JP2003157531A - Optical disk recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively adjust an ε value. SOLUTION: The data of an ε value is read from a CD-RW disk. A laser control unit 28 decides VRDC according to a necessary laser output based on a relation between the VRDC and the laser output stored in a register 28a. Then, the VRDC is divided by the εvalue read from the disk to decide proper VWDC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field 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 CDRW.

[0002]

2. Description of the Related Art Conventionally, as one of recording media,
CDs (Compact Discs) have become widespread, and signal rewritable CDRWs, CDRWs, have also become widely used. In this CDRW, trial writing is performed with a plurality of laser outputs that change stepwise in the trial writing area, and this is read out to determine the laser output at the time of writing. The ε value is adjusted accordingly. This ε value is a ratio (PE0 / PW0) of the power PE0 at the time of erasing and the power PW0 at the time of writing, and a value peculiar to the disk is set. Therefore, in the optical disc recording apparatus, first, C
The ε value is read from the DRW disc, and the laser output is set so as to have this ε value.

To this end, first, the laser output from the optical pickup is set to the erase power, and the focus is turned off to bring the CDRW disc on the turntable into a defocused state, and the front monitor is reflected by the reflected light. The output of the diode (FMD) is output as a DC voltage value by a low pass filter. Then, the value of the voltage value VRDC that determines the laser power at the time of erasing and the resistance value of the digital potentiometer having the power supply voltage Vcc (+5 V) at both ends are controlled so that the output value of this low-pass filter becomes a predetermined value. Then, the laser output at the time of writing (write power: corresponding to VWDC) is adjusted, and the ε value is adjusted accordingly.

[0004]

In the conventional adjustment of the ε value as described above, the focus is turned off during the adjustment, so that there is a problem that it takes time to adjust the focus after that. Further, although the focus is off, the disc is irradiated with the laser, which may adversely affect the disc. Further, there is a problem that the adjustment is performed by the output of the low-pass filter, the detection accuracy of the laser output is low, and the adjustment accuracy is low.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical disk recording apparatus capable of effectively adjusting the ε value.

[0006]

DISCLOSURE OF THE INVENTION The present invention is an optical disk recording apparatus for writing a signal on an optical disk, which is a VRDC which is an output value of a signal writing laser and which is a command value for a laser output at the time of erasing. Regarding VWDC which is a command value for the laser output at the time of writing,
Storage means for storing digital data corresponding to these, and VRDC and VW stored in this storage means
Based on the digital data corresponding to DC and the ε value set according to the optical disc to be recorded, the command value VR
Adjusting means for adjusting DC and VWDC.

As described above, according to the present invention, the ε value can be adjusted based on the data stored in the storage means, and the adjustment by the digital potentiometer or the like is unnecessary. In the adjustment using the digital potentiometer, the laser output is adjusted by irradiating the laser with the focus off, and it may take a long time to recover or the disk may be adversely affected. Can be resolved. Furthermore, since the output can be set based on the digital data, the ε value can be adjusted with high accuracy.

Further, it is preferable that the digital data corresponding to the VRDC and the VWDC include data corresponding to two laser output values set by sandwiching a typical laser output value corresponding to the VRDC and the VWDC, respectively. is there.

As described above, by using the two values sandwiching the laser output value that is normally used as the stored values, highly accurate setting can be performed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the apparatus of the embodiment. The optical disk 10 is a spindle motor 1
2 rotates at a predetermined rotation speed. Then, the optical pickup 14 irradiates the optical disc 10 with laser light and receives the reflected light. The optical pickup 14 supplies the reception circuit 16 with a reception signal corresponding to the received light. The read circuit 16 restores read data from the received signal and writes it in the DRAM 18. Then, the read data in the DRAM 18 is appropriately output. For example, it is supplied to the computer via an interface and a communication bus.
The optical pickup 14 has a front monitor diode (FMD) that detects the intensity of reflected light.

Further, the DRAM 18 stores write data supplied from a computer or the like via a communication bus or an interface. The write data in the DRAM 18 is read by the write circuit 20 and converted into a predetermined write signal by the laser control unit 28 and supplied to the optical pickup 14. Optical pickup 14
Emits light according to the write signal, and writing is performed on the optical disc 10.

The read signal from the optical pickup 14 obtained by 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.
The rotation control circuit 22 is supplied with a signal from the CPU 24 regarding the target rotation speed, and the rotation control circuit 22 compares the detected rotation speed of the optical disc 10 with the target rotation speed.
The motor rotation control signal is supplied to the motor driver 26.
Then, the motor driver 26 controls the spindle motor 12 according to the motor rotation control signal, whereby the rotation speed of the optical disk 10 is controlled to the target rotation speed.

Further, a signal regarding the intensity of light received by the optical pickup 14 is supplied to the laser controller 28, which controls the laser output of the optical pickup 14.

Here, when writing a signal to the optical disk 10, a predetermined signal is written in the trial writing area prior to recording the signal, 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 before trial writing. The ε value is the ratio (PE0 / PW0) of the laser output PE0 at the time of erasing and the laser output PW0 at the time of writing the signal in the CD-RW, and is set as follows.

Here, the setting of the ε value will be described. First, the laser output is VRDC, which is a voltage signal supplied to the laser oscillator of the optical pickup 14, and VWDC.
Controlled by. That is, as shown in FIG. 2, in the output from the laser control unit 28, VRDC is output by the PE0 control signal during signal erasing (erasing), and PW0 control signal during signal writing (writing). A voltage that fluctuates between VWDC and GND is output depending on the state. Then, according to this voltage, the laser is output, and the signal is erased and written to the CD-RW disc.

FIG. 3 shows a configuration for laser output in the laser control unit 28. VWDC generator 3
The 0 and VRDC generator 32 generates VWDC and VRDC, respectively, in response to a command from the CPU 24. In addition, the write circuit 20 outputs the PW according to the write data.
0 control signal and PE0 control signal are generated. This PW
The 0 control signal and the PE0 control signal are transmitted from the VWDC generation circuit 30 and the VRDC generation circuit 32 to the laser driver 3
The on / off of the switches 36 and 38 provided on the path up to 4 is controlled. Therefore, the signal supplied to the laser driver 34 is controlled according to the write data. And
The laser driver 34 controls the light emission by the laser diode 40 based on VWDC and VRDC supplied. The output of the laser diode 40 is detected by the front monitor diode (FMD) 42 and
It is supplied to the DC generation circuit 30 and the VRDC generation circuit 32,
These VWDC generation circuit 30 and VRDC generation circuit 32
Outputs the voltage values of VWDC and VRDC to be output to the FMD42.
Control according to the detected value of.

The VWDC generation circuit 30, the VRDC generation circuit 32, the switches 36 and 38 are provided in the laser control unit 28.
The laser driver 34, the laser diode 40, and the FMD 42 are provided inside the optical pickup 14.

In this embodiment, the data of VRDC and VWDC corresponding to the predetermined laser output are stored in the register 28a. That is, this register 28a has V
Data about RDC and VWDC is written in the register 28a. For example, digital data obtained by converting VRDC and VWDC corresponding to two typical laser output values by the A / D converter is stored in the register 28a. Laser output for VRDC is usually 7 m
It is about W, and 6 mW and 8 mW are selected as typical two points, and the corresponding digital value of VRDC is stored in the register 28a. Moreover, the laser output corresponding to VWDC is usually about 14 mW, and the typical two points are 1
2 mW and 16 mW are selected, and the corresponding digital value of VWDC is stored in the register 28a.

The register 28a needs to be a non-volatile memory. A flash memory or the like is suitable.

For this reason, the following processing is performed in the process inspection before shipment from the factory.

First, for VRDC, as shown in FIG. 4, the PE0 control signal is always valid and the PW0 control signal is always invalid so that (i) X1 mW (6 mW) is obtained.
The D / A output that determines VRDC is changed, the digital data Y1 at that time is acquired, and (ii) X2mW (8m
W /), the D / A output that determines VRDC is changed, digital data Y2 at that time is acquired, and (ii)
i) Store X1, Y1, X2 and Y2 in the register 28a.

Next, for VWDC, as shown in FIG. 5, the PE0 control signal is always invalid, the PW0 control signal is always valid, and (i) VWDC is determined so that it becomes X3 mW (12 mW). A output is changed, digital data Y3 at that time is acquired, and (ii) X4mW (1
6mW), the D / A output that determines VWDC is changed, and the digital data Y4 at that time is acquired,
(Iii) Store X3, Y3, X4, Y4 in the register 28a.

When writing a signal, when the CD-RW disc to be recorded is first set on the turntable, the ATIP special information for discriminating the CD-RW is read from the disc, and the disc-specific ε is read from this information. A value (usually 0.40 to 0.66) is obtained. Then, from the read ε value and the value stored in the register 28a, VRDC and VWDC are set in the following manner, trial writing is performed, and γ adjustment is performed.

Here, PE0 (VRD required for γ adjustment)
When C) is XEmW, the voltage YE set to VRDC and the voltage YW set to VWDC are determined as follows.

(I) D / of VRDC corresponding to XEmW
A conversion value is YE = Y1 + ((Y2-Y1) / (X2-X1)) *
(XE-X1).

(Ii) The VWDC laser output value XWmW corresponding to XEmW is obtained by XW = XE / ε.

(Iii) The D / A conversion value of VWDC corresponding to XWmW is YW = Y3 + ((Y4-Y3) / (X4-X3)) *
(XW-X3).

By setting YE thus obtained in VRDC and YW in VWDC, an ε value unique to the read ε value is set and a laser output is set to a target XEmW. You can

As described above, according to the apparatus of this embodiment,
Based on the data stored in the register 28a, ε
The value can also be adjusted, eliminating the need for adjustment using a digital potentiometer or the like. In the adjustment using the digital potentiometer, the laser output is adjusted by irradiating the laser with the focus off, and it may take a long time to recover or the disk may be adversely affected. Can be resolved. Furthermore, since the output can be set based on the digital data, the ε value can be adjusted with high accuracy.

In the above example, the control signal is DC, but the PW0 control signal or the like can be used as a pulse as long as the duty ratio is known.

Further, by using two values sandwiching the laser output value which is normally used as a stored value,
Highly accurate setting is possible. The accuracy can be further increased by storing three or more points of data to be stored. Also in this case, linear interpolation may be performed. Depending on the case, interpolation using a quadratic curve or the like may be performed.

[0033]

As described above, according to the present invention,
The ε value can also be adjusted based on the data stored in the storage means, and the adjustment by a digital potentiometer or the like becomes unnecessary. In the adjustment using the digital potentiometer, the laser output is adjusted by irradiating the laser with the focus off, and it may take a long time to recover or the disk may be adversely affected. Can be resolved. Furthermore, since the output can be set based on the digital data, the ε value can be adjusted with high accuracy.

Further, by using two values sandwiching the laser output value which is normally used as a stored value,
Highly accurate setting is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus according to an embodiment.

FIG. 2 is a diagram showing a laser drive waveform.

FIG. 3 is a diagram showing a configuration for laser output.

FIG. 4 is a diagram illustrating digital data of VRDC.

FIG. 5 is a diagram illustrating VWDC digital data.

[Explanation of symbols]

10 optical disk, 12 spindle motor, 14 optical pickup, 16 readout circuit, 18 DRAM, 2
0 writing circuit, 22 rotation control circuit, 24 CP
U, 26 Motor driver, 28 Laser controller, 28
a register.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshihiko Hiroshima             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F-term (reference) 5D090 AA01 CC01 CC02 DD03 EE02                       KK03

Claims (2)

[Claims] 1. An optical disk recording apparatus for writing a signal on an optical disk, comprising: VRDC which is an output of a signal writing laser and which is a command value for a laser output during erase, and a command for a laser output during writing. VWDC which is a value, storage means for storing digital data corresponding to these values, and VRDC and VWDC stored in this storage means
Command value VRDC based on the digital data corresponding to and the ε value set according to the optical disc to be recorded.
And an adjusting means for adjusting VWDC, and an optical disk recording apparatus comprising: 2. The apparatus according to claim 1, wherein the digital data corresponding to the VRDC and the VWDC are two laser output values set with a typical laser output value corresponding to the VRDC and the VWDC respectively. An optical disc recording device containing corresponding data.