JP2004178683A - Optical disk device and recording speed control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device and a recording speed control method in which increment of light quantity required for recording is suppressed and rise of temperature of a semiconductor laser can be prevented. <P>SOLUTION: When a device receives an operation command recording data with the prescribed high recording speed (ST11), measuring operation of warp of an optical disk 11 is performed, a result of this warp measurement is compared with a setting value of warp (ST13), when it is determined that the result of warp measurement does not exceed the setting value, data is recorded with high recording speed instructed by the operation command (ST15). As the result of ST13, when it is determined that the result of warp measurement is larger than the setting value, recording speed is changed to recording speed being lower than high recording speed instructed by the operation command, and data is recorded with this changed recording speed (ST16). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical disk device that records data on an optical disk, and more particularly, to a recording speed control method for controlling a recording speed when recording data on an optical disk.
[0002]
[Prior art]
In recent years, optical disks capable of recording and reproducing data, such as CDs (Compact Discs) -R (Recordable) and DVDs (Digital Versatile Discs) -R, have been developed and put into practical use. On the other hand, an optical disc apparatus for recording and reproducing data on and from this kind of optical disc has a high-speed recording function capable of recording data at a speed several to ten and several times higher than a standard recording speed.
[0003]
This high-speed recording function is performed by the user selecting a desired speed from a plurality of preset high-speed recording speeds, such as four times, eight times, twelve times, and sixteen times the standard recording speed. Be executed.
[0004]
However, as the recording speed increases, the amount of light required for recording increases. Also, as the temperature of the laser increases, the light wavelength increases, and as the wavelength increases, the amount of light required for recording increases. Further, when recording on an inclined optical disk, the amount of light required for recording increases. (For example, refer to Patent Document 1.)
[0005]
[Patent Document 1]
JP 2000-207743 A
[0006]
[Problems to be solved by the invention]
However, in the above-described conventional technology, when the amount of light required for recording increases, the temperature of the semiconductor laser rises, further increasing the amount of light, and a vicious cycle of the increase in the amount of light and the temperature rise of the semiconductor laser occurs. There is fear.
[0007]
The present invention has been made in view of the above points, and has as its object to provide an optical disc apparatus and a recording speed control method capable of suppressing an increase in the amount of light necessary for recording and preventing a temperature rise of a semiconductor laser. I do.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an optical disc apparatus according to the present invention is directed to an optical disc apparatus that records data at a recording speed selected from a plurality of types of recording speeds on an optical disc. Measuring means, a comparing means for comparing a measured value measured by the warpage measuring means with a preset set value, and a result of comparison by the comparing means, when the measured value is larger than the set value. Changing means for changing the recording speed to a second recording speed lower than the first recording speed among the plurality of types of recording speeds.
[0009]
In order to achieve the above object, an optical disk device of the present invention is an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds. Recording power determining means for determining a first recording power by irradiating the test writing area of the optical disk with a light beam at a recording speed of 1, and setting the first recording power determined by the recording power determining means to a predetermined value. Comparing means for comparing the set value with the set value. If the result of the comparison by the comparing means indicates that the first recording power is larger than the set value, the second means having a lower speed than the first recording speed. Changing means for changing the recording speed to the recording speed.
[0010]
In order to achieve the above object, an optical disk device of the present invention is an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds. Recording means for recording the first data at a recording speed of 1 at a first recording power in an area other than the test writing area of the optical disk; Comparing the first recording power to the second recording power based on the amount of the reflected light, and comparing the second recording power by the correction unit with a preset value. When the second recording power is higher than the set value, the second recording power is changed to a second recording speed lower than the first recording speed. Additional means, characterized by having a.
[0011]
In order to achieve the above object, a recording speed control method according to the present invention is a recording speed control method for an optical disc device that records data at a recording speed selected from a plurality of types of recording speeds on an optical disc. Measuring the degree of warpage of the optical disc; and, when the measured value is greater than a preset value, a second one of the plurality of types of recording speeds that is lower than a first recording speed. Changing to a recording speed.
[0012]
In order to achieve the above object, a recording speed control method according to the present invention is a recording speed control method for an optical disc device that records data at a recording speed selected from a plurality of types of recording speeds on an optical disc. Irradiating a test beam area of the optical disc with a light beam at a first recording speed of the plurality of types of recording speeds to determine a first recording power; and determining the determined first recording power in advance. Changing the recording speed to a second recording speed lower than the first recording speed when the value is larger than the set value.
[0013]
In order to achieve the above object, a recording speed control method according to the present invention is a recording speed control method for an optical disc device that records data at a recording speed selected from a plurality of types of recording speeds on an optical disc. Recording first data at a first recording power at a first recording speed at a first recording speed out of the plurality of types of recording speeds in an area other than a test writing area of the optical disc, and at the time of this recording, Correcting the first recording power to a second recording power based on the amount of reflected light from the first data, and setting the corrected second recording power to a predetermined value. Changing the recording speed to a second recording speed lower than the first recording speed when the second recording speed is larger than the first recording speed.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating an example of an optical disk device according to an embodiment of the present invention.
[0015]
The optical disk apparatus shown in FIG. 1 is, for example, a multiple of, for example, 4 ×, 8 ×,. Data is recorded / reproduced at a recording speed selected from among various types of recording speeds.
[0016]
The optical disk 11 is driven to rotate by a spindle motor 12. The motor control circuit 13 controls the rotation speed of the spindle motor 12.
[0017]
An optical head 14 is provided facing the optical disk 11. The optical head 14 is supported so as to be movable in the tracking direction of the optical disk 11 and performs recording and reproduction of data on the optical disk 11.
[0018]
The sled motor 15 moves the optical head 14 in the tracking direction of the optical disc 11 by the rotational driving force. The thread motor control circuit 16 controls the rotation direction and the rotation speed of the thread motor 15.
[0019]
The speed detector 17 detects the moving speed of the optical head. The speed signal output from the speed detector 17 is supplied to a sled motor control circuit 16 to be used for controlling the rotation of the sled motor 15.
[0020]
The optical head 14 includes a semiconductor laser 18, and a laser control circuit 19 controls the amount of laser light emitted by the semiconductor laser.
[0021]
That is, the laser control circuit 19 controls the semiconductor 18 so that the light emission amount (recording power) becomes a value suitable for recording when data is recorded on the optical disc 11. In this case, the laser control circuit 19 controls the semiconductor laser 18 between a light emitting state and a non-light emitting state based on EFM (Eight to Fourteen Modulation) data output from the modulation circuit 20.
[0022]
Further, when the power of the optical disk device in which the optical disk 11 is loaded is turned on, or when the optical disk 11 is loaded in the optical disk device in which the power is turned on, the laser control circuit 19 uses the OPC method. The light emission amount (recording power) of the semiconductor laser 18 is controlled to have an appropriate value.
[0023]
That is, the laser control circuit 19 gradually changes the light emission amount of the semiconductor laser 18 at a selected recording speed in a test writing area (PCA: Power Calibration Area) provided on the inner peripheral side of the optical disc 11, for example. Change and record the test pattern.
[0024]
Then, the recorded test pattern on the optical disk 11 is reproduced, the recording power is adjusted based on the reproduction result, and the optimum recording power corresponding to the recording speed is determined. When recording data is input via the interface circuit 22, recording is started with the recording power determined by reproducing the test pattern.
[0025]
The modulation circuit 20 performs EFM modulation on user data supplied from the host device 21 via the interface circuit 22 and the bus line 23, and generates EFM data for recording.
[0026]
Further, the laser control circuit 19 controls the semiconductor laser 18 to emit light at a constant light emission amount for reproduction which is lower than during recording when data is reproduced from the optical disk 11.
[0027]
The light emission amount of the semiconductor laser 18 is detected by the front monitor 24 and is fed back to the laser control circuit 19. As a result, the light emission amount of the semiconductor laser 18 is maintained at a predetermined value during recording and reproduction.
[0028]
Here, the laser light emitted from the semiconductor laser 18 is focused on the optical disc 11 via the collimator lens 25, the half prism 26, and the objective lens 27.
[0029]
The laser light reflected by the optical disk 11 is received by the photodetector 30 via the objective lens 27, the half prism 26, the condenser lens 28, and the cylindrical lens 29.
[0030]
This photodetector 30 has four photoelectric conversion cells 30a, 30b, 30c, 30d. The output signals of the photoelectric conversion cells 30a to 30d are supplied to current / voltage conversion amplifiers 31a, 31b, 31c, and 31d, respectively.
[0031]
The outputs of the amplifiers 31a and 31c are added by the adder 32a. The outputs of the amplifiers 31b and 31d are added by an adder 32b. The outputs of the adders 32a and 32b are supplied to the operational amplifier 33a.
[0032]
The operational amplifier 33a generates a focus error signal FE for the objective lens 27 by subtracting the output of the adder 32a from the output of the adder 32b.
[0033]
The focus error signal FE is supplied via a focus control circuit 34 to a focus drive coil 35 for driving the objective lens 27 in the focus direction, where the focus control for the objective lens 27 is performed.
[0034]
The outputs of the amplifiers 31a and 31d are added by an adder 32c. Further, the outputs of the amplifiers 31b and 31c are added by an adder 32d. The outputs of the adders 32c and 32d are supplied to the operational amplifier 33b.
[0035]
The operational amplifier 33b generates a tracking error signal TE for the objective lens 27 by subtracting the output of the adder 32c from the output of the adder 32d.
[0036]
The tracking error signal TE is supplied to a tracking drive coil 37 for driving the objective lens 27 in the tracking direction via a tracking control circuit 36, and tracking control for the objective lens 27 is performed.
[0037]
Further, the tracking drive signal output from the tracking control circuit 36 is supplied to the sled motor control circuit 16 so that the position of the optical head 14 is controlled in accordance with the tracking control of the objective lens 27.
[0038]
The outputs of the amplifiers 32c and 32d are added by an adder 32e. The output of the adder 32e is an RF (Radio Frequency) signal corresponding to the data recorded on the optical disc 11.
[0039]
This RF signal is supplied to the data reproduction circuit 38 and the running OPC control circuit 39. The data reproduction circuit 38 demodulates the input RF signal based on the bit synchronization clock generated by the PLL (Phase Locked Loop) circuit 40.
[0040]
The data demodulated by the data reproduction circuit 38 is subjected to error correction processing by an error correction circuit 41, and then converted into an analog reproduction signal, which is used for video display and audio reproduction.
[0041]
Further, the running OPC control circuit 39 functions when performing so-called running OPC, which controls the recording power while recording user data on the optical disc 11.
[0042]
That is, the running OPC control circuit 39 detects the amount of reflected light from the amplitude level of the RF signal when executing the running OPC, and corrects the amount of light emission (recording power) of the semiconductor laser 18 to an appropriate value based on the detection result. Is controlled as follows.
[0043]
Here, the motor control circuit 13, the sled motor control circuit 16, the modulation circuit 20, the laser control circuit 19, the focus control circuit 34, the tracking control circuit 36, the data reproduction circuit 38, the running OPC control circuit 39, and the PLL circuit 40 It is controlled by a CPU (Central Processing Unit) 42 via the bus line 23.
[0044]
The CPU 42, for example, records / reproduces user data to / from the optical disc 11 (high speed) based on an operation command supplied from the host device 21 via the interface circuit 22 or from an operation unit such as a remote controller (not shown). ), Various operations of the optical disk device, such as an operation of measuring the warpage of the optical disk 11 described later, a control operation of the recording power by test writing in the OPC method, and a control operation of the recording power by the running OPC.
[0045]
In this case, the CPU 42 uses the RAM 43 as a work area and controls various operations based on a control program stored in a ROM (Read Only Memory) 44.
[0046]
The ROM 44 is also used for storing various set values required for controlling the optical disk device to various operation states.
[0047]
In the present embodiment, the ROM 44 is set as a warp set value set as a limit value of a disk warp condition and a limit value of a recording power, which requires a light amount enough to cause a temperature rise of the semiconductor laser 18 itself at the time of recording. Various setting values such as a recording power setting value are stored.
[0048]
The set value to be compared with the recording power determined by the OPC method and the set value to be compared with the recording power corrected by the running OPC method may be set separately or may be the same. .
[0049]
Next, the operation of controlling the recording speed in the optical disk device having the above configuration will be described with reference to FIGS. FIG. 2 is a flowchart showing an operation of controlling the recording speed according to the warpage of the optical disk 11 in the optical disk device.
[0050]
First, the power of the optical disk device in a state where the optical disk 11 is loaded is turned on, or the optical disk 11 is loaded in the optical disk device in the state where the power is turned on, and an operation command for recording data at a predetermined high recording speed is issued. When it is received (ST11), the warp measurement operation of the optical disk 11 is started according to an instruction of the CPU 42 based on the control program.
[0051]
For example, the optical head 14 is moved at a constant speed in the radial direction of the optical disk 11 by the sled motor 15 under the control of the sled motor control circuit 16 while the loaded optical disk 11 is irradiated with the semiconductor laser 18. Let it. Then, the radial displacement amounts of the focus error signal FE output from the focus control circuit 34 are totaled, the warpage of the optical disc 11 is calculated from the difference between the minimum displacement amount and the maximum displacement amount, and stored in the RAM 43 ( ST12).
[0052]
Next, the CPU 42 compares the warpage measurement result measured in the warpage measurement operation in ST12 with a previously stored warpage set value (ST13), and as a result of the comparison in ST13, the warpage measurement result indicates that the warpage is set. If it is determined that the value does not exceed the value (No in ST14), data recording is performed at the high recording speed specified by the operation command received in ST11 (ST15).
[0053]
As a result of the comparison in ST13, when it is determined that the warpage measurement result is larger than the set value of the warpage (Yes in ST14), the recording speed is changed to a lower recording speed than the high-speed recording speed instructed by the operation command received in ST11. I do.
[0054]
For example, if the operation command received in ST11 indicates that the recording speed is 32 ×, the recording speed is changed to the 24 × recording speed, which is one step lower, and data is recorded at the changed recording speed (ST16).
[0055]
In the above-described embodiment, the warp of the optical disk 11 loaded before data recording is measured, and the amount of warp of the optical disk is larger than a preset numerical value, and the amount of light is large enough to cause a temperature rise of the semiconductor laser 18 itself. When necessary at the time of recording, the recording speed is changed to a low value before recording, and the data is recorded, so that an unnecessary increase in the amount of light is suppressed, and the possibility of a temperature rise of the semiconductor laser 18 is avoided before recording. This has the effect of reliably recording data.
[0056]
Next, FIG. 3 is a flowchart illustrating a recording speed control operation in the optical disk device according to the recording power determined by the OPC method.
[0057]
First, the power of the optical disk device in a state where the optical disk 11 is loaded is turned on, or the optical disk 11 is loaded in the optical disk device in the state where the power is turned on, and an operation command for recording data at a predetermined high recording speed is issued. When it is received (ST21), the control operation of the recording power by trial writing in the OPC method is started according to the instruction of the CPU 42 based on the control program.
[0058]
That is, the laser control circuit 19 changes the light emission amount of the semiconductor laser 18 stepwise at the instructed recording speed in the test writing area provided on the inner peripheral side of the loaded optical disc 11 to change the test pattern. Record Then, the recorded test pattern on the optical disk 11 is reproduced, the recording power is adjusted based on the reproduction result, an appropriate recording power is determined, and stored in the RAM 43 (ST22).
[0059]
Next, the CPU 42 compares the recording power determined in ST22 with a recording power set value for each recording speed stored in advance (ST23), and as a result of the comparison in ST23, the recording power determined in ST22 is determined. If it is determined that the value does not exceed the corresponding set value (No in ST24), at the high recording speed specified by the operation command received in ST21, at the optimum recording power determined in ST22 and stored in the RAM 43, Data recording is performed (ST25).
[0060]
As a result of the comparison in ST23, if it is determined that the recording power determined in ST22 is larger than the corresponding set value (Yes in ST24), the recording is performed at a speed lower than the high-speed recording speed specified by the operation command received in ST21. The speed is changed to the speed and stored in the RAM 43.
[0061]
For example, if the operation command received in ST21 indicates that the recording speed is 32 ×, the recording speed is changed to the recording speed of 24 ×, which is one step lower, and stored in the RAM 43. Then, at the changed recording speed stored in the RAM 43, data recording is performed with the recording power corresponding to this recording speed (ST26).
[0062]
As the recording power corresponding to the changed recording speed, the optimum recording power at the changed low recording speed may be determined again by the OPC method, or may be a preset / calculated recording power.
[0063]
In the case of the above-described embodiment, the control operation of the recording power by the test writing in the OPC method on the optical disc 11 loaded before the data recording is performed, and the recording determined at the recording speed scheduled to be recorded is performed. If the power is larger than a preset value and a light amount is required at the time of recording that causes an increase in the temperature of the semiconductor laser 18 itself, the data is recorded after changing the recording speed to a low speed before recording. In addition, it is possible to suppress an unnecessary increase in the amount of light, avoid the possibility of a rise in the temperature of the semiconductor laser 18 before recording, and perform an effect of performing reliable data recording.
[0064]
Next, FIG. 4 is a flowchart showing a recording speed control operation in the optical disc device according to the recording power determined by the running OPC method.
[0065]
First, the power of the optical disk device in a state where the optical disk 11 is loaded is turned on, or the optical disk 11 is loaded in the optical disk device in the state where the power is turned on, and an operation command for recording data at a predetermined high recording speed is issued. Then, for example, test writing by the OPC method is performed, the optimum recording power is determined, and recording of data on the optical disk 11 is started.
[0066]
Along with this data recording, the amount of reflected light is detected from the amplitude level of the RF signal being recorded, and the amount of emitted light (recording power) of the semiconductor laser 18 is corrected according to the detection result (fluctuation in the amount of reflected light). (ST32).
[0067]
Next, the CPU 42 compares the recording power corrected in ST32 with the recording power set value stored in advance (ST33), and as a result of the comparison in ST33, the recording power corrected in ST32 corresponds to the corresponding set value. If it is determined that the recording power does not exceed (No in ST34), data recording is performed with the optimum recording power corrected in ST32 without changing the recording speed (ST35).
[0068]
As a result of the comparison in ST33, when it is determined that the recording power corrected in ST32 is larger than the corresponding set value (Yes in ST34), the recording speed is changed to a lower recording speed than the high recording speed during recording, and the RAM 43 is changed. To memorize.
[0069]
For example, when the recording speed during recording is 32 ×, the recording speed is changed to a 24 × recording speed which is one step lower and stored in the RAM 43. Then, data recording is performed at the changed recording speed stored in the RAM 43 and at the recording power corresponding to this recording speed (ST36).
[0070]
If the recording of the data specified by the operation command has not been completed (ST37), the process proceeds to ST32, where the recording is continued and the recording power is corrected by the running OPC method.
[0071]
In the case of the embodiment described above, the recording power corrected by the running OPC method executed during data recording is larger than a preset value, and the light intensity is large enough to cause a temperature rise of the semiconductor laser 18 itself. When recording is required, the recording speed is changed to a low value before recording, and data recording is performed to suppress an unnecessary increase in the amount of light and avoid the possibility of a temperature rise of the semiconductor laser 18 before recording. This has the effect of reliably recording data.
[0072]
The recording speed control operations described with reference to FIGS. 2 to 4 can be arbitrarily combined. Next, with reference to FIG. 5, an embodiment of a recording speed control operation combining the operations shown in FIGS. 2 to 4 will be described. In FIG. 5, the same operations as those in FIGS. 2 to 4 are denoted by the same step numbers.
[0073]
First, the power of the optical disk device in a state where the optical disk 11 is loaded is turned on, or the optical disk 11 is loaded in the optical disk device in the state where the power is turned on, and an operation command for recording data at a predetermined high recording speed is issued. When it is received (ST11), the warp measurement operation of the optical disk 11 is started according to an instruction of the CPU 42 based on the control program.
[0074]
For example, the optical head 14 is moved at a constant speed in the radial direction of the optical disk 11 by the sled motor 15 under the control of the sled motor control circuit 16 while the loaded optical disk 11 is irradiated with the semiconductor laser 18. Let it. Then, the radial displacement amounts of the focus error signal FE output from the focus control circuit 34 are totaled, the warpage of the optical disc 11 is calculated from the difference between the minimum displacement amount and the maximum displacement amount, and stored in the RAM 43 ( ST12).
[0075]
Next, the CPU 42 compares the warpage measurement result measured in the warpage measurement operation in ST12 with a previously stored warpage set value (ST13), and as a result of the comparison in ST13, the warpage measurement result indicates the set value. If it is determined that the recording speed does not exceed (No in ST14), the process proceeds to the next process without changing the high-speed recording speed specified by the operation command received in ST11.
[0076]
Also, as a result of the comparison in ST13, when it is determined that the warpage measurement result is larger than the set value (Yes in ST14), a recording speed lower than the high-speed recording speed specified by the operation command received in ST11 (for example, one step lower). (Recording speed), stored in the RAM 43, and proceeds to the next process (ST16).
[0077]
When the warpage measurement operation of the optical disk 11 is completed, the CPU 42 starts a recording power control operation by trial writing in the OPC method.
[0078]
That is, the laser control circuit 19 changes the light emission amount of the semiconductor laser 18 stepwise at the instructed recording speed in the test writing area provided on the inner peripheral side of the loaded optical disc 11 to change the test pattern. Record Then, the test pattern recorded on the optical disk 11 is reproduced, the recording power is adjusted based on the reproduction result, an appropriate recording power corresponding to the recording speed is determined, and stored in the RAM 43 (ST22).
[0079]
Then, the CPU 42 compares the recording power determined in ST22 with the recording power set value stored in advance (ST23), and as a result of the comparison in ST23, the recording power determined in ST22 does not exceed the set value. When it is determined (No in ST24), data recording is started at the high recording speed specified by the operation command received in ST21, and at the optimum recording power determined in ST22 and stored in the RAM 43 ( ST25).
[0080]
As a result of the comparison in ST23, when it is determined that the recording power determined in ST22 is larger than the set value (Yes in ST24), the recording speed lower than the high-speed recording speed specified by the operation command received in ST21 ( (For example, one step lower recording speed) and store it in the RAM 43. Then, data recording is performed at the changed recording speed stored in the RAM 43 and at the recording power corresponding to this recording speed (ST26).
[0081]
When the control operation of the recording power by the test writing in the OPC method is completed and the data recording is started, the CPU 42 detects the amount of reflected light from the amplitude level of the RF signal being recorded with this data recording. The light emission amount (recording power) of the semiconductor laser 18 is corrected according to the detection result (fluctuation in the amount of reflected light) to obtain an appropriate value (ST32).
[0082]
Then, the CPU 42 compares the recording power corrected in ST32 with the recording power set value stored in advance (ST33), and as a result of the comparison in ST33, the recording power corrected in ST32 does not exceed the set value. If it is determined (No in ST34), data recording is performed with the optimum recording power corrected in ST32 without changing the recording speed (ST35).
[0083]
As a result of the comparison in ST33, when it is determined that the recording power corrected in ST32 is larger than the set value (Yes in ST34), the recording speed is reduced to a recording speed lower than the high-speed recording speed during recording (for example, one step lower recording speed). And store it in the RAM 43. Then, data recording is performed at the changed recording speed stored in the RAM 43 and at the recording power corresponding to this recording speed (ST36).
[0084]
If the recording of the data specified by the operation command has not been completed (ST37), the process proceeds to ST32, where the recording is continued and the recording power is corrected by the running OPC method.
[0085]
As described above, in the present embodiment, the warpage of the optical disk 11 loaded before data recording is measured, and the degree of warpage of the optical disk is larger than a preset value, which causes a rise in the temperature of the semiconductor laser 18 itself. When a large amount of light is required for recording, the data is recorded after the recording speed is changed to a low speed before recording.
[0086]
When the recording speed control operation based on the warpage determination is completed, a recording power control operation is performed by a test write in the OPC method on the optical disc 11 loaded before data recording, and the recording speed determined at the recording speed instructed by the recording is performed. If the power is larger than a preset numerical value and a light amount is required at the time of recording that causes a rise in the temperature of the semiconductor laser 18 itself, the data is recorded after the recording speed is changed to a low speed before recording.
[0087]
When the control operation of the recording speed by the recording power by the test writing in the OPC method is completed, the recording power corrected by the running OPC method to be executed next during the data recording is larger than a preset value, and the semiconductor laser When a light amount that causes the temperature of the semiconductor laser 18 itself to rise is required at the time of recording, the recording speed is changed to a low speed before recording, and data recording is performed. This has the effect of avoiding the possibility of a temperature increase before recording and performing reliable data recording.
[0088]
Next, another embodiment of the recording speed control operation combining the operations shown in FIGS. 2 to 4 will be described with reference to FIG. In FIG. 6, the same operations as those in FIGS. 2 to 4 are denoted by the same step numbers.
[0089]
In the embodiment shown in FIG. 6, by lowering the recording speed by one step, the level of the light does not reach the level at which the temperature of the semiconductor laser 18 itself rises, so that any one of the set values is reached and the recording speed is reduced. In this case, comparison with the subsequent set values is not performed, which is different from the embodiment shown in FIG.
[0090]
First, the power of the optical disk device in a state where the optical disk 11 is loaded is turned on, or the optical disk 11 is loaded in the optical disk device in the state where the power is turned on, and an operation command for recording data at a predetermined high recording speed is issued. When it is received (ST11), the warp measurement operation of the optical disk 11 is started according to an instruction of the CPU 42 based on the control program.
[0091]
For example, the optical head 14 is moved at a constant speed in the radial direction of the optical disk 11 by the sled motor 15 under the control of the sled motor control circuit 16 while the loaded optical disk 11 is irradiated with the semiconductor laser 18. Let it. Then, the radial displacement amounts of the focus error signal FE output from the focus control circuit 34 are totaled, the warpage of the optical disc 11 is calculated from the difference between the minimum displacement amount and the maximum displacement amount, and stored in the RAM 43 ( ST12).
[0092]
Next, the CPU 42 compares the warpage measurement result measured in the warpage measurement operation of ST12 with a previously stored warpage set value (ST13).
[0093]
As a result of the comparison in ST13, when it is determined that the warpage measurement result is larger than the set value (Yes in ST14), a recording speed lower than the high-speed recording speed specified by the operation command received in ST11 (for example, one step lower). The recording speed is changed to (recording speed) and stored in the RAM 43, and the process proceeds to a recording process at a recording power corresponding to the low recording speed (ST41).
[0094]
As a result of the comparison in ST13, when it is determined that the warpage measurement result does not exceed the set value (No in ST14), the OPC method is performed without changing the high-speed recording speed specified by the operation command received in ST11. To start the control operation of the recording power by the test writing.
[0095]
That is, the laser control circuit 19 changes the light emission amount of the semiconductor laser 18 stepwise at the instructed recording speed in the test writing area provided on the inner peripheral side of the loaded optical disc 11 to change the test pattern. Record Then, the recorded test pattern on the optical disk 11 is reproduced, the recording power is adjusted based on the reproduction result, an appropriate recording power is determined, and stored in the RAM 43 (ST22).
[0096]
Then, the CPU 42 compares the recording power determined in ST22 with the recording power set value for each recording speed stored in advance (ST23), and as a result of the comparison in ST23, the recording power determined in ST22 is set. If it is determined that the value is greater than the value (Yes in ST24), the recording speed is changed to a recording speed lower than the high-speed recording speed specified by the operation command received in ST21 (for example, a recording speed one step lower), and stored in the RAM 43. Then, the process proceeds to the recording process with the recording power corresponding to the low recording speed (ST41).
[0097]
As a result of the comparison in ST23, when it is determined that the recording power determined in ST22 does not exceed the set value (No in ST24), the determination is made in ST22 at the high-speed recording speed instructed by the operation command received in ST21. Then, data recording is started with the optimum recording power stored in the RAM 43 (ST25).
[0098]
When the control operation of the recording power by the test writing in the OPC method is completed and the data recording is started, the CPU 42 detects the amount of reflected light from the amplitude level of the RF signal being recorded with this data recording. The light emission amount (recording power) of the semiconductor laser 18 is corrected according to the detection result (fluctuation in the amount of reflected light) to obtain an appropriate value (ST32).
[0099]
Then, the CPU 42 compares the recording power corrected in ST32 with the recording power set value stored in advance (ST33), and as a result of the comparison in ST33, the recording power corrected in ST32 does not exceed the set value. If it is determined (No in ST34), data recording is performed with the optimum recording power corrected in ST32 without changing the recording speed (ST35).
[0100]
If the recording of the data specified by the operation command has not been completed (ST37), the process proceeds to ST32, where the recording is continued and the recording power is corrected by the running OPC method.
[0101]
As a result of the comparison in ST33, when it is determined that the recording power corrected in ST32 is larger than the set value (Yes in ST34), the recording speed is reduced to a recording speed lower than the high-speed recording speed during recording (for example, one step lower recording speed). And the process is stored in the RAM 43, and the process proceeds to a recording process at a recording power corresponding to the low recording speed (ST41).
[0102]
When data recording is started, the amount of reflected light is detected from the amplitude level of the RF signal being recorded in accordance with the data recording, and the amount of light emission (recording) of the semiconductor laser 18 is determined according to the detection result (fluctuation in the amount of reflected light). Power) is corrected to an appropriate value (ST42).
[0103]
If the recording of the data specified by the operation command has not been completed (ST43), the process proceeds to ST42, where the recording is continued and the recording power is corrected by the running OPC method.
[0104]
As described above, in the present embodiment, first, the warp of the optical disc 11 loaded before data recording is measured, and the degree of the warp of the optical disc is larger than a preset value, and the temperature rise of the semiconductor laser 18 itself is measured. If an inviting amount of light is required at the time of recording, the data is recorded after the recording speed is changed to a low speed before recording.
[0105]
If the recording speed control operation based on the warpage determination is less than the set value, a comparison is made as to whether the recording power determined by the OPC method to be executed next before data recording is greater than a preset value. It is supposed to do.
[0106]
Also, if the recording speed control operation according to the OPC method is less than the set value, whether the recording power corrected by the running OPC method to be executed next during data recording is larger than a preset value. Is to be compared.
[0107]
In other words, by decreasing the recording speed by one step, it is not necessary to provide a light amount enough to cause the temperature of the semiconductor laser 18 itself to rise. Therefore, when the recording speed is changed to a low value, comparison with various set values thereafter is not performed. When proceeding to the recording operation without changing the recording speed, a comparison with various set values is executed at the time of performing OPC and running OPC.
[0108]
Therefore, it is always determined whether or not an amount of light that causes a rise in the temperature of the semiconductor laser 18 itself is required at the time of recording. If necessary, the data is recorded after changing the recording speed to a low speed before recording. In addition, it is possible to suppress an unnecessary increase in the amount of light, avoid the possibility of a rise in the temperature of the semiconductor laser 18 before recording, and perform an effect of performing reliable data recording.
[0109]
【The invention's effect】
As described above, according to the present invention, it is possible to suppress an increase in the amount of light necessary for recording and prevent a temperature rise of the semiconductor laser.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of an optical disc device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a control operation of a recording speed according to a warp of the optical disk 11 in the optical disk device.
FIG. 3 is a flowchart showing a control operation of a recording speed according to a recording power determined by the OPC method in the optical disc device.
FIG. 4 is a flowchart showing a control operation of a recording speed according to a recording power determined by a running OPC method in the optical disc device.
FIG. 5 is a flowchart for explaining an embodiment of a recording speed control operation in which the operations shown in FIGS. 2 to 4 are combined;
FIG. 6 is a flowchart for explaining another embodiment of the recording speed control operation obtained by combining the operations shown in FIGS. 2 to 4;
[Explanation of symbols]
11 Optical disk
12 Spindle motor
13 Motor control circuit
14 Optical head
15 Thread motor
16 Thread motor control circuit
17 Speed detector
18 Semiconductor laser
19 Laser control circuit
20 Modulation circuit
22 Interface Circuit
23 bus line
24 Front monitor
25 Collimator lens
26 Half Prism
27 Objective lens
28 condenser lens
30 Photodetector
30a, 30b, 30c, 30d photoelectric conversion cell
31a, 31b, 31c, 31d Amplifier
32a, 32b adder
33a, 33b Operational amplifier
34 Focus Control Circuit
35 Focus drive coil
36 Tracking control circuit
37 Tracking drive coil
38 Data Recovery Circuit
39 Running OPC control circuit
42 CPU

Claims (16)

In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Warpage measuring means for measuring the degree of warpage of the optical disc,
Comparing means for comparing a measured value measured by the warpage measuring means with a preset set value;
Changing means for changing to a second recording speed lower than a first recording speed among the plurality of types of recording speeds when the measured value is larger than the set value as a result of the comparison by the comparing device; ,
An optical disk device comprising: If the result of comparison by the comparing means is that the measured value is greater than the set value, data recording is performed at the second recording speed changed by the changing means, and the result of comparison by the comparing means 2. The optical disk device according to claim 1, further comprising control means for controlling to execute data recording at the first recording speed when the value is smaller than the set value. In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Recording power determining means for irradiating a test beam area of the optical disc with a light beam at a first recording speed of the plurality of types of recording speeds to determine a first recording power;
Comparing means for comparing the first recording power determined by the recording power determining means with a preset setting value;
Changing means for changing to a second recording speed lower than the first recording speed when the first recording power is higher than the set value as a result of the comparison by the comparing means;
An optical disk device comprising: As a result of the comparison by the comparing means, when the first recording power is higher than the set value, the second recording speed changed by the changing means using the second recording power lower than the set value When the first recording power is smaller than the set value as a result of the comparison by the comparing means, the data recording is performed at the first recording speed using the first recording power. 4. The optical disk apparatus according to claim 3, further comprising control means for performing control. In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Recording means for recording first data at a first recording power in a region other than the test writing region of the optical disc at a first recording speed of the plurality of types of recording speeds;
Correction means for correcting the first recording power to a second recording power based on the amount of reflected light from the recorded first data during recording by the recording means;
Comparing means for comparing the second recording power by the correcting means with a preset set value;
Changing means for changing to a second recording speed lower than the first recording speed when the second recording power is higher than the set value as a result of the comparison by the comparing means;
An optical disk device comprising: As a result of the comparison by the comparing means, when the second recording power is higher than the set value, the second recording speed changed by the changing means using the third recording power lower than the set value When the second recording power is smaller than the set value as a result of the comparison by the comparing means, the data recording is performed at the first recording speed using the second recording power. 6. The optical disk device according to claim 5, further comprising control means for controlling execution. In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Warpage measuring means for measuring the degree of warpage of the optical disc,
First comparing means for comparing a measured value measured by the warpage measuring means with a preset warpage setting value;
As a result of the comparison by the first comparing means, when the measured value is smaller than the set value of the warpage, the light beam is applied to the test writing area of the optical disc at the first recording speed among the plurality of recording speeds. Recording power determining means for irradiating to determine a first recording power;
Second comparing means for comparing the first recording power determined by the recording power determining means with a preset recording power set value;
As a result of the comparison by the first comparing means, when the measured value is larger than the set value of the warpage, or as a result of the comparison by the second comparing means, the first recording power is more than the set value of the recording power. Changing the recording speed to a second recording speed lower than the first recording speed,
An optical disk device comprising: In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Warpage measuring means for measuring the degree of warpage of the optical disc,
First comparing means for comparing a measured value measured by the warpage measuring means with a preset warpage setting value;
As a result of the comparison by the first comparing means, when the measured value is smaller than the set value of the warpage, the light beam is applied to the test writing area of the optical disc at the first recording speed among the plurality of recording speeds. Recording power determining means for irradiating to determine a first recording power;
Second comparing means for comparing the first recording power determined by the recording power determining means with a preset first recording power set value;
As a result of the comparison by the second comparing means, when the first recording power is smaller than the first recording power set value, the first recording power is applied to an area other than the test writing area of the optical disc at the first recording speed. Recording means for recording first data at the first recording power;
Correction means for correcting the first recording power to a second recording power based on the amount of reflected light from the recorded first data during recording by the recording means;
Third comparison means for comparing the second recording power by the correction means with a preset second recording power set value,
As a result of the comparison by the first comparing means, when the measured value is larger than the set value of the warpage, or as a result of the comparison by the second comparing means, the first recording power is equal to the first recording power. If the second recording power is larger than the set value, or if the result of the comparison by the third comparing means is that the second recording power is larger than the second recording power set value, the speed is lower than the first recording speed. Changing means for changing to the second recording speed;
An optical disk device comprising: The method according to claim 1, wherein the changing unit changes the recording speed from a plurality of types of recording speeds to a second recording speed which is one step lower than the first recording speed. An optical disk device according to claim 7. In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Warpage measuring means for measuring the degree of warpage of the optical disc,
First comparing means for comparing a measured value measured by the warpage measuring means with a preset warpage setting value;
As a result of the comparison by the first comparing means, when the measured value is larger than the set value of the warpage, a first changing means for changing to a second recording speed lower than the first recording speed. When,
If the measured value is smaller than the set value of the warpage at the second recording speed and as a result of the comparison by the first comparing means when changed by the first changing means, Recording power determining means for determining a first recording power by irradiating a light beam to a test writing area of the optical disk at a speed;
Second comparing means for comparing the first recording power determined by the recording power determining means with a preset recording power set value;
A second changing unit that changes the recording speed to a lower recording speed when the first recording power is greater than the recording power set value as a result of the comparison by the second comparing unit;
An optical disk device comprising: In an optical disk device that records data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Warpage measuring means for measuring the degree of warpage of the optical disc,
First comparing means for comparing a measured value measured by the warpage measuring means with a preset warpage setting value;
As a result of the comparison by the first comparing means, when the measured value is larger than the set value of the warpage, the setting is changed to a recording speed lower than the first recording speed among the plurality of types of recording speeds. First changing means for performing
Recording power determining means for irradiating a test beam area of the optical disc with a light beam at a set recording speed among the plurality of types of recording speeds to determine a first recording power;
Second comparing means for comparing the first recording power determined by the recording power determining means with a preset first recording power set value;
As a result of the comparison by the second comparing means, when the first recording power is higher than the first recording power set value, the setting is changed to a recording speed lower than the set recording speed. 2 changing means,
Recording means for recording first data in an area other than the test writing area of the optical disc at a recording power set corresponding to the set recording speed among the plurality of types of recording speeds;
Correction means for correcting the recording power corresponding to the recording speed based on the amount of reflected light from the recorded first data during recording by the recording means;
A third comparing means for comparing the recording power corrected by the correcting means with a preset second recording power set value;
As a result of the comparison by the third comparing means, if the corrected recording power is larger than the second recording power set value, the setting is changed to a recording speed lower than the set recording speed. 3 changing means,
An optical disk device comprising: In a recording speed control method in an optical disk device for recording data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Measuring the degree of warpage of the optical disc;
When the measured value is larger than a preset value, changing the recording speed to a second recording speed lower than the first recording speed among the plurality of types of recording speeds;
A recording speed control method, comprising: In a recording speed control method in an optical disk device for recording data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Irradiating a test writing area of the optical disc with a light beam at a first recording speed of the plurality of types of recording speeds to determine a first recording power;
Changing the second recording speed lower than the first recording speed when the determined first recording power is larger than a preset value;
A recording speed control method, comprising: In a recording speed control method in an optical disk device for recording data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Recording first data with a first recording power in an area other than a test writing area of the optical disc at a first recording speed of the plurality of types of recording speeds;
At the time of this recording, a step of correcting the first recording power to a second recording power based on the amount of reflected light from the recorded first data;
When the corrected second recording power is larger than a preset value, changing to a second recording speed lower than the first recording speed;
A recording speed control method, comprising: In a recording speed control method in an optical disk device for recording data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Measuring the degree of warpage of the optical disc;
When the measured value is smaller than a preset warp set value, a light beam is applied to a test writing area of the optical disc at a first recording speed among the plurality of types of recording speeds to perform first recording. Determining power;
If the measured value is larger than the warpage set value, or if the first recording power is larger than a preset recording power set value, a second recording speed lower than the first recording speed is set. Changing to a recording speed of 2;
Performing data recording at the changed second recording speed;
A recording speed control method, comprising: In a recording speed control method in an optical disk device for recording data on an optical disk at a recording speed selected from a plurality of types of recording speeds,
Measuring the degree of warpage of the optical disc;
When the measured value is smaller than a preset warp set value, a light beam is applied to a test writing area of the optical disc at a first recording speed among the plurality of types of recording speeds to perform first recording. Determining power;
When the determined first recording power is smaller than a preset first recording power set value, the first recording power is applied to an area other than the test writing area of the optical disc at the first recording speed. Recording the first data;
At the time of this recording, a step of correcting the first recording power to a second recording power based on the amount of reflected light from the recorded first data;
When the measured value is greater than the warpage setting value, when the first recording power is greater than the first recording power setting value, or when the second recording power is a predetermined second recording power. Changing the recording power to a second recording speed lower than the first recording speed when the recording power is larger than the second recording power setting value;
Performing data recording at the changed second recording speed;
A recording speed control method, comprising:

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