JP3843000B2 - Optical disk recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disc recording apparatus for writing a signal on a recordable optical disc such as a CD - RW.
[0002]
[Prior art]
Conventionally, CD (compact disc) has been widely used as one of recording media, and CD - RW, which is a CD capable of rewriting signals, has also been widely used. The CD - the RW, performs test writing in a plurality of laser output varies stepwise test writing area, reads it, but to determine the laser output at the time of writing, before the trial writing, a write target The ε value is adjusted according to CD - RW. The ε values, the power PE0 during erase, the ratio of the power PW0 during a write (PE0 / PW0), already has a unique value in the disk. Therefore, in the optical disk recording apparatus, first, the ε value is read from the CD - RW disc, and the laser output is set so as to be the ε value.
[0003]
For this purpose, first, the laser output from the optical pickup is set to erase power, the focus is turned off to make it defocused, the CD - RW disc on the turntable is irradiated, and the front monitor diode due to the reflected light at this time The output of (FMD) is output as a DC voltage value by a low-pass filter. Then, the control value of the voltage value VRDC to the low-pass filter output value is determined laser power at the time of erasing to a predetermined value, the resistance value of the digital potentiometer having a power supply voltage Vcc (+ 5V) voltage across Then, the laser output at the time of writing (write power: corresponding to VWDC) was adjusted, and thereby the ε value was adjusted.
[0004]
[Problems to be solved by the invention]
In such conventional adjustment of the ε value, since the focus is turned off at the time of adjustment, there is a problem that it takes time to make an adjustment to turn on the focus thereafter. In addition, although the focus is off, the laser is irradiated to the disk, so that the disk may be adversely affected. Furthermore, is adjusted by the output of the low-pass filter, low detection accuracy of the laser output, there is a problem the adjustment accuracy is low.
[0005]
The present invention has been made in view of the above problems, and an object thereof is to provide an optical disk recording apparatus capable of effectively adjusting the ε value.
[0006]
[Means for Solving the Problems]
An optical disk recording apparatus according to claim 1 of the present invention is an optical disk recording apparatus for writing a signal to an optical disk, which is used as a signal writing laser output, a command value VRDC for laser output at the time of erasing, and have twofold command value VWDC for laser output, a storage means for storing digital data corresponding thereto, the command value VRDC and laser during the writing of the laser output when the erase stored in the storage means and the digital data corresponding to the command value VWDC for output, based on the ε value set in accordance with the optical disk to be recorded, the command value VRDC and the laser output at the time of the writing of the laser output when the erase have a, and adjusting means for adjusting the command value VWDC for, in the pre-shipment, the toilets The digital data corresponding to the command value VRDC for the laser output at the time of writing and the command value VWDC for the laser output at the time of writing are the command value VRDC about the laser output at the time of erasing and the laser output at the time of writing. Data corresponding to two laser output values set with a representative laser output value corresponding to the command value VWDC of the two, and corresponding to two laser output values set with the representative laser output value Command value VRDC for the laser output at the time of erasing and the laser at the time of writing based on the digital data including the data to be recorded and the ε value obtained from the optical disc and set according to the optical disc to be recorded A command value VWDC for output is set and adjusted .
[0007]
With the above configuration, the ε value set according to the optical disc to be recorded can be adjusted based on the data stored in the storage means, and adjustment with a digital potentiometer or the like is not necessary. In the adjustment using the digital potentiometer, the laser output is adjusted by irradiating the laser with the focus off, and it takes a long time to recover and the disk may be adversely affected. Can be resolved. Furthermore, since the output setting is performed based on the digital data, the ε value is adjusted with high accuracy.
Further, by using two values sandwiching a normally used laser output value as a value to be stored, a highly accurate setting is performed.
[0008]
The optical disk recording apparatus according to claim 2 is the optical disk recording apparatus according to claim 1, wherein the digital data corresponding to the VRDC is defined as Y1, Y2, and the digital data corresponding to the VWDC is defined as Y3, Y4. The laser output PE0 at the time of erasing is defined as X1, X2, the laser output PW0 at the time of writing is defined as X3, X4, the PE0 necessary for γ adjustment is defined as XE, the voltage to be set in the VRDC is defined as YE, and the VWDC When setting the voltage to be set to YW,
The D / A conversion value of the VRDC corresponding to the XE is
YE = Y1 + ((Y2-Y1) / (X2-X1)) * (XE-X1)
Is obtained at
The laser output value XW of the VWDC corresponding to the XE is
XW = XE / ε
Is obtained at
The D / A conversion value of the VWDC corresponding to the XW is
YW = Y3 + ((Y4-Y3) / (X4-X3)) * (XW-X3)
It is acquired by .
[0009]
The optical disk recording apparatus according to claim 3 is the optical disk recording apparatus according to claim 1 or 2, wherein the ε value set according to the optical disk to be recorded is a laser output PE0 during erasing and a laser during writing. A ratio PE0 / PW0 with respect to the output PW0 is used.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
It will be described with reference to the drawings with an embodiment of the optical disk recording apparatus according to the present invention below.
[0011]
FIG. 1 is a block diagram showing an embodiment of the configuration of an optical disk recording apparatus according to the present invention .
Optical disc 10 is rotated at a predetermined rotational speed by a spindle motor 12. The optical pickup 14 irradiates the optical disk 10 with laser light and receives the reflected light. The optical pickup 14 supplies a reception signal corresponding to light reception to the readout circuit 16. The read circuit 16 restores read data from the received signal and writes it in the DRAM 18. The read data in the DRAM 18 is output as appropriate. For example, it is supplied to a computer via an interface and a communication bus. The optical pickup 14 has a front monitor diode (FMD) that detects the intensity of the reflected light.
[0012]
The DRAM 18 stores write data supplied from a computer or the like via a communication bus or interface. Writing the data in the DRAM18 is read by the write circuit 20, is converted by the laser control unit 28 to a predetermined write signal, it is supplied to the optical pickup 14. The optical pickup 14 emits light corresponding to the write signal, and writing to the optical disc 10 is thereby performed.
[0013]
Further, a read signal from the optical pickup 14 obtained in the read circuit 16 is also supplied to the rotation control circuit 22. The rotation control circuit 22 detects the number of rotations of the optical disc 10 based on the read signal. A rotation control circuit 22, CPU 24 and the signal is supplied for the target rotational speed from the rotation control circuit 22 compares the detected rotational speed of the optical disk 10 and the target rotational speed, the motor of the motor rotation control signal This is supplied to the driver 26. The motor driver 26 controls the spindle motor 12 in accordance with the motor rotation control signal, whereby the rotation speed of the optical disc 10 is controlled to the target rotation speed.
[0014]
Further, a signal about the intensity of light received by the optical pickup 14 is supplied to the laser control unit 28, and the laser control unit 28 controls the laser output in the optical pickup 14.
[0015]
Here, when a signal is written on the optical disc 10, a predetermined signal is written to the test writing area prior to signal recording, and this is read to detect the optimum laser output and set the laser output. Further, when the optical disc 10 is a CD-RW, the ε value is adjusted prior to trial writing. The ε values, the laser output PE0 during erase in CD-RW, it is the ratio of the laser output PW0 of signal writing (PE0 / PW0), which will be set in the following manner.
[0016]
Here, the setting of this ε value will be described. First, the laser output is controlled by VRDC and VWDC which are voltage signals supplied to the laser oscillator of the optical pickup 14. That is, as shown in FIG. 2, in the output from the laser control unit 28, VRDC is output by the PE0 control signal at the time of signal erasing (erasing), and the PW0 control signal at the time of signal writing (at writing). Depending on the state, a voltage that rises and falls between VWDC and GND is output. In accordance with this voltage, a laser is output, and signal erasure and writing are performed on the CD-RW disc.
[0017]
Here, FIG. 3 shows the laser control unit 2 8, the configuration for the laser output. The VWDC generation unit 30 and the VRDC generation unit 32 generate VWDC and VRDC, respectively, in accordance with instructions from the CPU 24. The write circuit 20 generates a PW0 control signal and a PE0 control signal according to the write data. The PW0 control signal and the PE0 control signal control ON / OFF of switches 36 and 38 provided in a path from the VWDC generation circuit 30 and the VRDC generation circuit 32 to the laser driver 34. Therefore, the signal supplied to the laser driver 34 is controlled according to the write data. Then, the laser driver 34, VWDC supplied, on the basis of VRDC, controls the light emission by the laser diode 40. The output of the laser diode 40 is detected by a front monitor diode (FMD) 42 and supplied to a VWDC generation circuit 30 and a VRDC generation circuit 32. The VWDC generation circuit 30 and the VRDC generation circuit 32 output VWDC and VRDC. Is controlled according to the detection value of the FMD 42.
[0018]
The VWDC generation circuit 30, the VRDC generation circuit 32, and the switches 36 and 38 are provided in the laser control unit 28, and the laser driver 34, the laser diode 40, and the FMD 42 are provided in the optical pickup 14.
[0019]
In the present embodiment, VRDC and VWDC data corresponding to a predetermined laser output are stored in the register 28a. At the stage of pre-shipment in the factory, it is written the data for the VRDC and VWDC in the register 28a. For example, for a VRDC and VWDC corresponding to a typical two laser output value, and stores the digital data obtained by converting the A / D converter to the register 28a. Laser output also corresponding VRDC is generally approximately 7 mW, a typical two points, and 6 mW, select and 8 mW, and stores the digital values of VRDC to register 28a corresponding thereto. Further, the laser output also corresponding VWDC is generally approximately 14 mW, as a typical two points, and 12 mW, select a 16 mW, and stores the digital values of VWDC the register 28a corresponding thereto.
[0020]
The register 28a needs to be a nonvolatile memory. A flash memory or the like is suitable.
[0021]
For this purpose, the following processing is performed in the process inspection before shipment from the factory.
[0022]
First, for VRDC, as shown in FIG. 4, the PE0 control signal is always valid, the PW0 control signal is always invalid,
(I) Change the D / A output for determining VRDC so as to be X1 mW (6 mW), obtain the digital data Y1 at that time,
(Ii) Change the D / A output for determining VRDC so as to be X2 mW (8 mW), obtain the digital data Y2 at that time,
(Iii) X1, Y1, X2, and Y2 are stored in the register 28a.
[0023]
Next, for VWDC, as shown in FIG. 5, the PE0 control signal is always disabled, the PW0 control signal is always enabled,
(I) The D / A output for determining VWDC is changed so as to be X3 mW (12 mW), and the digital data Y3 at that time is acquired.
(Ii) Change the D / A output for determining VWDC so as to be X4 mW (16 mW), obtain the digital data Y4 at that time,
(Iii) Store X3, Y3, X4, and Y4 in the register 28a.
[0024]
When writing a signal, first, when a CD-RW disc to be recorded is set on the turntable, ATIP special information for determining CD-RW is read from the disc, and the disc-specific ε value (usually normal) 0.40 to 0.66) is obtained. Then, from the ε values taken read, the value stored in the register 28a, as follows, set the VRDC and VWDC, performs test writing, performs γ adjustment.
[0025]
Here, when the XEmW the PE0 (VRDC) required for γ adjustment voltage YW be set to a voltage YE and VWDC set to VRDC is determined as follows.
[0026]
( I) VRDC D / A conversion value corresponding to XEmW
YE = Y1 + ((Y2-Y1) / (X2-X1)) * (XE-X1)
Get in.
[0027]
( Ii) The laser output value XWmW of VWDC corresponding to XEmW is
XW = XE / ε
Get in.
[0028]
( Iii) D / A conversion value of VWDC corresponding to XWmW
YW = Y3 + ((Y4-Y3) / (X4-X3)) * (XW-X3)
Get in.
[0029]
Sets thus obtained YE in VRDC, by setting the YW to VWDC, can with setting the read disc-specific ε values began seen, setting the laser output to a target XEmW.
[0030]
As described above, according to the apparatus of the present embodiment, the ε value can be adjusted based on the data stored in the register 28a, and adjustment using a digital potentiometer or the like is not necessary. The tuning using digital potentiometer, which adjusts the laser output by the laser irradiation off focus, recovery time is borrowed or, there was a possibility that the negative effect on the disc occurs, these drawbacks by this embodiment Can be eliminated. Furthermore, since the output setting can be performed based on the digital data, the ε value can be adjusted with high accuracy.
[0031]
In the above example, the control signal is DC, but even if the PW0 control signal or the like is a pulse, if the duty ratio is known, the same calculation is possible.
[0032]
Also, as the value to be stored, by utilizing the two values which sandwich the laser output value for normal use, it can be performed with high accuracy setting. Note that the data stored by the three or more points, it is the upper up Rukoto further accuracy. Even in this case, linear interpolation may be performed. In some cases, interpolation using a quadratic curve or the like may be performed.
[0033]
【The invention's effect】
As described above, according to the first aspect of the present invention, the ε value set in accordance with the optical disk to be recorded can be adjusted based on the data stored in the storage means, such as a digital potentiometer. Adjustment by is unnecessary. In the adjustment using the digital potentiometer, the laser output is adjusted by irradiating the laser with the focus off, and it takes a long time to recover and the disk may be adversely affected. Can be resolved. Furthermore, since the output setting is performed based on the digital data, the ε value is adjusted with high accuracy.
[0034]
Also, as the value to be stored, by utilizing the two values which sandwich the laser output value for normal use, precise setting is performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a configuration of an optical disk recording apparatus according to the present invention.
FIG. 2 is a diagram showing a laser driving waveform.
FIG. 3 is a diagram showing a configuration for laser output.
FIG. 4 is a diagram for explaining digital data of a command value V RD C regarding laser output during erasing.
FIG. 5 is a diagram for explaining digital data of a command value V WD C for laser output at the time of writing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Optical disk 12 Spindle motor 14 Optical pick-up 16 Reading circuit 18 DRAM
20 writing circuit 22 rotation control circuit 24 CPU
26 Motor driver 28 Laser control unit 28a Register 30 VWDC generation circuit (VWDC generation unit)
32 VRDC generator circuit (VRDC generator)
34 Laser driver 36, 38 Switch 40 Laser diode 42 FMD (front monitor diode)

Claims (3)

An optical disk recording device for writing a signal to an optical disk,
The laser output for signal writing, the command value VRDC for the laser output at the time of erasing, and have twofold command value VWDC for the laser output at the time of writing, a storage unit for storing digital data corresponding thereto,
The command value VRDC for the laser output at the time of erasing and the digital data corresponding to the command value VWDC for the laser output at the time of writing stored in the storage means and the optical disc to be recorded are set. adjusting means for adjusting the command value VRDC for the laser output at the time of erasing and the command value VWDC for the laser output at the time of writing based on the ε value;
Have a,
At the stage before shipment, the digital data corresponding to the command value VRDC for the laser output at the time of erasing and the command value VWDC for the laser output at the time of the writing are the command value VRDC for the laser output at the time of erasing, Including data corresponding to two laser output values set across a representative laser output value corresponding to the command value VWDC for the laser output at the time of writing,
Based on the digital data including data corresponding to two laser output values set across the representative laser output value, and an ε value set according to the optical disc obtained from the optical disc and to be recorded An optical disk recording apparatus characterized in that a command value VRDC for the laser output at the time of erasing and a command value VWDC for the laser output at the time of writing are set and adjusted . The digital data corresponding to the VRDC is defined as Y1, Y2,
The digital data corresponding to the VWDC is defined as Y3, Y4,
The laser output PE0 during erasing is defined as X1 and X2,
The laser output PW0 at the time of writing is defined as X3 and X4,
PE0 required for γ adjustment is defined as XE,
The voltage to be set in the VRDC is defined as YE,
When the voltage to be set in the VWDC is determined as YW,
The D / A conversion value of the VRDC corresponding to the XE is
YE = Y1 + ((Y2-Y1) / (X2-X1)) * (XE-X1)
Is obtained at
The laser output value XW of the VWDC corresponding to the XE is
XW = XE / ε
Is obtained at
The D / A conversion value of the VWDC corresponding to the XW is
YW = Y3 + ((Y4-Y3) / (X4-X3)) * (XW-X3)
The optical disk recording apparatus according to claim 1, wherein the optical disk recording apparatus is acquired by: 3. The ε value set in accordance with the optical disk to be recorded is a ratio PE0 / PW0 between the laser output PE0 at the time of erasing and the laser output PW0 at the time of writing. Optical disk recording device.

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