this reason, it is not necessary to set the upper and lower limits for each zone, and the upper and lower limits can be easily set.

When the medium loaded in the apparatus is a pit position modulation (PPM) recording medium or a pulse width modulation (PWM) recording medium, the light emission coarse adjustment processing unit 162 performs an erase power and a first write power Is adjusted and registered in the power table. In contrast,
In the case of a pulse width modulation (PWM) recording medium, the light emission fine adjustment processing unit 164 registers the power ratio of the second write power based on the first write power in addition to the erase power and the first write power. The setting of the two write powers is calculated by multiplying the designated first write power by the power ratio.

In this case, the light emission fine adjustment processing section 164 registers each power and power ratio in the power table for each zone number, and sets the second write power in the same designated zone as the first write power in the designated zone. Calculate by multiplying by the power ratio. The power ratio is a value that changes with temperature.

In order to obtain a power ratio corresponding to the temperature, the light emission fine adjustment processing unit 164 calculates a power ratio y1, y2 at each of two different temperatures T1, T2 of the inner peripheral zone,
From the four points of the power ratios y3 and y4 at the two different temperatures T1 and T2 of the outer peripheral zone, two temperatures T
1. Two relational expressions y = a1.T + b1 and y = a2.T + b2 are obtained by linear approximation of the power ratio to T2.

Next, two slopes a of two linear relational expressions
For each of the y-axis intersections b1 and b2 of the power ratios 1, 1 and a2, two relational expressions a = α · N + β and b = by linear approximation for the two zone numbers N1 and N2 on the inner circumference side and the outer circumference side.
γ · N + δ is determined, and respective slopes α, γ and y-axis intersection β,
δ is registered in the power table.

The light emission fine adjustment processing section 164 stores the zone number N
Is specified, the gradients α, γ and the y-axis intersections β, δ of the relational expression of the power ratio with respect to the designated zone number N are read out, and the inclinations a1, a2 of the relational expression for the temperature T and the y-axis intersection b
1 and b2, and finally, the power ratio of the designated zone is calculated from the measured temperature T at that time.

The light emission fine adjustment processing unit 164 emits light with a pulse train of a number of second write powers corresponding to the erase power, the first write power, and the pulse width, and the target read power of the automatic power control unit 138 at the end of the light emission pulse train. In the case of recording by PWM which shifts to the next light emission pulse train by lowering to a lower value, the time product of the insufficient power with respect to the target read power and the time product of the first write power exceeding the target power are equalized to cancel each other. , The instruction value of the subtraction current i1 to the DA converter 148 of the first write current difference is reduced.

Thus, at the end of the pulse train of the PWM recording, the write power is reduced to zero or less than the read power. Because the power reduction control that compensates for
Automatic power control of stable write power is possible without causing drift of write power due to insufficient power. (Optimal write power adjustment) According to the present invention, there is provided an optical storage device capable of appropriately determining the optimum write power by a test write without imposing a load on the laser diode.

In order to achieve this object, the optical storage device of the present invention includes an adjustment timing determining unit for determining the necessity of a write power adjustment process for optimizing a write power for a medium, and an adjustment timing determining unit for determining whether the adjustment timing determination unit needs to perform a write power adjustment process. In response to this, a predetermined test pattern is written to the medium while gradually decreasing the write power, read out, compared with the original test pattern, and the number of data mismatches is counted. An optimum write power adjusting unit 300 including a write power exceeding a threshold value as a limit write power, and a write power adjusting unit that determines a value obtained by adding a predetermined offset to the limit write power as an optimum write power. Features.

For this reason, the adjustment processing for determining the optimum write power only needs to gradually reduce the write power from the start power and detect the lower limit side limit power. Halves the time required to detect Also, since high power is not required for the test light, the durability of the device can be improved without damaging the laser diode.

The write power adjusting section has at least two of the first power for erasing the recording pits of the medium and the second power for forming the recording pits as the write power, and gradually reduces the write power in a stepwise manner. At this time, the first power and the second power are changed in a predetermined proportional relationship. Also, when gradually decreasing the write power,
The variation ratio of the second power may be changed so as to be smaller than the variation ratio of the power. This is referred to as DOW (Direct
Over-Write).

Specifically, in a DOW PPM medium, the first power is the erase power, and the second power is the first write power. In the PWM medium, the first power is an erase power, and the second power is a first write power and a second write power.

The write power adjustment section writes and reads a test pattern by designating a part of the unused area of the disk medium as a test area. Therefore, even if the test write is performed, the medium performance of the user area is not affected.

The write power adjustment unit performs writing and reading of a test pattern using continuous partial sectors of a specific track among a plurality of tracks forming a test area. In this case, writing and reading of the test pattern may be performed by randomly specifying an appropriate sector among a plurality of tracks constituting the test area by generating random numbers. It is desirable that the sectors in the test area that have already been used are not used successively and the sectors are shifted each time.

If the write power adjustment unit cannot detect the data synchronization pattern, that is, the sync byte immediately before the user area in the track format at the time of reading the test pattern, it counts the maximum number of mismatches. That is, the sync byte is very important information for detecting the start of the data area, and if it cannot be detected, the process is immediately set as the maximum number of mismatches without counting the number of data mismatches.

When the number of mismatches from the first sector to the predetermined number of sectors is equal to or smaller than a predetermined threshold value at the time of reading the test pattern, the write power adjustment unit regards all sectors as good sectors and suspends data comparison. , A predetermined minimum value, for example, zero, is counted as the number of mismatches. For example, if the number of mismatches is 1 or less in the first sector, the number of mismatches is set to zero without comparing the subsequent sectors, and the process proceeds to the next sector.
Speed up.

When the number of mismatches exceeds a predetermined threshold value indicating a power limit by writing and reading a test pattern with the initially set write power, the write power adjustment unit increases the test power to a constant value and tries again. I do. This is a process when the limit power is higher than the start power due to the device temperature.

The write power adjusting section determines the write power to be set first from the device temperature. That is, there is a correlation that the limit power decreases when the device temperature is high and increases when the device temperature is low. Therefore, the start power is set in consideration of the correlation with the temperature.

The write power adjustment section increases the offset to be added to the recording limit power when the apparatus temperature is low and decreases it when the apparatus temperature is high, and determines the optimum write power according to the apparatus temperature. In addition, the write power adjustment unit decreases the offset to be added to the recording limit power on the inner circumference side and increases the outer circumference side when the apparatus temperature is low. Further, when the apparatus temperature is high, the inner peripheral side is made larger and the outer peripheral side is made smaller. That is, the optimum write power is determined according to the apparatus temperature and the radial position of the medium. Since the outer side and the inner side adopt the zone CAV as a medium format, they mean the inner side and the outer side determined by the zone number.

The adjustment timing judging section activates the write power adjustment in synchronization with the write command issued from the host device. That is, the adjustment timing determination unit activates the write power adjustment when the first write command is issued from the higher-level device after the activation of the device by medium loading.

This is because the medium temperature immediately after loading the medium is different from the internal temperature of the apparatus, and unless the power is adjusted after the medium temperature is balanced with the internal temperature of the apparatus, the optimum write power changes. Therefore, the write power adjustment is not performed at the time of startup, and the first write power adjustment is performed in synchronization with the issuance of the first write command in which the medium temperature is expected to be balanced with the internal temperature of the apparatus.

The adjustment timing determination unit determines an effective time for guaranteeing the validity of the write power adjustment result from the elapsed time from the start of the disk to the first write power adjustment in synchronization with the write command issued from the higher-level device. I do. When the elapsed time is shorter than a predetermined threshold time (about 2 to 3 minutes), the effective time is shortened according to the elapsed time, and when the elapsed time exceeds the threshold time, the effective time is set as the threshold time. That is, the effective time for guaranteeing the write power adjustment result is set short after startup, and the effective time is set long after the medium temperature is balanced with the internal temperature of the apparatus.

When the elapsed time from the previous write power adjustment exceeds the valid time, the adjustment timing determination unit starts the next write power adjustment.

Further, even if the elapsed time from the previous write power adjustment has not reached the effective time, the adjustment timing determination unit determines that the current internal temperature of the device relative to the internal temperature of the previous write power adjustment is within a predetermined temperature range. If it fluctuates beyond
That is, when the temperature inside the apparatus has changed significantly, the write power adjustment is started.

The write power adjusting section of the actual optical disk drive changes the write power by using the default ratio of the set write power based on the predetermined default write power when setting the test power, thereby obtaining the optimum write power. Is determined, a predetermined offset ratio is added to the default ratio of the limit power to determine the default ratio of the optimum write power.

The adjustment timing judging section activates the write power adjustment when the default write power is adjusted. Normally, write power is obtained by passing a plurality of types of drive currents corresponding to power increases through a laser diode. For example, in a PPM recording medium (read power current)
By passing + (erase power current) + (write power current), a default write power can be obtained.

For this reason, when the laser diode drive current is adjusted, the default power itself changes, and the default ratio for determining the optimum write power up to that time cannot be used. Therefore, when the adjustment of the laser diode drive current, that is, the adjustment of the default write power, is performed, the write power adjustment for determining the default ratio of the minimum write power is always performed.

[0068]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Table of Contents> 1. Device configuration Light emission adjustment 3. Optimal write power adjustment

1. FIG. 2 is a circuit block diagram of an optical disk drive which is an optical storage device of the present invention. The optical disk drive of the present invention includes a controller 10 and an enclosure 12. The controller 10 includes an MPU 14 for overall control of the optical disk drive, an interface controller 16 for exchanging commands and data with a higher-level device, a formatter 18 for performing processing necessary for reading and writing data to and from the optical disk medium, and an MPU 1.
4, a buffer memory 20 shared by the interface controller 16 and the formatter 18 is provided.

For the formatter 18, an encoder 22 and a laser diode control circuit 24 are provided as a write system, and the control output of the laser diode control circuit 24 is given to a laser diode unit 30 provided in the optical unit on the enclosure 12 side. I have. The laser diode unit 30 integrally includes a laser diode and a light receiving element for monitoring.

As an optical disk for recording and reproduction using the laser diode unit 30, that is, a rewritable MO cartridge medium, in this embodiment, 128M
B, any of 230 MB, 540 MB and 640 MB can be used. Of which 128MB and 23
For a 0 MB MO cartridge medium, pit position recording (PPM recording) for recording data in accordance with the presence or absence of a mark on the medium is adopted. The recording format of the medium is ZCAV, 128 MB is 1 zone, and 230 MB is 10 zones.

On the other hand, 540 MB and 6
For a 40 MB MO cartridge medium, pulse width recording (PWM recording) in which the edges of the mark, ie, the leading edge and the trailing edge, correspond to data is employed. Here, 640MB
The difference between the storage capacities of 540 MB and 540 MB is due to the difference in the sector capacity. When the sector capacity is 2 KB, the storage capacity becomes 640 MB.
On the other hand, at 512B, it is 540 MB. The recording format of the medium is ZCAV.
Zones and 540 MB are 18 zones.

As described above, the optical disk drive of the present invention has a capacity of 128 MB, 230 MB, 540 MB or 640 M.
It is possible to correspond to the MO cartridge of each storage capacity of B.
Therefore, when loading the MO cartridge into the optical disk drive, first read the ID part of the medium,
By recognizing the type of medium in the MPU 14 from the pit interval and notifying the type result to the formatter 18,
If the medium is a 128 MB or 230 MB medium, a formatter process corresponding to PPM recording is performed, and a 540 MB or 6 MB medium is processed.
In the case of a 40 MB medium, a formatter process according to the PWM recording is performed.

As a read system for the formatter 18, a decoder 26 and a read LSI circuit 28 are provided. For the read LSI circuit 28, the laser diode 3 by the detector 32 provided in the enclosure 12
The light receiving signal of the return light of the beam from 0
4 is input as an ID signal and an MO signal.

The read LSI circuit 28 includes an AGC circuit, a filter, a sector mark detection circuit, a synthesizer and a PL.
L and other circuit functions are provided.
A read clock and read data are created from the signals and output to the decoder 26. Further, since the zone CAV is adopted as a medium recording method by the spindle motor 40, the MPU 14
Thus, the switching control of the clock frequency corresponding to the zone is performed for the built-in synthesizer.

Here, the modulation method of the encoder 22 and the demodulation method of the decoder 26 depend on the medium type by the formatter 18, and the PPM is used for 128 MB and 230 MB.
Switching to the recording modulation and demodulation method. On the other hand, 54
The medium of 0 and 640 MB is switched to the modulation and demodulation method of PWM recording.

For the MPU 14, the enclosure 1
The detection signals of the temperature sensors 36 provided on the two sides are given. The MPU 14 controls the read, write and erase powers of the laser diode control circuit 24 to optimal values based on the environmental temperature inside the device detected by the temperature sensor 36. The MPU controls the spindle motor 40 provided on the enclosure 12 side by the driver 38.

The recording format of the MO cartridge is Z
Because of the CAV, the spindle motor 40 is rotated at a constant speed of, for example, 3600 rpm. Also MPU1
4 controls an electromagnet 44 provided on the enclosure 12 side via a driver 42. The electromagnet 44 is disposed on the side opposite to the beam irradiation side of the MO cartridge loaded in the apparatus, and supplies an external magnetic field to the medium during recording and erasing.

The DSP 15 realizes a servo function for positioning the beam from the laser diode 30 with respect to the medium. Therefore, the optical unit on the enclosure 12 side is provided with a two-segment detector 46 for receiving the beam return light from the medium, and the FES detection circuit (focus error signal detection circuit) 48 detects the focus error signal from the light reception output of the two-segment detector 46. Create E1 and DSP15
Is being entered. A TES detection circuit (tracking error signal detection circuit) 50 creates a tracking error signal E2 from the light receiving output of the two-segment detector 46,
Input to P15. The tracking error signal E2 is input to a TZC circuit (track zero crossing detection circuit) 45, which generates a track zero crossing pulse E3 to generate a DSP
15 is input.

Further, on the enclosure 12 side, a lens position sensor 52 for detecting the lens position of the objective lens for irradiating the medium with the laser beam is provided, and the lens position detection signal (LPOS) E4 is input to the DSP 15. . The DSP 15 has a driver 5 for beam positioning.
Focus actuator 5 via 4, 58, 62
6. The lens actuator 60 and the VCM 64 are controlled and driven.

Here, the outline of the enclosure in the optical disk drive is as shown in FIG. In FIG. 3, a spindle motor 40 is provided in a housing 66,
By inserting the MO cartridge 70 into the hub of the spindle motor 40 from the inlet door 68 side, the loading of the internal MO medium 72 to the hub of the spindle motor 40 is performed.

MO cartridge 70 loaded
Below the MO medium 72, there is provided a carriage 76 which is movable in a direction crossing the medium track by the VCM 64. An objective lens 80 is mounted on the carriage 76, and a beam from a semiconductor laser provided in the fixed optical system 78 is incident via a prism 82 to form a beam spot on the medium surface of the MO medium 72.

The objective lens 80 corresponds to the enclosure 1 shown in FIG.
2 is controlled by the focus actuator 56 shown in FIG. 2 in the optical axis direction, and can be moved by the lens actuator 60 in the radial direction crossing the medium track, for example, within a range of several tens of tracks. This carriage 76
2 is detected by the lens position sensor 52 of FIG. Lens position sensor 5
Reference numeral 2 denotes a neutral position in which the optical axis of the objective lens 80 is directed upward, wherein the lens position detection signal is set to 0, and a lens position detection signal corresponding to the amount of movement having different polarities for movement toward the outer side and movement toward the inner side. E4 is output.

2. FIG. 4 is a circuit block diagram of the laser diode control circuit 24 provided in the controller 10 of FIG. In FIG. 4, the laser diode unit 30 is provided with a laser diode 100 and a monitor photodiode 102 integrally. The laser diode 100 emits light by receiving a drive current I from a power supply voltage Vcc, and generates a laser beam by an optical unit and irradiates the medium surface to perform recording and reproduction.

The monitor photodiode 102 receives a part of the light from the laser diode 100 and outputs a light receiving current I0 proportional to the light emitting power of the laser diode 100. For the laser diode 100, a read power current source 104, an erase power current source 106, a first write power current source 108, and a second write power current source 11
0 are connected in parallel, and the read power current I
0, erase power current I1, first write power current I
2 and the third write power current I3.

That is, at the time of read power emission, a read power current I0 flows. At the time of erase power emission, a current (I0 + I1) obtained by adding the erase power current I1 to the read power current I0 flows. The current (I0 + I1) obtained by adding the current I2
+ I2) flows. At the time of the second write power emission, the current (I0 + I1 + I) obtained by adding the second write power current I3 to the read power current I0 and the erase power current I1.
3) flows.

For the read power current source 104, an automatic power control unit (hereinafter, referred to as “APC”) 138 is provided. For the APC 138, a target DAC register 120 and a DA converter (hereinafter referred to as "DAC")
Through 136, a specified target read power is set as the target power.

For the erase power current source 106,
An EP current DAC register 122 and a DAC 140 are provided as an EP current instruction unit. The WP1 current source 108 is provided with a WP1 current DAC register 124 and a DAC 142 as a WP1 current indicator, and the second write power current source 110 is also provided with a WP2 current DAC register 126 and a DAC 144 as a WP2 current indicator. Can be

Therefore, each of the current sources 104, 106, 10
8 and 110 are stored in the corresponding registers 120 and 12
It can be changed as appropriate by setting DAC indication values for 2, 124 and 126. Where the register,
A light emitting current source circuit is configured by the DAC and the constant current source.

APC 138 controls the monitor current im obtained from the light receiving current i0 of the photodiode 102.
Of the DAC 136 corresponding to the target read power. Therefore, a monitor current im equivalent to the read power is fed back to the APC by subtracting, from the monitor photodiode 102, the light receiving current when the light is emitted at the erase power, the first write power, and the second write power exceeding the read power.
Subtractive current sources 112, 114, and 116 are provided.

An optional subtraction current i1 is supplied to the erase power subtraction current source 112 by an EP subtraction DAC register 128 and a DAC 146 as an EP subtraction current instruction unit.
Can be set. For the first write power subtraction current source 114, W
An arbitrary subtraction current i2 can be set by the P1 subtraction DAC register 130 and the DAC 148. Second
An arbitrary subtraction current i3 can be set for the write power subtraction current source 116 by the WP2 subtraction DAC register 132 and the DAC 150 as the WP2 subtraction current instruction unit.

The monitor current im of the three subtraction current sources i1, i2, i3 in the light emission mode is as follows. At the time of read light emission; im = i0 At the time of erase light emission; im = i0-i1 At the time of light emission of the first write power; im = i0- (i1 + i2) At the time of light emission of the second write power; im = i0- (i1 + i3)

Therefore, the monitor current im is equivalent to the read power by subtracting the corresponding subtraction current from the received light current i0 regardless of whether the erase power exceeds the target read power or the first or second write power is emitted. The current flows through the monitor voltage detection resistor 118 as a current, and the APC1
It is returned to 38.

For this reason, the APC 138 controls the read power current source 104 so as to always maintain the target read power irrespective of the light emission power, whereby the specified erase power, first write power and second write power are controlled. Automatic power control is realized. As for the subtraction current, a subtraction current source circuit is constituted by the register, the DAC, and the constant current source.

The monitor voltage detected by the monitor voltage detection resistor 118 corresponding to the monitor current im is converted into digital data by an AD converter (hereinafter, referred to as “ADC”) 152 and input to the monitor ADC register 134.
The data is read out to the MPU 14 side. Therefore, the ADC 152
The monitor ADC register 134 forms a monitor current im measurement unit.

FIG. 5 shows the laser diode control circuit 2 of FIG.
4 is a PWM recording signal, a light emission current, a subtraction current, and a time chart in FIG. Now, assuming that the write data of FIG. 5B is given in synchronization with the write gate of FIG. 5A, the write data has a pulse width of FIG. 5D in synchronization with the write clock of FIG. 5C. Converted to data. Based on the pulse width data, an erase pulse is generated as shown in FIG. 5E, and a first write pulse is generated as shown in FIG. 5F. Further, the second write pulse shown in FIG. 5 (G) is generated.

The second write pulse has a number of pulses corresponding to the pulse width of the pulse width data shown in FIG. For example, the first pulse width data has a pulse width of 4 clocks, the next pulse width data has 2 clocks, and the next pulse width data has 3 clocks. Correspondingly, the second write pulse in FIG. 5G is generated following the first write pulse in FIG. 5F for two clock widths of the first data, and for the next two clock widths. There are no pulses, and one pulse is generated for the third three clock widths, and information representing the pulse width is recorded.

FIG. 5H shows FIGS. 5E, 5F and 5G.
And the light emission current and power based on the erase pulse, the first write pulse, and the second write pulse.
The PWM recording on a 40 MB overwrite medium is taken as an example. First, the read current always flows and the read power RP
Is emitting DC light. For this reason, the light-emitting current (I0 + I1) flows in synchronization with the erase pulse, thereby increasing the erase power EP. The light-emitting current I2 is added at the timing of the first write pulse, and the first write power W
The light emission current I3 is added at the timing of the second write pulse, and becomes (I0 + I1 + I3), thereby increasing the second write power WP2.

In synchronization with the emission current shown in FIG. 5H, the subtraction current shown in FIG. 5I is changed to the subtraction current sources 112 and 1 shown in FIG.
It flows to 14,116. That is, the subtraction current i1 corresponding to the increase of the erase power EP flows, the subtraction current i2 corresponding to the increase of the next first write power WP1 is added, the subtraction current (i1 + i2) flows, and further the second write The subtraction current i3 corresponding to the increase of the power WP2 is added, and the subtraction current (i1 + i3) flows.

Therefore, the monitor current im shown in FIG.
A value obtained by subtracting the subtraction current in FIG. 5H from the light-emitting current i0 corresponding to the light-emitting current and light-emitting power in FIG. 5H is always converted to a constant current equivalent to the read power even during light emission. Will be returned to

In the PWM recording of the 128 BM and 230 MB overwrite media, (RP + EP + WP1) in FIG. 5H is the erase power, and (RP + EP + WP2) is the write power. Furthermore,
(RP + EP) is emitted as assist power in synchronization with the erase pulse shown in FIG. 5 (E) so that the rise to erase power and write power can be performed at high speed.

FIG. 6 is a timing chart of the signal emission current, subtraction current, and monitor current during recording on the PPM medium. Assuming that the write data of FIG. 6B is given in synchronization with the write gate of FIG. 6A, the pit edge pulse of FIG. 6D is generated in synchronization with the write clock of FIG. 6C. You. In response to this pit edge pulse,
An erase pulse shown in FIG. 6E and a first write pulse shown in FIG. 6F are generated. In PPM recording, the second write pulse in FIG. 6G is not used.

The emission power P is obtained by causing the laser diode to emit the emission current shown in FIG. 6H by such an erase pulse and a first write pulse. In PPM recording, since the erasing power is the same as the read power RP, light emission by the read power RP by the read power current I0 is maintained even at the timing of the erase pulse. At the timing of the first write pulse, the emission current becomes (I
1 + I2) and becomes the power obtained by adding the erase power EP to the first write power WP1. FIG. 6 (I)
The subtraction current (i1 + i2) flows at the emission timing of the first write pulse. As a result, the monitor current im shown in FIG. 6 (J) is always maintained equivalent to the light receiving current of the read power.

FIG. 7 is a functional block diagram of the light emission adjustment of the present invention realized by the MPU 14 of FIG. 7, the LD light emission processing unit 160 includes a light emission coarse adjustment processing unit 16.
2. Light emission fine adjustment processing unit 164 and power setting processing unit 16
6 are provided. The light emission coarse adjustment processing unit 162 and the light emission fine adjustment processing unit 164 constitute the light emission processing unit of the present invention.

For the LD light emission processing unit 160, the type of medium loaded from outside by the registers 168, 170, 172 and 174, the mode of write or erase for access from the host device, the zone number obtained from the access track Further, the internal temperature of the apparatus is set by a temperature sensor 36 provided on the enclosure 12 side in FIG. 2, and is used for light emission adjustment and power setting processing during normal operation.

A power table storage section 180 is provided for the LD light emission processing section 160. The power table storage unit 180 uses a memory such as a DRAM included in the MPU 14 in FIG. In the power table storage unit 180,
First, as shown on the right side, the monitor ADC coefficient table 18
2. EP current DAC coefficient table 184, EP subtraction DA
C coefficient table 186, WP1 current DAC coefficient table 188, WP1 subtracted DAC coefficient table 190, WP2
A current DAC coefficient table 192 and a WP2 subtraction DAC coefficient table 194 are provided.

The monitor ADC coefficient table 182 is shown in FIG.
ADC as a power measurement for any power giving an input monitor voltage in the ADC 152 for monitoring
A relational expression based on linear approximation of the output is obtained by light emission adjustment processing, and the slope a0 and the y-axis intersection b0 of this relational expression are registered.

Tables 184, 186, 188, 1
90, 192, and 194 correspond to the DAC 14 of FIG.
The relationship between the register indicated value and an arbitrary power in each of 0, 142, 144, 146, 148, and 150 is obtained by storing the slope and the y-axis intersection of a relational expression obtained by linear approximation of a measurement result by light emission adjustment. I have.

Here, the emission current coefficient table 184,1
For 88 and 192, the relational expression of the linear approximation is represented by y = ax
Since it is set at + b, coefficients a1, a2, a3 and y-axis intersections b1, b2, b3 are registered. On the other hand, regarding the subtraction current coefficient tables 186, 190, and 194, since the relational expression y = cx + d of the linear approximation is defined, the slopes c1, c2, c3 and the y-axis intersections b1, b
2 and b3 are registered.

On the other hand, the power table storage section 180 is provided with an erase power table 196, a first write power table 198, a second write power table 200, a power ratio table 202, a temperature correction coefficient table 204, and a limit power table 206. I have. Although these tables originally store unique power values corresponding to all the zones of the medium, in the present invention, the power of all the zones is initially set when the medium is loaded. Not at least 2
Only the power values of two zones are stored.

For this reason, the light emission coarse adjustment processing section 162 obtains a relational expression that approximates each power to the zone number in a straight line by light emission adjustment using the power values of the two zones initially set in each table, and from this relational expression. The corresponding powers of all zones are calculated and registered in a table. Specifically, the ADC or DA by the light emission coarse adjustment processing unit 162
Using the adjustment result of C, the light emission fine adjustment processing unit 164 performs the measurement process by the emission adjustment using the initially set emission power of the two zones and the zone of each power in accordance with the relational expression of the linear approximation based on the measurement result. Perform the settings for each.

Further, an optimum power table 208 is provided in the power table storage section 180. In the optimum power table 208, the optimum power of each zone corresponding to the temperature in the apparatus at that time is obtained by a test light using each power adjusted after the light emission adjustment is completed. You will be registered.

In this case, the registration to the optimum power table 208 is not the optimum power itself, but a default magnification K (default ratio) obtained by dividing the obtained optimum power based on the adjustment value of each power table obtained by the light emission adjustment. be registered. Therefore, the optimal power table 20
In the power setting using the default magnification of 8, the power to be actually set can be obtained by multiplying the power adjustment value of the corresponding power table by the default magnification K. The setting of the optimum power using the optimum power table 208 is performed by the power setting processing unit 166.

The power ratio table 202 provided in the power table storage section 180 stores the second write power WP2 and the first write power WP2.
The ratio (WP2 / WP1) of the write power WP1 is stored. When the power ratio table 202 is created, the second write power table 200 becomes unnecessary, and a temperature correction coefficient table 2 for correcting the power ratio based on the temperature in the device at that time corresponding to the power ratio table 202
04 is provided.

Further, the limit power table 206 sets upper and lower limits when the corresponding default magnification K is read from the optimum power table 208 by the power setting processing unit 166 and multiplied by the adjusted default value. The upper and lower limits of the power table 206 are registered as default magnifications as in the case of the optimum power table 208. If the default magnification of the optimum power table is outside the limit magnifications Kmax and Kmin of the limit power table, the upper limit and the lower limit are determined. There is a limit.

FIG. 8 is a generic flowchart of the laser diode light emission adjustment processing by the LD light emission processing unit 160 in FIG. First, in step S1, the medium is loaded and rotated, and then in step S2, the beam is moved to, for example, the outermost non-user area of the medium by driving the carriage 76 in FIG. In this state, the process proceeds to step S3, and the light emission coarse adjustment of the laser diode is performed. At the time of coarse adjustment of the light emission of the laser diode, the focus servo is turned off, and the APC 138 is also turned off.

Next, in step S4, the focus servo and the track servo are turned on, and the APC 138 is also turned on. In step S5, the type of the medium is recognized. Recognition of the type of medium is performed by recognizing the pit interval from the read data of the track ID portion, thereby processing the medium, that is, 128 MB
Medium, 230MB medium, 540MB medium, 640
It can be recognized as an MB medium.

If the type of medium is recognized in step S5, fine adjustment is performed in step S6 by light emission of the laser diode with a plurality of powers of read, erase, and write. In this case, if the medium is a 128 MB or 230 MB medium, light emission fine adjustment according to PPM recording is performed.
If the medium is a 0 MB or 640 MB medium, the light emission fine adjustment is performed according to the PWM recording.

FIG. 9 is a generic flowchart of the LD light emission coarse adjustment in step S3 of FIG. This L
In the rough adjustment of D light emission, first, in step S1, normalization of the monitoring ADC 152 in FIG. 4 is performed. Subsequently, in step S2, the DACs 136, 140, and 1 for the emission current in FIG.
42, 144 and DAC 146, 148, 1 for subtraction current
Make 50 adjustments.

FIG. 10 shows the monitor AD in step S1 in FIG.
It is a flowchart of the normalization process of C. Monitor ADC
In the normalization process, the specified read power is set as the designated value y0 in the target DAC register 120 in FIG. 4 in step S1, and the laser diode 100 emits light at the read power. In this state, in step S2, the value x0 of the monitor ADC register 134 is read.

Next, in step S3, the target DAC register 1
The instruction value y1 = 2 mW is set to 20 and the value x1 of the monitor ADC register 134 is read in step S4. Similarly, an instruction value y2 = 4 mW is set in the target DAC register 120 in step S5, and the monitor ADC is set in step S6.
The value x2 of the register 134 is read.

By the processing in steps S1 to S6, the A power for three points of read power of 2 mW and 4 mW is obtained.
A DC 152 measurement is obtained. Therefore, step S7
From the three relational expressions, the slope a0 and the y-axis intersection b as coefficients
0 is calculated and registered in the monitor ADC coefficient table 182 of FIG. Therefore, after this normalization is completed, the measured value x obtained from the monitor ADC register 134 is thereafter substituted into the relational expression y = a0 × x + b0 to calculate the measured power y.

FIG. 11 shows a relational expression of linear approximation in the monitoring ADC normalization of FIG. That is, since the measured power on the vertical axis y is the read power, 2 mW, and 4 mW, the register value x0 on the horizontal axis obtained for each is obtained.
, X1, x2 determine three points Q0, Q1, Q2,
The coefficients a0 and b0 may be obtained from the relational expression of a straight line y = a0.times.x + b0 connecting these three points. In this case,
Although the accuracy of the relational expression is improved by obtaining three points Q0, Q1, and Q2, two points may be measured.

FIG. 12 is a flowchart of the rough emission adjustment of the DAC 140 for instructing the erasing current for erasing and the DAC 146 for instructing the subtracting current for erasing in FIG. First, in step S1, while reading the monitor ADC 134, the EP current DAC is set so that the measured power x1 becomes 2 mW.
The register value y for the register 122 is increased, and (x
1, y1).

Next, in step S2, while reading the monitor ADC register 134, the register value z of the EP subtraction DAC register 128 is increased so that the measured power becomes the read power, and (x1, z1) is obtained. Next, in step 3, while reading the monitor ADC register 134, the register value y of the EP current DAC register 122 is increased so that the measured power x2 = 4 mW, and (x2, y2) is obtained.

Further, in step S4, while reading the monitor dADC register 134, the register value z of the EP subtraction DAC register 128 is increased so that the measured power becomes the read power, and (x2, z2) is obtained. After the power measurement by the above light emission is completed, in step S5, the two points (x1, y) obtained in step S1 and step S3 are obtained.
1), (x2, y2), EP for power x
The current DAC register value y is expressed by a linear approximation relation y = a1 ·
x + b1 and the gradients a1 and y
The axis intersection point b1 is calculated.

Specifically, as shown in FIG. 13, Q1 (x
1, y1) and Q2 (x2, y2)
= A1.x + b1 and the slope a1 and the y-axis intersection point b1 are obtained as coefficients.

Next, in step S6, the two points (x1, z1) and (x2, z2) obtained in steps S2 and S4 are obtained.
Regarding 2), as shown in FIG. 14, Q3 and Q4 are set to approximate a straight line connecting the two points to obtain a relational expression z = c1 · x + d1, and the values of Q3 and Q4 are substituted into the relational expression z = c1 and y. The axis intersection d1 is calculated.

FIG. 4 calculated in step S5
7 is registered in the EP current DAC coefficient table 184 in FIG. 7. The gradient a and the y-axis intersection b of the linear approximation relational expression of the register instruction value with respect to an arbitrary power of the DAC 140 indicating the erase power emission current. Further, the slope c and the y-axis intersection point b of the linear approximation relational expression for obtaining the register value y for the DAC 146 for the subtraction current with respect to the arbitrary power calculated in step S6 are shown in the EP subtraction DAC coefficient table 18 in FIG.
6 is registered.

FIG. 15 is a flowchart of the light emission coarse adjustment of the DAC 142 for first light power emission and the DAC 148 for instructing the subtraction current in FIG. The first light power light emission coarse adjustment is basically the same as the erase light emission coarse adjustment of FIG. 12, except that the instruction power to the WP1 current DAC register 124 is two points of 4 mW and 8 mW. Different.

With the setting of the subtraction current to be the read power for the light emission of 4 mW and 8 mW in steps S1 to S4, the write power emission current is (x
Two points of (1, y1) and (x2, y2) are obtained, and two points of (x1, z1) and (x2, z2) are obtained for the subtraction current.

In step S5, an arbitrary first write power x
The slope a2 and the y-axis intersection b2 of the relational expression of the linear approximation of the register value y with respect to are calculated. The axis intersection d2 is calculated and registered in the WP1 current DAC coefficient table 188 and the WP1 subtraction DAC coefficient table 190 of FIG.

FIG. 16 is a flowchart of the second write power coarse adjustment process for the DAC 144 for instructing the current for the second write power emission in FIG. 4 and the DAC 150 for instructing the subtraction current. In the second rough write power adjustment process, first, in step S1, it is checked whether the loaded medium is a PPM recording medium. If the medium is a PPM recording medium, the process of adjusting the second write power is skipped.

Subsequently, the flow advances to step S2 to check whether or not the erase operation is performed on the PWM medium. If the erase operation is performed on the PWM medium, the second write power is not used. Therefore, in this case, the write power rough adjustment process is skipped.
Of course, the second write power rough adjustment may be always performed without determining whether the PPM medium or the PWM medium is erased. The light emission adjustment in steps S3 to S6 is the same as the erase light emission coarse adjustment in FIG. 12. In this case as well, light emission is adjusted at two points of 4 mW and 8 mW, and then the subtraction current is adjusted so as to obtain read power. ing.

In steps S7 and S8, the gradient a3 and the y-axis intersection point b3 of the linear approximation relational expression for the DAC 144 for instructing the current of the second write power emission are calculated. In step S8, the slope c3 and the y-axis intersection d3 of the linear approximation relational expression for the DAC 150 indicating the subtraction current at the time of the second write power emission are calculated, and the WP2 current DAC coefficient table 192 and WP2 in FIG.
It is registered in the subtraction coefficient table 194.

FIG. 17 shows the registered contents of each of the coefficient tables 182 to 194 in the power table storage section 180 of FIG. 7 registered by the above-described rough light emission adjustment, and these inclinations and values of the y-axis intersection are used. By forming a relational expression of linear approximation, conversion from an arbitrary monitor voltage measurement value to measurement power and conversion from arbitrary power to a current instruction value for the ADC can be realized.

FIG. 18 is a generic flowchart of the laser diode light emission fine adjustment by the light emission fine adjustment processing unit 164 of FIG. In the light emission fine adjustment processing, in step S1, the slope and the y-axis intersection are read from the already completed light emission coarse adjustment coefficient table to obtain the ADC 152 for monitor current measurement and each power required for light emission adjustment. Command DAC 140 to control the current for
144 and the DACs 146 to 150 for indicating the subtraction current are calculated.

Next, in step S2, a power table for the zone of the medium is created. Further, in step S3, a power ratio table for the zone and the temperature is created. Finally, a power limit is calculated in step S4.

FIG. 19 is a flowchart of the erase power fine adjustment performed in the process of creating the power table for the zone in step S2 of FIG. In the erasing power fine adjustment, first, in step S1, a relational expression y = a1.x + c1 relating to the current instruction DAC 140 obtained by the coarse adjustment of the erasing power, and a corresponding expression z = c1.x + d1 is set.

Next, in step S2, x1 = 3 mW is substituted into the relational expression, the corresponding current DAC register value y1 is calculated, and the laser diode 100 is driven to emit light. In this state, the subtraction DAC register also has x1 = 3 mW. By calculating the value z1 and passing the subtraction current, a state subtracted from the monitor current is created.

In the state of the light emission and the subtraction current with the power of 3 mW, the process proceeds to step S3, and the monitor AD
While reading the register value of C152 as the measurement value y, the light emission power is adjusted by the DAC 140 by changing the register value y1 for the EP current DAC register 122 so as to obtain the read power. As a result, the adjustment value (x
1, y1) can be obtained.

Next, in step S4, the light emission power is increased to 5 mW, the corresponding subtraction current is set and subtracted from the monitor current, and in step S5, the register 122 of the EP current DAC 140 is set so that the monitor ADC value y becomes the read power. The light emission current is adjusted by changing the register value y2 for. Thereby, the second point (x2, y2) is obtained.

Finally, in step S6, the two points obtained by the adjustment are substituted into the relational expression of the DAC 140 for the EP current, and the coefficient a1 of this relational expression and the y-axis intersection point b1 are calculated. The adjustment result is registered and corrected in the EP current DAC coefficient table 184 of FIG.

FIG. 20 is a flowchart of the first write power fine adjustment process. In the first write power fine adjustment process, since the two light emission currents of the erase power and the first write power are used, step S1 is performed.
Sets the relational expression of the current DAC value obtained by the coarse adjustment for the erase power and the relational expression of the subtraction DAC, and also sets the current DAC for the second write power similarly obtained by the coarse adjustment.
The relational expression of the value and the corresponding relational expression of the subtracted DAC value are set.

Next, in step S2, the first write power WP1 = 3 m for emission of the first write power of 5 mW.
W, erase power EP = 2 mW, and the light emission control is performed by calculating the respective current DC value and subtracted DAC value from the relational expression set in step S1. In this state, step S3
The monitor ADC value is read as the measured value y, and the current ADC of the first write power PW1 is set to the read power.
The light emission power is adjusted by the DAC 142 by changing the register value y1. At this point, (x1, y1) is obtained.

Next, in step S4, the first write power is set to 9
mW. The first write power of 9 mW is realized by the first write power WP = 7 mW and the erase power EP = 2 mW. Therefore, for each of 7 mW and 2 mW, the light emission control is performed by calculating the current DAC value and the subtracted DAC value for the first write power and the erase power from the relational expression of step S1. In this light emission control state, while reading the monitor ADC value y as in step S5, the WP1 current DAC value y2 is set to the read power.
To adjust the light emission power.

At this point, (x2, y2) is obtained.
Finally, in step S6, the coefficient a2 and the y-axis intersection b2 in the relational expression of the DAC 142 for indicating the first write power WP1 current at the time of emission of the second write power are calculated from the substitution expression of the relational expression of the two adjustment data. , WP1 current DAC of FIG.
It is registered in the coefficient table 188 and corrected.

FIG. 21 shows a fine adjustment process of the second write power. In step S1, a relational expression obtained by coarse adjustment of the second write power is set, and 5 m is calculated based on the relational expression.
Light is emitted at two points of W and 9 mW, and the coefficient a3 of the relational expression and the y-axis intersection point b3 are calculated from the measurement result, and the WP2 current D in FIG.
The AC coefficient table 192 will be corrected. The other points are basically the same as the first light power light emission adjustment processing of FIG.

FIG. 22 shows the power table storage unit 1 shown in FIG.
FIG. 10 is a flowchart of a zone division power table creation process for obtaining the erase power table 196, the first write power table 198, and the second write power table 200 provided in the apparatus 80 from a linear approximation relational expression for a zone number.

First, in step S1, as shown in FIG.
The zone is divided into three areas: an inner area, an intermediate area, and an outer area. Subsequently, in step S2, the values of the erase power in the erase mode in both end zones of each area, that is, the powers P11 to P16 in FIG. 23 are set. The value P2 of the first write power WP1 in the erase mode
1 to P26 are set.

Next, in step S3, the erase power and the first write power WP1 set in step S2 are linearly approximated to the zone numbers of the inner, middle and outer areas, and the slope and y-axis are obtained from the relational expression. Derive the intersection. More specifically, for example, the erase power is approximated by straight lines 210, 212, and 214 for the inner, middle, and outer regions, and the respective slopes and y-axis intersections are derived from the relational expressions of the straight lines 210, 212, and 214. I do.

In this case, the y-axis intersection points are the power values P11, P1 in the zone numbers 0, 7, and 12 at the inner peripheral end of each area.
3, P15 is used. Similarly, the first write power is linearly approximated by straight lines 216, 218, and 220, and the slope and the y-axis intersection are derived from the relational expression.

Subsequently, in step S3, for the write mode, the erase power, the first write power WP1, and the second write power WP2 at both end zones in the inner, middle, and outer regions of FIG. 23 are set. In this case, the second write power WP2 is newly set in addition to the erase power and the first write power in the erase mode, so that the second zone is provided at both end zones of the inner, middle, and outer regions in FIG. Write powers P31 to P36 are set.

Subsequently, in step S4, for each of the erase power EP, the first write power WP1, and the second write power WP2, the straight lines 210-2 in FIG.
A linear approximation is performed as shown in 26, and the slope and the y-axis intersection are derived from the relational expression.

When the above processing is completed, step S
5, the erase power EP for each of the erase mode and the write mode for the three areas of the inner circumference, the middle and the outer circumference,
First write power WP1 and second write power WP2
The table of the slope of the relational expression (excluding the erase mode) and the y-axis intersection is registered in the erase power table 19 shown in FIG.
6. This is performed for the first write power table 198 and the second write power table 200.

If the respective powers are obtained for all 18 zones, (18 zones × 3 powers = 54 powers) are required in the erase mode and the write mode, so that 108 powers need to be stored in the table. . On the other hand, in the registration of the coefficients of the relational expression of the linear approximation by the area division of the zone according to the present invention, since six coefficients need to be registered per area, (3 areas) × (6 coefficients) × (2 Mode) = 36, and the data amount of table registration can be significantly reduced.

FIG. 24 shows the registered contents of the coefficients of the relational expression obtained by the linear approximation to the erase power table 196, the first write power table 198, and the second write power table 200 of FIG. .

FIG. 25 is a flowchart of the write power ratio temperature correction process in the light emission fine adjustment process. This write power ratio temperature correction processing is applied when a power ratio table 202 for registering a power ratio with the first write power is used instead of the second write power table 200 in FIG. A temperature correction coefficient table 204 is prepared corresponding to the power ratio table 202.

First, in step S1, for example, with a 540 MB medium as an example, two different temperatures T in the innermost zone
1, T2, for example, each power ratio (WP2 / WP1) at 10 ° C. and 55 ° C. and the same different temperature T1, T2 of the outermost peripheral zone, that is, 4 of each power ratio (WP2 / WP1) at 10 ° C. and 55 ° C. Set a point. FIG. 26 shows FIG.
5, two points Q1, Q of the innermost zone in step S1
2, the horizontal axis temperature T and the vertical axis y at two points Q3 and Q4 of the outermost zone are plotted as a power ratio (WP2 / WP1).

Subsequently, in step S2, the power ratio between the temperatures T1 and T2 of the innermost peripheral zone, that is, the two points Q1 and Q2 in FIG.
Relational expression y = a1 · T + b by linear approximation of the line connecting 2
By substituting the values of Q1 and Q2 for 1, the slope a1 and the y-axis intersection b1 are calculated. Similarly, in step S3, the values of Q3 and Q4 of the outermost peripheral zone are substituted into a relational expression y = a17.T + b17 of a straight line obtained by linearly approximating both, and the slope a17 and the y-axis intersection b
Calculate 17.

Then, in step S4, the slope a1 of the innermost zone and the slope a17 of the outermost zone in the two relational expressions of FIG.
Substituting into α · N + β, the slope α and the y-axis intersection β are calculated. Similarly, in step S5, the y-axis intersection b1 of the innermost zone and the intersection b17 of the outermost zone are substituted into a linear approximation relational expression b = γ · N + δ for the zone number N, and the slope γ and the y-axis intersection δ are calculated. calculate.

Finally, in step S6, the coefficients (α, β) and the coefficients (γ, δ) using the zone number N as an index are registered in a table as shown in FIG. This FIG.
Of the power ratio table 20 shown in FIG.
2 and the temperature correction coefficient table 204.

From the power table of FIG. 27, given the zone number N and the temperature T in the apparatus at that time, the power ratio of the designated zone N can be obtained. For example, assuming that a zone number N = 2 is specified, the coefficients α02 and β02 are obtained from the table, and the slope calculation expression a = α · N +
Substituting into β, the slope a of the power ratio calculation formula is obtained.

At the same time, from the zone number N = 2 to the coefficient γ02,
δ02 is read and substituted into the intersection calculation formula b = γ · N + δ to calculate the y-axis intersection b2 of the power ratio calculation formula. By setting the calculated slope a and the y-axis intersection point b in the power ratio calculation formula, and further substituting the temperature T in the apparatus at that time,
The power ratio (WP2 / WP1) can be calculated.
The calculation of the power ratio based on the device internal temperature and the zone number N may be performed each time, or the power ratio table 2 may be calculated in advance.
02 corresponding to the zone number N, the temperature T in the apparatus at that time.
May be registered.

Further, similarly to the case where the zone shown in FIG. 23 is divided into inner, middle, and outer regions and the inclinations obtained by linear approximation are registered in a table, the inner, middle, and middle regions at the device temperature at that time are registered.
The power ratio of both end zones on the outer periphery is obtained from the contents of the table in FIG. 27. For this, as in the case of FIG. Then, this may be registered in the power ratio table 202.

FIG. 28 is a flowchart of the power limit calculation process performed in the light emission adjustment process. In the power limit calculation process, first, in step S1, the zone is divided into three regions of the inner circumference, the middle, and the outer circumference as shown in FIG.
Divided into temperature ranges. For example, 0-7 ° C, 8-15
° C, divided into eight temperature ranges of 64-71 ° C.

Subsequently, in step S2, a power upper limit Pmax and a power lower limit Pmin are set for each temperature range. FIG.
For the temperature range of 9, a power upper limit Pmax is set, and a power lower limit Pmin is set. Next, in step S3, the maximum power Pmax and the minimum power Pmin of the three areas of the inner circumference, the middle, and the outer circumference are set for each temperature range.

FIG. 29 shows an example of calculating the power limit of PWM recording. In this case, the power (RP + EP + WP2) obtained by adding the read power RP, the erase power EP, and the second write power WP2 is the maximum power and minimum power of each area. Used to set power. That is, (RP + EP +
WP2), the powers P32, P34, P36 of the outer peripheral end zones 6, 11, 17 in the inner, intermediate, and outer regions.
Is the maximum power, and the powers P31, P33, and P35 of the inner peripheral end zones 0, 7, and 12 are the minimum power Pmin.

In the case of the PPM recording medium, the maximum power and the minimum power of each area are set by the power (RP + EP + WP1) obtained by adding the read power RP, the erase power EP, and the first write power WP1. Next, in step S4, three values of the inner, middle, and outer circumferences for each temperature range are set.
A magnification Kmax with respect to the power upper limit using the maximum power Pmax of the area as a default value is calculated.

Similarly, the magnification Kmin with respect to the power lower limit with the minimum power Pmin as a default value is calculated. Finally, in step S5, a limit power table 206 shown in FIG. 7 in which default magnifications of power upper and lower limits are registered using the temperature range and the zone area for each 8 ° C. as indexes. According to such a limit power table, a corresponding default magnification Kmax of the upper power limit and a default magnification Kmin of the lower power limit are obtained from the internal temperature T ° C. and the zone number by referring to the limit power table 206. By multiplying Kmin by the power of (EP + WP2), for example, in the case of a PWM medium that gives the maximum power of the area, the upper and lower power limits can be obtained.

This is achieved by setting the upper power limits 234, 236, and 238 by linear approximation for each region in FIG.
This is substantially the same as the setting of the power lower limits 228, 230, and 232 by linear approximation. Such setting of the upper and lower limits of the power is compared with a default magnification for obtaining an optimum write power given at the time of the write operation after the light emission adjustment.

When the default magnification for obtaining the optimum write power is outside the upper power limit or lower power limit set as shown in FIG. 29, the default magnification for providing the optimum power is limited to the upper power limit or lower power limit. I do. FIG. 30 shows the registered contents of the limit power table created by the power limit calculation process of FIG.

FIG. 31 is a flowchart of the first embodiment of the present invention.
10 is another embodiment of the light power light emission coarse adjustment process. In this embodiment, the PWM by the APC 138 in FIG.
It is characterized in that drift caused in automatic light emission control of recording write power can be adjusted and compensated for in light emission coarse adjustment.

FIG. 32 shows power drift caused by light emission of write power in PWM recording. Regarding the light emission of the write power of the PWM recording, as shown in FIG.
A combination of three levels of light emission of the erase power EP, the first write power WP1, and the second write power WP2 is performed. When one light emission pulse train is completed, the light emission power is set to zero, and the process shifts to light emission of the next pulse.

A subtraction current shown in FIG. 32B is produced corresponding to the light emission power shown in FIG. 32A, and is subtracted from the received light current i0 of the monitor photodiode 102 to obtain a monitor current im corresponding to the read power P1. The automatic power control for returning to the APC 138 in FIG. 4 and maintaining the target read power is performed.

However, since the last light emission power of the PWM light emission pulse train of FIG. 32A is reduced to zero power 240, the light emission power is lower than the target read power in APC 138, and the target of APC 138 is reduced to zero power 240. The actual light emission power is insufficient for the read power.

For this reason, the APC 138 performs feedback correction to increase the power as shown by the dotted line so as to compensate for the insufficient power, and as a result, the subsequent light emission pulse train is shifted as shown by the broken line. That is,
Since the monitor current im shown in FIG. 32C always fluctuates in a direction in which the power becomes insufficient, a drift occurs in which the write power as a whole shifts toward an increase.

Therefore, in the present invention, as shown in FIG. 33 (B), the subtraction current i corresponding to the first write power WP1 which always occurs one per pulse in PWM recording.
2 is reduced so as to compensate for the power shortage in which the monitor current in FIG.

FIG. 33D shows an area 24 corresponding to the monitor current ia corresponding to the first write power WP1 with respect to the target read power RP in the monitor current of FIG. 33C.
6 and an area 248 of the time width of the monitor current ib corresponding to the insufficient power caused by setting the emission power to 0 at the end of the pulse train.

Here, in the pulse section Ta of the first write power WP1 and the section Tb in which the power is insufficient, the timing of the write clock shown in FIG. 5C and the emission power shown in FIG. 5 clocks, Tb = 1 clock, and the fixed relationship of Ta: Tb = 3: 2 is maintained.

The first write power WP1 is as shown in FIG.
5D, one pulse width data in FIG. 5D is always generated. Therefore, if the time product of the power increase region 246 and the power insufficiency region 248 viewed from the read power RP in FIG. 33D is made equal, the write power drift due to the power insufficiency as shown in FIG. 32 can be prevented.

That is, (Ta × ia) = (Tb × ib) may be set. Here, since Ta is fixed at 3 and Tb is fixed at 2, the monitor current ia of the power increasing region 246 having the same time product as the shortage region 248 is ia = ib × 2/3. In order to obtain this monitor current ia, FIG.
First write power subtraction current i in the subtraction current of (B)
2 may be set to be smaller by ia (i1-ia). That is, the corresponding value is set in the WP1 subtraction DAC register 130 of FIG. 4 at the timing of the first write power WP1 so that (i2-ia) = (i2- {ib × (2/3)}). , First write power subtraction current source 11
4 is reduced by ia (i2-ia
)And it is sufficient.

In the first write power light emission coarse adjustment in FIG. 31, in order to maintain the relationship as shown in FIG. 33D, the WP1 subtraction DAC register value z in step S2 after light emission at 4 mW in step S1. Is adjusted so that the monitor current becomes the value of the canceling power (ia) by increasing the
1, z1). Similarly, in step S3, 8 mW
WP1 subtraction D in step S4 in the state where light is emitted
Regarding the adjustment of the AC register value Z, the adjustment is made so that the monitor current ia provides the same canceling power, and (x
2, z2).

In step S5, the subtraction current is adjusted so as to be ia corresponding to the canceling power (x1,
z1), (x2, z2), based on W
The slope c2 and the y-axis intersection d2 are calculated from the P1 subtraction current DAC register and the relational expression of the linear approximation of Z, and registered in a table.

By setting the WP1 current DAC register value y using the slope c2 and the y-axis intersection point d2, FIG.
The insufficient power is compensated for by the reduction of the subtraction current at the timing of the first write power PW1 in the subtraction current of 3 (B). As a result, the monitor current ia increases beyond the target read power RP at the timing of the first write power PW1, as shown in FIG.
138 provides feedback so as to suppress this increased power.

For this reason, when the light emission pulse train ends and the power becomes zero, the APC 138 performs feedback control in a direction to suppress the power. When the power is zero, the monitor current which is much lower than the target read power RP is fed back and the power is reduced. Even if the power is increased, the power is suppressed at the previous stage, so even if the power is increased due to shortage, this will offset the shortage at the previous stage and absorb the fluctuation of the write power at the next light emission pulse train can do.

Therefore, even if the power is set to zero at the end of the pulse train of the PWM recording, drift in the direction of increasing the power by the APC 138 does not occur, and a stable write operation can be realized.

In FIG. 33, the case where the power is set to 0 at the end of the PWM power pulse train is taken as an example.
The same applies to the case where the power is reduced to P or less.

FIG. 34 shows the light emission coarse adjustment processing unit 162 of FIG.
10 is a flowchart of a write power setting process performed by a power setting processing unit 166 after all the light emission adjustments by the light emission fine adjustment processing unit 164 are completed. In the power setting process, first, in step S1, a command from a host device is interpreted to determine whether the mode is the write mode or the erase mode, and a zone number is derived from a track address.

Subsequently, in step S2, the default magnification of the optimum power given at this time is stored in the register 174.
And the temperature in the apparatus at that time obtained with the lead
The zone number obtained in 1 is read from the limit power table 206 as an index. If the default magnification of the optimal power is out of the power limit, the value is corrected to a value in which the power limit is limited. Next, step S3
Then, it is checked whether the loaded medium is a PWM recording medium. If the recording medium is a PPM recording medium, the erase power EP and the first write power WP1 are referred to in step S4 by referring to the erase power table 196 and the first write power table 198 from the designated mode and zone number of the erase or write. Is calculated.

On the other hand, if the medium is a PWM medium, the flow advances to step S5 to calculate each of the erase power EP and the first write power WP1 from the designated mode of erase or write and the zone number similarly to the case of the PPM medium. I do. Further, as for the second write power WP2, the power ratio table 2 is obtained from the internal temperature T and the zone number at that time.
02 to determine the power ratio (WP2 / WP1),
This is obtained by multiplying the already calculated first write power WP1.

When the above powers have been calculated, in step S4, the calculated erase power EP, first write power WP1, and second write power WP2 are respectively replaced by the optimum write power given at that time. The power to be set is calculated by multiplying the default magnification. Subsequently, in step S7, an instruction value of the DAC for instructing the light emission current and the optimum current is calculated from the calculated power.

The calculation of the DAC instruction value is performed by calculating the slope of the relational expression of the linear approximation from the coefficient tables 184 to 194 in FIG.
The axis intersection is read out to create a relational expression, and in step S6, the calculated power is substituted to calculate the current DAC register value and the subtraction DAC register value. Finally, in step S8, the calculated register value is set in the corresponding register of the laser diode control circuit shown in FIG. 4, and a series of power setting processing ends.

[0194] 3. Optimum Write Power Adjustment FIG. 35 is a functional block diagram of a write power adjustment function for setting the write power by the laser diode realized by the MPU 14 of the optical disk drive of FIG. 2 to an optimum value.

In FIG. 35, a write power adjustment unit 300 is configured by the MPU 14, and the write power adjustment unit 300 includes an adjustment timing determination unit 302, a test write execution unit 304, and a power table creation unit 306. The internal temperature of the device is input to the write power adjustment unit 300 by the register 308. A power table storage unit 310 is provided for the write power adjustment unit 300.

The power table storage section 310 is provided with a default erase power table 312, a default write power table 314, and a temperature correction coefficient table 316. For example, as the default erase power table 312, as shown in FIG.
The default erase power corresponding to 11 is 3.0 to 3.0.
It is stored as 4.5 mW.

The default write power table 31
4 stores default write powers = 6.0 to 11.0 mW corresponding to zone numbers i = 1 to 11, as shown in FIG. Further, as shown in FIG. 38, the temperature correction coefficient table 316 stores the temperature correction coefficients Kt = −0.1. ０．１0.10 is stored. Note that the temperature correction coefficient Kt in the temperature correction coefficient table 316 in FIG. 38 is a value when the internal temperature T = 25 ° C.

The power table storage section 310 is further provided with an erase power table 318, a first write power table 320 and a second write power table 322. Therefore, the default magnification for giving the optimum write power determined by the write power adjustment unit 300 is set to the default erase power table 31 corresponding to the zone number.
2. By multiplying by the default write power table 314, each power of the erase power table 318 and the first write power table 320 can be calculated and registered.

The second write power table 322 is determined from the default write power table 314 corresponding to the zone number since the power ratio of the second write power based on the first write power is predetermined. The second write power can be obtained by multiplying the first write power by the power ratio. Further, as for each of the erase power, the first write power, and the second write power, a temperature corrected value using the temperature correction coefficient of the temperature correction coefficient table 316 based on the internal temperature T at that time is used.

The erase power table 318 and the first write table 320 using the default value of the optimum write power determined by the write power adjusting unit 300.
The creation of the second write power table 322 is performed by the power table creation unit 306.

A power setting processing section 324 is provided for power table storage section 310. The power setting processing unit 324 receives an access from the host device after the adjustment of the optimum write power is completed, and receives a temperature in the device, a medium type, a write or erase access mode indicated by the register group 326, and a zone indicating an access track. Based on the number, power setting by light emission control of the laser diode is performed.

In this power setting, the power setting processing unit 3
Reference numeral 24 denotes an erase power table 318 in the power table storage unit 310 according to the apparatus internal temperature, the medium type, the write or erase access mode, and the zone number.
Referring to the first write power table 320, the second write power table 322, and the temperature correction coefficient table 316, based on the data retrieved from the tables, the current instruction value for each register of the laser diode control circuit 24 shown in FIG. Is calculated and output.

The adjustment timing determination section 302 provided in the write power adjustment section 300 determines the write power adjustment timing by the test write execution section 304 and starts up.
The adjustment timing determination unit 302 does not start the adjustment process of the optimum write power immediately after the medium is loaded into the optical disk drive, and the initialization process of the optical disk drive ends and the first write command is issued from the host device. Then, a test write for executing the optimum write power by the test write execution unit 304 is executed by determining this.

Once the write power adjustment processing by the test write execution section 304 is completed, the valid time of the write power adjustment result is calculated, and when the elapsed time from the end of the adjustment reaches the calculated valid time, the next time, The process of the test write execution unit 304 is started for write power adjustment. Further, when the internal temperature T input from the register 308 exceeds, for example, ± 3 ° C. until the elapsed time reaches the valid time, the write power adjustment is forcibly performed by activating the test write execution unit 304.

The test write execution unit 304 designates an arbitrary test area in the non-user area of the loaded medium, writes a predetermined test pattern on the medium while gradually decreasing the write power, and then reads out the test pattern. , The process of comparing the number of data mismatches with the original test pattern is repeated. In this test write process, the write power when the counted number of mismatches exceeds a predetermined maximum number, for example, 1000, is detected as the limit write power.

When the limit write power is detected while gradually decreasing the write power, a value obtained by adding a predetermined offset to the limit write power is determined as the optimum write power. The setting of the write power in the test write execution unit 304 is performed using a default ratio based on the write power default value at that time. Therefore, the limit write power is also detected as a default ratio indicating the limit write power, and a value obtained by adding a predetermined offset ratio to the limit ratio is determined as the default ratio of the optimum write power.

Next, the write power adjustment unit 300 shown in FIG.
The details of the adjustment processing for determining the optimum write power according to the above will be described with reference to a flowchart.

FIG. 39 shows a disk starting process when a medium is loaded into the optical disk drive of the present invention. The medium used as the optical disk drive of the present invention includes P
128 MB media and 230 MB media as PM recording media,
And 540MB and 640MB which are PWM recording media
There are four types of media. In FIG. 39, the medium is loaded in step S1, and is set on the spindle motor 40 and rotated at a constant speed as shown in FIG.

Subsequently, in a step S2, a test write request flag FL is set. Further, in step S3, the current time is initialized, and in step S4, the current in-apparatus temperature T is detected, and the processing necessary for adjusting the write power at the time of startup is ended. In the disk start-up process, in addition to the preparation process for determining the optimum write power, L shown in FIG.
According to the function of the D light emission processing unit 160, each coefficient table of the DAC for current indication provided in the laser diode control circuit and the power table for storing the default value of the emission power are created. As a result, FIG. FIG.
Then, the default erase power table 312, default write power table 314, and temperature correction coefficient table 316 shown in FIG. 38 are prepared.

FIG. 40 is a generic flowchart of the write process after the optical disk drive is started. In this write processing, the presence or absence of a test write request from a higher-level device is checked in step S1, and if there is a test write request, the process proceeds to step S4 to execute a test write. Since there is no test write request from the host device in normal time, the process proceeds to step S2, and the necessity of test write is determined.

The determination of the necessity of the test write is made by referring to FIG.
Is performed by the adjustment timing determination unit 302. When the necessity of the test write is determined in step S3, the process proceeds to step S4, where the test write execution unit 304 executes the test write and determines the optimum write power. When the optimum write power is determined, the test write request flag FL is reset in step S5.

Subsequently, the current time is updated in step S6,
The time when the optimum write power is determined by executing the test write is held. Next, in step S7, the current temperature is updated, and the temperature in the apparatus at the time when the optimum write power is determined by executing the test write is held. And step S
In step 8, if a write access is requested from the host device, the write from the host device is executed.

FIG. 41 is a flowchart of the test write necessity determination process in step S3 of FIG.
In the test write necessity determination process, first, the current time is read in step S1, and the time A from the start of the optical disk drive to the previous test write is calculated in step S2. In step S3, the time A from the start is converted into a unit time B by dividing it by a predetermined time, for example, 20 seconds.

In step S4, the unit time number B is less than 8, that is, the time A from the start to the first test write
Check if is less than 160 seconds. If it is less than 160 seconds, the process proceeds to step S5, and it is checked whether the unit time number B is less than 4, that is, the time A is less than 80 seconds.

If the time A is between 80 seconds and 160 seconds, the number of unit times B is clipped to 3, that is, the time A is clipped to 30 seconds in step S6, and the flow advances to step S7. If the time A is less than 80 seconds in step S5, the process directly proceeds to step S7. In step S7, an effective time C for guaranteeing the use of the optimum write power determined by the previous test write is calculated.

In this case, the effective time C is 20 seconds × 2 B (the number of unit times). However, the maximum value of the effective time is limited to 160 seconds. As a result, the effective time C for guaranteeing the optimum write power determined by the test write is 2B if the time A from the start to the test write is less than 160 seconds.
Is set to the time corresponding to. If it exceeds 160 seconds, the fixed effective time C is fixed to 160 seconds.

The calculation of the effective time C is varied according to the time required until the medium temperature of the medium loaded on the optical disk drive stabilizes at the internal temperature of the apparatus. That is, at the time of initialization immediately after loading the medium, there is a difference between the temperature of the medium and the inside of the apparatus, so that at this stage, the adjustment of the optimum write power based on the temperature inside the apparatus cannot be effective. Therefore, the light power is not adjusted at the time of startup.

The temperature of the loaded medium equilibrates with the temperature in the apparatus after about 1 to 2 minutes have elapsed. Therefore, the first write power adjustment is performed in synchronization with the timing at which the write command is first issued from the host device after the optical disk drive is started. Since the timing at which the write command is issued from the higher-level device after startup is various, FIG.
In steps S1 to S7, the time A from the start to the first test write is obtained, and from this time A, the effective time C for discriminating the next and subsequent test write timings is determined.

If the valid time C can be calculated in step S7, the validity determination time D is calculated in step S8 as the time obtained by adding the calculated valid time C to the previous test write time. In step S9, it is determined whether the current time has exceeded the validity determination time D. If the current time has exceeded the validity determination time D, the process proceeds to step S14, turns on the test write flag, and proceeds to the execution of the next test write.

In step S9, the current time is determined to be valid judgment time D.
If not reached, the test write flag is turned off in step S17. In step S4, the unit time B
Is 8 or more, that is, 160 seconds or more, Step S10
To check if the time obtained by subtracting the previous test write time from the current time is less than one hour. If less than one hour, the current temperature is read in step S11, and
At 12, it is checked whether the current temperature is within the range of ± 3 ° C. with respect to the previous temperature. If it is within 3 ° C., the test write flag is turned off in step S13, and no test write is performed.

If there is a temperature fluctuation exceeding the range of ± 3 ° C. with respect to the previous temperature, the test write flag is turned on in step S14, and the test write is executed. If the difference between the current time and the previous test write time is one hour or more in step S10, the test write flag is forcibly turned on in step S14 to execute the test write. Each threshold time set in the test write necessity determination processing can be appropriately determined as needed.

FIG. 42 shows the test write execution process performed in step S4 of FIG. 40, which is performed by the test write execution unit 304 of FIG. First, the temperature T in the apparatus is measured in step S1. Subsequently, in step S2, the write patterns “596595” and “FEDC,... 321” are stored in the buffer memory 20 provided in the controller 10 of FIG.
0 "for each hexadecimal test pattern. The test pattern “596595” is the worst pattern in which the error occurrence is expected to be the largest, and “FEDC,.
3210 "is the entire pattern of each hexadecimal word.

Subsequently, the flow advances to step S3 to generate a test write execution sector. The test write execution sector generates a sector address by designating a test area defined as a non-user area of the medium, as will be described later.
Next, in step S4, a default ratio WPO of the start write power WP is calculated from the temperature in the apparatus. Next, in step S5, the write power WP is calculated by multiplying the default write power ratio WPO by the default write power DWP at that time.

Next, at step S6, the default ratio WPO
Is used to calculate the erase power EP. The default erase power EP is calculated by using the erase power default ratio obtained by subtracting 1.0 from the write power default ratio WPO and multiplying by a coefficient 0.7 to 1.
This is multiplied by the default erase power DEP to calculate the erase power EP. That is, the fluctuation ratio of the erase power to the write power is suppressed.

Next, in step S7, using the calculated write power WP and erase power EP, the process proceeds to step S7.
In step 2, the two types of write patterns generated in the buffer memory are written to the test area of the medium. At this time, if the medium is 128 MB medium or 230 MB medium, PP
M recording is performed, and if the medium is a 540 MB medium or a 640 MB medium, PWM recording is performed.

When data writing is completed, step S
In step S8, the data of the test pattern is read, and
In step 9, the read pattern is compared with the original write pattern in the buffer memory, and data mismatch is counted in word units.
If the number of data mismatches is less than 1000 in step S10, since the write low power limit point has not been reached, the process proceeds to step S11, and the write power default ratio WPO
Is reduced by the predetermined value 0.05, and the process returns to step S5 again.
A test write using the default ratio WPO reduced by 0.05 is performed.

The write power default ratio W
The data write is repeated while lowering the PO. If the number of data mismatches becomes 1000 or more in step S10, it is determined that the write low power limit point has been reached, and step S1 is performed.
WPO-EDG default ratio of 25 ° C limit power at 2
Calibrate to.

That is, the value obtained by multiplying the value obtained by subtracting 25 ° C. from the current temperature by the temperature correction coefficient is added to the write low power limit point WPO-EDG determined in step S10, and calibration is performed. Next, in step S13, a predetermined offset ratio ΔWPO is added to the temperature calibration value to calculate an optimum power default ratio WPO. In step S14, each zone based on the determined optimum write power default ratio WPO is determined. Set the write power.

FIG. 43 shows a test write for gradually decreasing the test power in the execution of the test write in FIG. First, the test write is started by setting the default write power DWP at the start point 328,
The test write is performed while decreasing the start default ratio by 1.0 from 0.05 to obtain the number of mismatches.

The write power WP is equal to the lower limit write power WP.
, The number of mismatches increases, and a predetermined threshold value, for example, 1
When the number reaches 000 times, it is detected as the limit point 330.
Then, by adding a predetermined offset ratio ΔWPO to the default ratio WPO-limit corresponding to the lower limit write power WP at the limit point 330 at this time, the default ratio WP-best that gives the optimum write power WP is determined.

FIG. 44 shows an offset ratio ΔWPO added to the default ratio of the limit power in step S13 of FIG.
Shows the temperature correction coefficient Kt for the temperature T of FIG. FIG.
The temperature correction coefficient Kt for correcting the offset ratio ΔWPO with respect to the temperature T in FIG.
It is determined by a slope A, which is a coefficient of a linear approximation relation Kt = A · T + B where t = 1.0, and a y-axis intersection B.

Then, the value of the corresponding temperature coefficient Kt is obtained by substituting the temperature T in the apparatus at that time into the relational expression.
By multiplying this by the default offset ratio ΔWPO obtained at the temperature T = 25 ° C., the offset ratio ΔWPO used for calculating the optimum write power can be obtained.

FIG. 45 is a relational expression of a linear approximation of the zone correction coefficient Ki to the zone number of the offset ratio ΔWPO used in step S13 in FIG. This relational expression is determined by Ki = C ・ i + D, and its coefficients C and y
An axis intersection D is prepared. Also, since the zone correction coefficient Ki is 1.0 at the center zone number i = 6,
Default offset ratio ΔWPO in zone number 6
Is prepared.

For this reason, the zone correction coefficient Ki is obtained from the relational expression Ki = C · i + D for an arbitrary zone number i, and is multiplied by the default offset ratio ΔWPO of the zone number i to calculate the optimum write power in step S13. Can be obtained.

FIG. 46 shows the characteristic of the number of mismatches with respect to the write power WPO corresponding to the temperature inside the device in the test light of FIG. FIG. 46 (A) shows the case where the temperature inside the device is 25 ° C., FIG. 46 (B) shows the case where T = 10 ° C., and FIG. 46 (C) shows the case where T = 55 ° C. When T = 25 ° C. in FIG. 46 (A) and the temperature inside the device decreases, the characteristic curve 360 of the number of mismatches with respect to the write power changes as shown in T = 10 ° C. in FIG. 46 (B). The characteristic 364 shifts in the increasing direction.

On the contrary, as shown in FIG.
The characteristic that the write power decreases when the temperature increases to 3 ° C.
Shift to 68. For this reason, the optimum write power point changes as indicated by 362, 366, and 370 according to the temperature. If the start power of the test write is fixed to the low-power start power WPs of T = 25 ° C., for example, as shown in FIG. In the case where T = 10 ° C. as shown in FIG.
A write power lower than 30 is used as the start power.

Therefore, in the test write execution of FIG. 42, if the number of data mismatches in the first test write exceeds the threshold value 1000 of the lower power limit point, the write power default ratio ΔW in step S11.
PO is increased by a predetermined ratio, so that the start power is reduced to the limit point 33 even if the temperature is lowered.
A normal test write can be performed by moving to a power side higher than zero.

Of course, when a predetermined default value is set as the start write power, by performing temperature correction based on the temperature T in the apparatus, characteristics such as those shown in FIGS. 46A to 46C can be obtained. The optimum test light start power can be set according to the shift. Then, if the start power of the test power is still lower than the lower power limit point, an offset ratio may be added so as to increase the start power by the same processing.

FIG. 47 is a flowchart for generating the address of the test write execution sector performed in step S3 of the test write execution of FIG. The generation of the test write execution address in FIG. 47 exemplifies the generation of a random sector address. First, in step S1, the area start address of the medium is set. In the test light of the present invention, the non-user area 336 on the inner side or the non-user area 338 on the outer side with respect to the user area 334 of the medium 72 in FIG. 48 is allocated to the power adjustment area.

FIG. 49 shows a non-user area 338 on the outer side in FIG. 48. A power adjustment area 340 is set for a predetermined track range in the non-user area 338. Therefore, in step S1, the area start address of an arbitrary test write in the power adjustment area 340, that is, the track address and the sector number are set.

Next, the process proceeds to step S2, where the number of sectors for which test writing has already been completed is subtracted from the area length of one track to obtain the remaining area length. This is because the test write is not continuously performed on the sector on which the test write has been performed once. Subsequently, in step S3, the number of offset sectors is obtained by multiplying the remaining area length by a random number. As the random number, an arbitrary value in the range of 0 to 1 is generated according to a predetermined random number routine. When the number of offset sectors is obtained in this way, in step S4, the execution address is obtained by adding the number of offset sectors to the start address of the area.

FIG. 50 shows a test write by generating the random test write address shown in FIG. 47, in which three test writes 342-1, 342-2, and 342-3 are randomly performed with four sectors as one unit. I have.

FIG. 51 shows another embodiment of the test write execution sector address generation performed in step S3 of the test write execution of FIG. 42, which is characterized in that the test write execution addresses are generated sequentially. First, in step S1, the last start address of the power adjustment area is obtained by subtracting the number of tested test write sectors from the last address of the area.

Subsequently, in step S2, the previous execution address is set as the execution address. Then, step S3
Then, compare the last execution address with the last start address,
Until the previous execution address reaches the final start address, the process proceeds to step S5, and the execution address is set to the previous execution address +
Test write is performed as the number of test write sectors. If the previous execution address has exceeded the final start address, the test start is executed by setting the area start address to the execution address in step S4.

FIG. 52 shows the state of test write in the power adjustment area by successively generating test write addresses in FIG. 51.
44-2 and 344-3 are performed.

FIG. 53 is a flowchart of the data read in step S8 of FIG. In the data read after the end of the test write, the sector is first read in step S1. For this sector read, it is checked in step S2 whether or not there is an abnormal end. If abnormal termination, it is checked in step S3 whether the cause of the error is a sync byte synchronization error.

Here, as shown in the track format of FIG. 54, the sync byte 354 is important information indicating the start position of the data 356. Since reading is not possible, the process proceeds to step S5, and a pattern completely different from the test pattern is put in the read buffer in order to forcibly maximize the number of mismatches. As a result, the number of data mismatches is maximized by comparing the test patterns with different patterns in the read buffer.

For errors other than the sync byte synchronization error in step S3, other error processing is performed as needed in step S4. In step S6, it is checked whether or not the current sector is the last sector in the power adjustment area, and the processing from step S1 is repeated until the last sector is reached.
If it is the last sector, the process proceeds to the next mismatch number determination process.

FIG. 55 is a flowchart of the word-by-word counting process of the number of data mismatches in step S9 in FIG. First, in step S1, D = 0 is set in a counter D used for determination of a good quality sector, and initialization is performed. Next, in step S2, the number of mismatches for one sector is obtained by comparing the test pattern and the read pattern. In step S3, it is checked whether the number of mismatches for one sector is less than a predetermined threshold value, for example, ten.

If it is less than 10, it is determined that the sector is a good sector, and in step S4, a counter D indicating a good sector is determined.
Is incremented by one. If the number of mismatches is 10 or more, the number of mismatches is counted up. If the last sector is not determined in step S7, the process returns to step S2 again, and the next 1
The number of sector mismatches is determined by comparison processing.

If the counter D of the good sector is incremented by one in step S4, the flow advances to step S5 to determine whether or not the counter D is less than one. That is, it is checked whether the first sector in the read data is of good quality.
If D is less than 1, that is, 0, the process proceeds to step S6, where all sectors are regarded as good sectors, and the number of mismatches is set to zero.

As a result, if the first sector read by the test write is deemed to be of good quality, the subsequent sectors are shifted to the next test write without comparing the number of mismatches. As a result, the speed of the test write process can be increased and the adjustment time can be reduced.

FIG. 56 is a flowchart of the write power setting processing for each zone, that is, the power table creation processing, which is finally performed in step S14 of FIG. In the power table creation processing, a default power table for the erase power EP and the first write power WP1 for each zone is calculated from the temperature in the apparatus in step S1. Subsequently, in step S2, the write power (WP) of the zone number i
i is set, the optimum default ratio WPO obtained for the write power adjustment is multiplied by the default write power DWPi, and the temperature is further corrected to calculate the write power.

Next, in step S3, it is checked whether the medium is a PWM medium. If the medium is a PWM medium, the process proceeds to step S4, and the power ratio (WP2 / WP) of the zone number i
1) is multiplied by the write power (WP1) i corresponding to the first write power obtained in step S2 to calculate a second write power (WP2) i. Finally, in step S5, erase power (EP) i of zone number i is set.

In the calculation of the erase power, a value obtained by subtracting 1.0 from the default ratio WPO of the optimum write power obtained by the write power adjustment is multiplied by a coefficient 0.7 for suppressing the variation. Is added to 1.0 and multiplied by the default erase power DPi. Of course, the temperature is corrected based on the measured temperature at that time. FIG. 5
6, the erase power table 3 shown in the power table storage unit 310 of FIG.
18, a first write power table 320 and a second write power table 322 are created.

Then, the power corresponding to the zone number is read out for the subsequent write access from the host device, the temperature is corrected in accordance with the internal temperature at that time, and then the register of the laser diode control circuit shown in FIG. Is calculated and set, and light emission control of the laser diode 100 is performed.

[0257]

As described above, according to the present invention, the device is deteriorated by adjusting the light emission of the laser diode with two points of power that are low enough not to damage the laser diode. Light emission adjustment can be performed in a short time without any need.

Even if the number of zones increases, the light emission is adjusted by designating the power of two points, for example, by dividing into three regions, and the adjustment value at any power in all zones is obtained by linear approximation based on the adjustment result. Can be set, and light emission can be adjusted in a short time even if the number of zones increases. Furthermore, even if the number of zones changes due to a change in the format of the medium, it can be easily handled.

(Adjustment of Optimal Write Power) According to the present invention, the processing for determining the optimum write power by the test write can be appropriately performed in a short time without imposing a load on the laser diode. In other words, the adjustment process for determining the optimum write power only needs to gradually reduce the write power from the start power and detect the lower limit side limit power. Conventionally, the upper limit and lower limit two limit powers are detected. It takes only half the time as compared to Also, since high power is not required for the test light, the durability of the device can be improved without damaging the laser diode.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a block diagram of an optical disk drive according to the present invention.

FIG. 3 is an explanatory diagram of an internal structure of the apparatus in which an MO cartridge is loaded.

FIG. 4 is a block diagram of the laser diode control circuit of FIG. 2;

FIG. 5 shows a signal, a light emission current, and a signal in the PWM recording of the present invention.
Time chart of subtraction current and monitor current

FIG. 6 is a time chart of a signal, a light emission current, a subtraction current, and a monitor current in a pulse train of the PPM of the present invention.

FIG. 7 is a functional block diagram of an LD light emission processing unit realized by the MPU of FIG. 2;

8 is a generic flowchart of an LD light emission adjustment process according to FIG. 7;

FIG. 9 is a generic flowchart of an LD light emission coarse adjustment process of FIG. 8;

FIG. 10 is a flowchart of a monitor ADC normalization process of FIG. 9;

FIG. 11 is an explanatory diagram of a relational expression of linear approximation by the processing of FIG.

12 is a flowchart of an erase light emission coarse adjustment process in FIG. 9;

13 is an explanatory diagram of a relational expression of a linear approximation in the erase light emission current in FIG.

14 is an explanatory diagram of a relational expression of linear approximation in the erase subtraction current of FIG.

FIG. 15 is a flowchart of light emission coarse adjustment for the first write power in FIG. 9;

16 is a flowchart of light emission coarse adjustment for the second write power in FIG. 9;

FIG. 17 is an explanatory diagram of power table registration contents by the LD light emission coarse adjustment of FIG. 9;

FIG. 18 is a generic flowchart of the LD light emission fine adjustment processing of FIG. 8;

FIG. 19 is a flowchart of the erase power fine adjustment of FIG. 18;

20 is a flowchart of the first write power fine adjustment in FIG. 18;

FIG. 21 is a flowchart of the second write power fine adjustment of FIG. 18;

FIG. 22 is a flowchart of power table setting processing by zone area division based on the fine adjustment result.

FIG. 23 is an explanatory diagram of zone area division and straight line approximation of FIG. 22;

FIG. 24 is an explanatory diagram of power table registration contents obtained by the setting processing of FIG. 22;

FIG. 25 is a flowchart of temperature correction when the second write power is treated as a power ratio.

FIG. 26 is an explanatory diagram of a linear approximation of the power ratio with respect to the temperature in FIG. 25;

FIG. 27 is an explanatory diagram of registered contents of a power table obtained by the processing of FIG. 25;

FIG. 28 is a flowchart of a power limit calculation process of FIG. 8;

FIG. 29 is an explanatory diagram of a linear approximation in the calculation of the power limit in FIG. 28;

30 is an explanatory diagram of power table registration contents by the processing of FIG. 28.

FIG. 31 is a flowchart illustrating a drift in write power caused by automatic power control in PWM recording.

FIG. 32 is a time chart for explaining the subtraction current adjustment for compensating the drift of the write power in FIG. 31;

FIG. 33 is a time chart of the first write power light emission coarse adjustment for realizing the drift compensation of FIG. 32;

FIG. 34 is a flowchart of a power setting process using a power table whose emission has been adjusted.

FIG. 35 is a functional block diagram of an optimum write power adjustment unit realized by the MPU in FIG. 2;

FIG. 36 is an explanatory diagram of a default erase power table shown in FIG. 35;

FIG. 37 is an explanatory diagram of a default write power table in FIG. 35;

FIG. 38 is an explanatory diagram of a temperature correction coefficient table in FIG. 35;

FIG. 39 is a flowchart of a disk start-up process prior to the optimum write power adjustment of FIG. 35;

FIG. 40 is a flowchart of a write process including the optimum write power adjustment of FIG. 35;

FIG. 41 is a flowchart of test light necessity determination of FIG. 40;

FIG. 42 is a flowchart of the test write process of FIG. 40;

FIG. 43 is an explanatory diagram of detection of a limit power and setting of an optimum power in the test light of FIG. 42;

FIG. 44 is an explanatory diagram of a temperature correction coefficient for correcting the temperature of the offset ratio for obtaining the optimum power by adding to the limit power of FIG. 42;

45 is an explanatory diagram of a correction coefficient for a zone position of an offset ratio for obtaining an optimum power by adding to the limit power of FIG. 42;

FIG. 46 is an explanatory diagram showing a shift of an optimum write power depending on a temperature.

FIG. 47 is a flowchart for randomly generating a write address of the test write in FIG. 42;

FIG. 48 is an explanatory diagram of a region of a medium.

FIG. 49 is an explanatory diagram of a power adjustment area allocated to a non-user area in FIG. 48;

50 is an explanatory diagram of a test write using a random address in FIG. 47.

FIG. 51 is a flowchart for sequentially generating the write address of the test write in FIG. 42;

FIG. 52 is an explanatory diagram of a test write based on the sequential addresses in FIG. 51.

FIG. 53 is a flowchart of test data read processing by the test write in FIG. 42;

FIG. 54 is an explanatory diagram of a track format to be read from the data in FIG. 53;

FIG. 55 is a flowchart of a data mismatch counting process in the test write of FIG. 42;

FIG. 56 is a flowchart of a power table setting process using the adjustment result of the optimum write power.

FIG. 57 is an explanatory diagram of a conventional optimum write power adjustment process.

[Explanation of symbols]

10: Controller 12: Enclosure 14: MPU 15: DSP 16: Interface Controller 18: Formatter 20: Buffer Memory 22: Encoder 24: Laser Diode Control Circuit 26: Decoder 28: Read LSI Circuit 30: Laser Diode Unit 32 :: Detector 34 : Head amplifier 36: Temperature sensor 38, 42, 54, 58, 62: Driver 40: Spindle motor 44: Electromagnet 46: 2 split detector 48: FES detection circuit 50: TES detection circuit 52: Lens position sensor 56: Focus actuator 60 : Lens actuator 64: VCM (carriage actuator) 66: Housing 68: Inlet door 70: MO cartridge 72: MO medium 76: Carriage 78: Fixed light System 80: Objective lens 100: Laser diode (LD) 102: Monitor photodiode (PD) 104: Read power current source 106: Erase power current source 108: First write power current source 110: Second write power current source 112: Erase power subtraction current source 114: first write power subtraction current source 116: second write power subtraction current source 118: monitor voltage detection resistor 120: target DA register (target DAC register) 122: erase power current register (EP current DAC)
Register) 124: first write power current register (WP1 current D)
AC register) 126: Second write power current register (WP2 current D)
AC register 128: Erase power subtraction DA register (EP subtraction D)
AC register) 130: First write power subtraction DA register (WP1 subtraction DAC register) 132: Second write power subtraction DA register (WP2 subtraction DAC register) 134: Monitor ADC register 136, 140, 142, 144, 146, 148, 150: DA converter (DA)
C) 138: Automatic power control unit (APC) 152: AD converter (ADC) 160: LD light emission processing unit 162: Light emission coarse adjustment state unit 164: Light emission fine adjustment processing unit 166: Power setting processing unit 168, 170, 172 174: Register 180: Power table storage unit 182: Monitor ADC coefficient table 184: EP current DAC coefficient table 186: EP subtracted DAC coefficient table 188: WP1 current DAC coefficient table 190: WP1 subtracted DAC coefficient table 192: WP2 current DAC coefficient table 194: WP2 subtracted DAC coefficient table 196: Erase power table 198: First write power table 200: Second write power table 202: Power ratio table 204: Temperature correction coefficient table 206: Limit power table 20 8: optimal power table 300: optimal write power adjustment unit 302: test write determination unit 304: test write execution unit 306: power table creation unit 310: power table storage unit 312: default erase power table 314: default write power table 316: Temperature correction coefficient table 318: Erase power table 320: First write power table 322: Second write power table 324: Power setting processor 326: Register group 328: Start point 330: Limit point 332: Optimal point 334: User area 336 , 338: Non-user area 340: Power adjustment area 342-1 to 342-3, 344-1 to 344-3: Test write sector area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 AA01 BB10 CC02 CC16 CC18 DD03 EE01 EE05 FF21 HH01 JJ12 KK04 KK05 5D119 AA23 AA26 AA33 BA01 BB05 DA02 FA05 HA08 HA12 HA17 HA19 HA28 HA30 HA47 HA52 HA68

Claims (24)

[Claims] 1. A laser diode that emits a light beam, a predetermined test pattern is written to a medium while gradually decreasing the write power of the laser diode, and then read and compared with an original test pattern. A write power adjustment unit that counts the number of mismatches, detects the write power in which the number of mismatches exceeds a predetermined threshold as the limit write power, and determines a value obtained by adding a predetermined offset to the limit write power as the optimum write power. And an optical storage device. 2. The optical storage device according to claim 2, wherein
Further, an optical storage characterized by comprising an adjustment timing determining unit for determining the necessity of a write power adjusting process for optimizing the write power for the medium and activating the adjustment timing determining unit according to the determination result. apparatus. 3. The optical storage device according to claim 1, wherein
The write power adjustment unit has at least two write powers, a first power for erasing the recording pits of the medium and a second power for forming the recording pits. An optical storage device, wherein the first power and the second power are changed in a predetermined proportional relationship. 4. The optical storage device according to claim 1, wherein
The write power adjusting unit has at least two write powers, a first power for erasing a recording pit of a medium and a second power for forming a recording pit, and gradually reduces the write power in a stepwise manner. In this case, the variation ratio of the second power is changed to be smaller than the variation ratio of the first power. 5. The optical storage device according to claim 1, wherein:
The optical storage device, wherein the write power adjustment unit performs writing and reading of a test pattern by designating a part of the unused area of the disk medium as a test area. 6. The optical storage device according to claim 5, wherein:
The optical storage device, wherein the write power adjustment unit performs writing and reading of a test pattern using a continuous partial sector of a specific track among a plurality of tracks forming the test area. 7. The optical storage device according to claim 5, wherein:
The optical storage device, wherein the write power adjustment unit writes and reads a test pattern by randomly designating an appropriate sector in a plurality of tracks constituting the test area by random number generation. 8. The optical storage device according to claim 5, wherein:
The optical storage device, wherein the write power adjustment unit counts the maximum number of mismatches when a data synchronization pattern cannot be detected when reading a test pattern. 9. The optical storage device according to claim 5, wherein
When reading the test pattern, if the number of mismatches from the first sector to a predetermined number of sectors is equal to or smaller than a predetermined threshold when reading the test pattern, the write power adjustment unit suspends data comparison by considering all sectors as good quality sectors and An optical storage device for counting a predetermined minimum value. 10. An optical storage device according to claim 5, wherein said write power adjusting section writes and reads a test pattern with the write power set first.
An optical storage device characterized in that when the number of mismatches exceeds a predetermined threshold value indicating a power limit, the test power is increased by a certain value and a retry is performed. 11. The optical storage device according to claim 5, wherein said write power adjustment unit determines the write power to be set first from the device temperature. 12. The optical storage device according to claim 5, wherein said write power adjustment section increases an offset to be added to said recording limit power when the apparatus temperature is low and decreases when the apparatus temperature is high. An optical storage device for determining an optimum write power according to a device temperature. 13. An optical storage device according to claim 1, wherein said write power adjustment section sets an offset to be added to said recording limit power to reduce an inner peripheral side and to reduce an outer peripheral side when the apparatus temperature is low. An optical storage device, wherein the optimum write power is determined according to the device temperature and the position of the medium in the radial direction when the device temperature is high and the inner periphery is increased and the outer periphery is decreased when the device temperature is high. 14. An optical storage device according to claim 2, wherein said adjustment timing determination section activates write power adjustment in synchronization with a write command issued from a higher-level device. Storage device. 15. The optical storage device according to claim 2, wherein said adjustment timing determination unit is configured to determine a write power when a first write command is issued from said higher-level device after the device is started by loading a medium. An optical recording device for initiating adjustment. 16. The optical storage device according to claim 15, wherein the adjustment timing determination section is configured to determine an elapsed time from when the disk is started to when the first write power adjustment is performed in synchronization with a write command issued from a higher-level device. An optical storage device for determining an effective time for guaranteeing the validity of the write power adjustment result. 17. The optical storage device according to claim 16, wherein said adjustment timing determining section shortens said effective time according to said elapsed time when said elapsed time is shorter than a predetermined threshold time, and When the time exceeds the threshold time, the valid time is set as the threshold time. 18. An optical storage device according to claim 17, wherein said adjustment timing determining section is adapted to determine whether an elapsed time from a previous write power adjustment exceeds said valid time.
An optical storage device for activating a next write power adjustment. 19. An optical storage device according to claim 17, wherein said adjustment timing determination section determines whether the time elapsed since the previous write power adjustment exceeds the valid time.
An optical storage device, which starts the write power adjustment when the current device temperature fluctuates beyond a predetermined temperature range with respect to the device temperature at the time of the previous write power adjustment. 20. An optical storage device according to claim 19, wherein said write power adjusting unit uses a default ratio of the set write power based on a predetermined default write power when setting said test power. When changing the write power to determine the optimum write power,
An optical storage device, wherein a default ratio of the optimum write power is determined by adding a predetermined offset ratio to the default ratio of the limit power. 21. An optical storage device according to claim 20, wherein said adjustment timing determination unit activates a previous write power adjustment when said default write power adjustment is performed. Optical storage device. 22. A predetermined test pattern is written on a medium while gradually decreasing the write power, read out, compared with the original test pattern, and the number of data mismatches is counted. A write power adjustment unit that detects a write power exceeding a threshold value as a limit write power and determines a value obtained by adding a predetermined offset to the limit write power as an optimum write power; and A test execution unit that writes and reads a test pattern by designating a part of the user unused area as a test area;
An optical storage device comprising: 23. An optical storage device according to claim 22, wherein said write power adjusting section uses a partial sector which is continuous on a specific track among a plurality of tracks constituting said test area to form a test pattern. An optical storage device for performing writing and reading. 24. An optical storage device according to claim 22, wherein said write power adjustment section randomly designates an appropriate sector among a plurality of tracks constituting said test area by generating a random number, thereby forming a test pattern. An optical storage device for writing and reading data.