JP2003281770A - Optical disk information recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk recording/reproducing device of which the number of components and cost are reduced by monitoring the power of semiconductor lasers for a CD-R/RW and for a DVD recording standard with one photodetector. <P>SOLUTION: The optical disk recording/reproducing device has: the photodetector 25 which is shared between the CD-R/RW and the DVD+R/RW to monitor the light emitting power of a semiconductor; a switch 26 which can arbitrarily select the output destination of the output signal of the photodetector 25 based on a switch control signal 29 from a system controller (not illustrated); an amplifier 27 for amplifying the output of the switch 26 and shifting the level of a monitor signal to match resolution for CD-R/RW; and an amplifier 28 for shifting the level of the monitor signal to match resolution for DVD+R/ RW. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk information recording device, and more particularly to a circuit for monitoring the recording power of a semiconductor laser.

[0002]

2. Description of the Related Art Semiconductor lasers are widely used as light sources in various fields because they are small in size and can perform high-speed modulation with a small drive current. However, the relationship between the drive current of the semiconductor laser and the light output changes remarkably depending on the temperature. Therefore, when the light intensity is set to a desired value, its stability becomes a problem. In order to solve this problem, especially in the optical disk device, the APC
Using the (Automatic Power Control) circuit, the light output of the semiconductor laser is monitored by the light receiving element, and a signal proportional to the light output of the semiconductor laser generated from this light receiving element,
The forward current of the semiconductor laser is constantly controlled so that the emission level command signal becomes equal. This technique is also used in a CD-R / RW drive, which is a recordable / reproducible optical disk device, and controls the power of the laser.

FIG. 7 shows a conventional CD-R / RW, DVD + R.
An example of a power monitor circuit inside a pickup of a drive compatible with both / RW standard is shown. The configuration of this pickup 77 is such that the power monitor circuit 76 is
A light receiving element 70 used for the power monitor of the semiconductor laser at the time of R / RW, an amplifier 71 for amplifying the output signal of the light receiving element 70, and a light receiving element 73 used for the power monitor of the semiconductor laser when the optical disk is DVD + R / RW. , Light receiving element 7
It is composed of an amplifier 74 which amplifies the output signal of No. 3. From this figure, the power monitor signals 72, 75 output from the power monitor circuit 76 are proportional to the optical output of the semiconductor laser, and the power monitor circuit 76 indicates the optical output value of the laser power as a voltage value CD-R / RW, DVD + R / R
It is output to the system controller in the drive compatible with both W standards. The resolutions of the power monitor signals 72 and 75 are the maximum optical output value of the semiconductor laser and the power monitor circuit 7.
6 depends on the operating voltage. The resolution is the voltage level of the power monitor signal with respect to the optical output of 1 mW of the semiconductor laser, and the higher the resolution, the better. Also, C
Since the recording speed of D-R / RW is faster than that of DVD + R / RW, the recording power at the highest speed is DVD + R / RW.
Bigger than that. From this, CD-R / RW and D
It can be seen that the resolutions of the power monitor signals of VD + R / RW are different. Therefore, in FIG. 7, the amplifier 71 and the amplifier 7
Reference numeral 4 level-converts the monitor signals so that the output signals from the light receiving elements 70 and 73 match the resolution of the respective optical disks. These monitor signals 72 and 75 are output to the system controller, and power control of the optical output of the semiconductor laser is realized. Thus, the conventional CD-R / RW,
The DVD + R / RW standard compatible drive has a light receiving element 7
Two light receiving elements are used to monitor the optical output of the semiconductor laser as in Nos. 0 and 73.

In addition, the CD-R / RW drive is being standardized on a personal computer at present, and C is also available on Windows (registered trademark) of Microsoft Corporation, which is the most common OS.
CD-R can be recorded on the D-R / RW media.
/ RW drives have become commonplace for users. Furthermore, in terms of performance, CD-R /
The speed of recording and reproducing on RW media is increasing. Further, as the recording speed of the CD-R / RW medium is increased, it is necessary to increase the optical output of the semiconductor laser, which increases the output of the semiconductor laser of the present CD-R / RW drive. Recently, these CD-R /
A new recording medium standard D in the RW drive
A drive capable of recording on a large-capacity recording medium such as a VD-ROM has come out. DVD-ROM type recording media standards are DVDRAM, DVD + R / RW, DV
Standards such as D-R / RW are issued by various companies, and CD-
It is possible to perform recording with a larger capacity than the standard of CD-ROM type recording media such as R / RW. (CD-R / RW: 65
0MB, DVDRAM, DVD + R / RW, DVD-R
/ RW: 4.7 GB) DVDRAM, DVD + R / R
Since W and DVD-R / RW (hereinafter referred to as the DVD recording standard) have just been developed recently, the semiconductor laser is much slower than the CD-R / RW whose recording speed is increasing. The recording power of is also low. Such a CD-R / RW + DVD recording standard drive currently commercialized has a semiconductor laser for CD-R / RW and a semiconductor laser for DVD recording standard, respectively. This is CD-
This is because the wavelength of the semiconductor laser is different between R / RW and DVD recording standards. In addition, the light receiving elements for monitoring the optical output of each of these semiconductor lasers are also respectively CD-R / R.
There are two types, one for W and one for DVD recording standard, and the circuits for processing the output signals of these light receiving elements are also different. This is C
This is due to the difference in the recording power between the D-R / RW and the DVD recording standard, because the resolution of the semiconductor laser power monitor circuit determined by the operating voltage of the light receiving element in the drive and the optical output of the semiconductor laser is different.

[0005]

As shown in FIG. 7, C
The D-R / RW + DVD recording standard drive requires two types of light receiving elements to monitor its optical output, and thus has a problem that the number of parts is large and the cost is high. In view of such problems, the present invention is a conventional CD
-Optical disc that realizes reduction of the number of parts and cost by performing the power monitoring of the semiconductor laser by using a dedicated light receiving element for R / RW and DVD recording standard, by using one light receiving element. An object is to provide a recording / reproducing device.

[0006]

In order to solve the above problems, the present invention provides an optical disk information recording capable of writing information on at least two optical disks having different laser wavelengths. In the device, one light receiving element for monitoring the emission power of at least two or more laser light sources having different laser wavelengths, and signal switching means for switching the path of the output signal of the light receiving element,
At least two or more amplifiers for amplifying the output signal of the light receiving element from the signal switching means by different amplification factors, and the signal switching means is based on a laser wavelength monitored by the light receiving element. The output signal of the light receiving element is connected to any one of the at least two amplifiers. The light receiving element has wavelength characteristics and sensitivity characteristics, each of which has slightly different characteristics. Therefore, when it is incorporated into a circuit and used for laser power monitoring, it is corrected by a peripheral amplifier so that the total characteristics match. In other words, when laser light of different wavelengths is received by one light receiving element, the output level thereof is slightly different depending on the wavelength even with the same power. If this level difference is confirmed in advance, the correct level can be monitored by correcting it by the amplifier. According to this invention, one light receiving element for monitoring the emission power of at least two or more laser light sources having different laser wavelengths, a switch for switching the path of the output signal of this light receiving element, and an output signal from this switch are By switching to at least two amplifiers having different amplification factors, the light receiving element can be shared and the cost can be reduced. It is also an effective means of the present invention that the at least two or more amplifiers are configured to amplify the emission powers of the at least two or more laser light sources to optimum signal levels, respectively. . As described above, the light receiving element has wavelength characteristics and sensitivity characteristics, and each has slightly different characteristics. Therefore, when it is incorporated into a circuit and used for laser power monitoring, it is corrected by a peripheral amplifier so that the total characteristics match. Therefore, at least two or more amplifiers are appropriately corrected based on the signals from at least two or more light receiving elements so that the power of the laser light received by the light receiving elements has a linear characteristic. According to such a technical means, at least two or more amplifiers are configured to amplify the emission powers of at least two or more laser light sources having different wavelengths to the optimum signal levels, respectively, so that one light reception is performed. At least two or more laser light sources can be individually and accurately power-controlled from the signal from the element.

According to a third aspect of the present invention, in an optical disc information recording apparatus capable of writing information on at least two optical discs having different laser wavelengths, at least two laser light sources having different laser wavelengths are provided. One light receiving element for monitoring the light emission power, a first amplifier for amplifying the output signal of the light receiving element, a signal switching means for switching the output path of the first amplifier, and the first signal from the signal switching means. A second amplifier which further amplifies the output signal of the amplifier, and the signal switching means outputs the output signal of the first amplifier as it is, based on the laser wavelength monitored by the light receiving element, It is characterized in that it is possible to select whether to output through the second amplifier. When the amplifiers are connected in a cascade, the amplification factor of the second stage amplifier can be small. In general, amplifiers
If the amplification factor is increased, the operation becomes unstable and the linearity deteriorates. Therefore, the output of the first amplifier is
It is possible to reduce the amplification factor of the second amplifier by amplifying with the second amplifier. According to this invention,
Based on the laser wavelength monitored by the common light receiving element, the switch can select whether to output the output signal of the first amplifier as it is or to output it through the second amplifier. It can be obtained with a simple configuration. According to claim 4, the first amplifier is configured to amplify the emission power of one of the at least two or more laser light sources to an optimum signal level, and the second amplifier is the first amplifier. Further amplify the output level of
It is also an effective means of the present invention that the other light emitting power of the at least two laser light sources is configured to be amplified to an optimum signal level. When the amplifiers are connected in cascade, the second-stage amplifier may have an amplification factor that is insufficient with respect to the first-stage amplification factor. Therefore, the amplification factor of the second stage can be small, and the amplifier design itself becomes easy. For example, when the first amplifier requires the amplification factor of 2 and the second amplifier requires the amplification factor of 4, originally, two kinds of amplifiers having the amplification factors of 2 and 4 are required.
In the case of the present invention, the amplification factor of the second amplifier may be 2. According to such technical means, the first amplifier is configured to amplify the emission power of one of the at least two laser light sources to the optimum signal level, and the second amplifier.
Is configured to further amplify the output level of the first amplifier to amplify the light emission power to the optimum signal level, the configuration of the second amplifier is simplified,
Linearity is improved.

According to a fifth aspect of the present invention, in an optical disc information recording apparatus capable of writing information on at least two optical discs having different laser wavelengths, at least two laser light sources having different laser wavelengths are provided. The light receiving element is provided with one light receiving element for monitoring the light emission power, signal switching means for switching the output path of the output signal of the light receiving element, and an amplifier for amplifying the output signal from the signal switching means. It is characterized in that the signal switching means can select whether to output the output signal of the light receiving element as it is or to output it through the amplifier based on the laser wavelength. When monitoring laser light of at least two or more wavelengths, it is possible to directly input the higher signal level to the control circuit without passing through the amplifier. Then, if the signal is corrected to a signal level suitable for the resolution on the control circuit side, the number of amplifiers can be reduced. According to this invention, it is possible to select whether to output the output signal of the light receiving element as it is or to output it through the amplifier based on the laser wavelength monitored by the light receiving element. Therefore, the number of amplifiers can be reduced. , Can reduce the cost. Claim 6
It is also an effective means of the present invention that the signal switching means is switching-controlled by a signal from an external control device. When monitoring multiple different wavelengths of laser light with one light receiving element, which side is the wavelength currently being monitored?
The controller recognizes it. Therefore, the signal switching means is most surely controlled by this control device. According to such a technical means, the signal switching means is switched and controlled by the signal from the external control device, so that the signal can be reliably switched. A seventh aspect of the present invention comprises one light receiving element for monitoring the emission power of at least two or more laser light sources having different laser wavelengths, and the output signal of the light receiving element matches the resolution of the optical disc designated by the control device. Correcting to a different signal level is also an effective means of the present invention. As stated in claim 6, the wavelength being monitored is known by the controller. Therefore, if the control device has sufficient processing capacity, it is possible to directly detect the output signal of the light receiving element and correct it to a signal level suitable for the resolution for each wavelength used. According to such technical means, one light receiving element for monitoring the emission power of at least two or more laser light sources having different laser wavelengths is provided, and the output signal of this light receiving element has the resolution of the optical disc designated by the control device. Since the signal levels are adjusted to match each other, an amplifier is not required and the cost can be realized at the minimum cost.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, the constituent elements, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely explanatory examples, not the gist of limiting the scope of the present invention thereto, unless specifically stated. . FIG. 1 is a block diagram showing the configuration of an optical disc device according to an embodiment of the present invention. This configuration is a CD-R / RW
It is realized by a composite machine (combo drive) of a drive and a DVD-ROM drive. A CD or DVD optical disc 1 which is rotated by a spindle motor 2;
LV (Constant Linear Velocity) or C
AV (Constant Angular Velocity) controlled spindle motor 2 and optical pickup 3 not shown
A motor driver 5 for driving an actuator in the motor driver, a servo circuit 9 for generating a signal for servo control in the motor driver 5, and an RF amplifier for processing each signal from a light receiving element (not shown) in the optical pickup 3. 6
An optical pickup 3 including a semiconductor laser light source for DVD, a semiconductor laser light source for DVD, an optical system such as an objective lens, and an actuator, an LD driver 4 for controlling the light amount of the laser light source, and the like; An ATIP decoder 7 for extracting the ATIP (Absolute Time In Pregroove) information engraved on the CD, a CD encoder circuit 8 for generating an accurate data writing position, and an EFM (Eight to Fourteen Modulatio) for the binarized RF signal.
n) CD / DVD decoder 10 for modulation, buffer RAM 11 for temporarily storing data, and this buffer RAM
A buffer manager 14 for controlling 11; a host interface 12 connected to the buffer RAM 11 and having an ATAPI or SCSI interface;
EFM after the D / A converter 13 which is connected to the / DVD decoder 10 and outputs an audio signal and the error correction code is disabled or interleaved
A system controller having a CD-ROM encoder 15 for modulating, a CD-ROM decoder 16 for performing deinterleaving (rearrangement) and error correction processing of EFM-demodulated data, and a storage device 18, and being in charge of overall control. It is composed of 17.

Next, referring to FIG. 1, a CD system (CD-ROM /
The operation of R / RW) will be described. In addition, DVD system (DV
The operations of the D-ROM and the DVD + R / RW) are the same, so the description thereof will be omitted. The optical disc 1 (CD or CD-ROM disc) is rotationally driven by the spindle motor 2. The spindle motor 2 is controlled by the motor driver 5 and the servo circuit 9 so as to have a constant speed. Further, the optical pickup 3 has a semiconductor laser (Laser Diode) for a CD system and a DVD system, which are not shown, respectively, and has an optical system (lens, etc.), a focus actuator (a lens so that the laser beam is focused on the disc). The mechanism that moves the position of the disk in the direction perpendicular to the disk), the track actuator (the mechanism that moves the lens in the disk radial direction (sledge direction) so that the focus of the laser beam traces the track), and the light receiving element, position sensor, etc. A power monitor circuit, which is the subject of the present invention, is built in, and the optical disk 1 is irradiated with laser light. Also, the optical pickup 3
The whole can be moved in the sledge direction by a seek motor (not shown). These focus actuator, track actuator, and seek motor are laser driven by a motor driver 5 and a servo circuit 9 based on servo signals such as focus error signal (FE) and track error (TE) signals obtained from a light receiving element and a position sensor. The spot is controlled so that it is located at the destination. In the case of data reading, the reproduction signal obtained by the optical pickup 3 is amplified by the RF amplifier 6 and binarized (digitized), and then input to the CD / DVD decoder and EFM demodulated. The EFM demodulated data is subjected to deinterleaving (reordering) and error correction. After that, this data is temporarily stored in the buffer RAM 11 by the buffer manager 14 and sent to the host computer at once through the host I / F 12 when the sector data is prepared. C for music data
The data output from the D decoder 10 is input to the D / A converter 13 and an analog audio signal is output.

Next, when writing data, the host I / F
The data sent from the host through 12 is temporarily stored in the buffer RAM 11 by the buffer manager 14, and writing is started when the data is stored in the buffer to some extent. Before that, the structure of the recording power prepared in the inner circumference of the disk is set. The optimum recording power is determined in the area. Also, the laser spot must be located at the writing start point. This point is a wobble (Wo
bble) signal. ATI for wobble signal
The absolute time information called P is included, and this information is retrieved by the ATIP decoder 7. Further, the sync signal generated by the ATIP decoder 7 is input to the CD encoder 8 to enable writing of data at an accurate position. The data in the buffer RAM 11 is CD-RO.
After adding the error correction code and interleaving (sorting) by the M encoder 15 and the CD encoder 8,
It is EFM-modulated and recorded on the optical disc 1 via the LD driver 4 and the optical pickup 3. The recording is performed by the optical pickup 3 by alternately switching the laser beam between the recording beam and the reproducing beam. Figure 2 shows CD-R / RW and DV
It is a figure which shows the relationship between the level of the power monitor signal of D + R / RW, and the power of a semiconductor laser. In the figure CD-R / R
This is an example in the case where the maximum recording speed of W and DVD + R / RW are 32x speed and 2.4x speed, respectively, and the recording power at the maximum recording speed is 60mW and 20mW and the operating voltage of the power monitor circuit is 5v. . From this figure, CD-
The characteristic of R / RW is as shown by the straight line 21, and the point b at which the operating voltage of the power monitor circuit becomes 5 v shows 60 mW, and D
The characteristic of VD + R / RW is as shown by a straight line 20, and the point a at which the operating voltage of the power monitor circuit becomes 5v indicates 20 mW. For example, the power monitor signal at 1 mW is CD-R.
In case of / RW, it becomes B, and in case of DVD + R / RW, it becomes A
It can be seen that the resolution is different.

FIG. 3 is a circuit diagram of the power monitor circuit according to the first embodiment of the present invention. As shown in the figure, the power monitor circuit 30 has a CD-R / RW and a DVD +.
A light receiving element 25 for monitoring a semiconductor light output commonly used for R / RW, and a switch 26 capable of arbitrarily selecting an output destination of an output signal of the light receiving element 25 by a switch control signal 29 from a system controller (not shown). , The output of the switch 26 is amplified, and the CD-R
An amplifier 27 for level-shifting the monitor signal to the resolution for / RW and an amplifier 28 for level-shifting the monitor signal to the resolution for DVD + R / RW. Output signals (monitor signals) 32 and 33 from these amplifiers 27 and 28 are output to the system controller in the drive. The system controller switches the switch 26 to the A side when the user is using the CD-R / RW. The A side is a path for generating a monitor signal for CD-R / RW, and here, the light receiving element 2
The output signal 5 is input to the amplifier 27, amplified, and then output from the power monitor circuit 30. The system controller uses the monitor signal 32, which is the output signal, for C
The power of the semiconductor laser is controlled when the D-R / RW is used. On the other hand, when the user is using the DVD + R / RW, the system controller switches the switch to the B side. The B side is a path for generating a monitor signal for DVD + R / RW. Here, the output signal of the light receiving element 25 is input to the amplifier 28 and amplified, and then the power monitor circuit 30
Is output from. As with the CD-R / RW, the system controller uses this output signal, monitor signal 3
3 is used to control the power of the semiconductor laser when DVD + R / RW is used. With the above configuration and operation, the power control of the semiconductor laser is realized by the power monitor circuit 30 of one light receiving element 25.

FIG. 4 is a circuit diagram of a power monitor circuit according to the second embodiment of the present invention. As shown in the figure, the configuration of this power monitor circuit is as follows: CD-R / RW and DVD + R /
A light receiving element 35 for monitoring the semiconductor light output commonly used for RW, and an output of the light receiving element 35 are amplified to
An amplifier 36 for level-shifting the monitor signal to the resolution for D / R / RW, a switch 37 for arbitrarily selecting the output destination of the output signal of the amplifier 36 by a switch control signal 41 from a system controller (not shown), It is composed of an amplifier 38 for level-shifting the output signal of the amplifier 36 to a resolution for DVD + R / RW. The system controller is the user's CD-
When R / RW is used, the switch 37 is switched to the A side. The A side is a path for the monitor signal for CD-R / RW, and the output signal from the light receiving element 35, which is amplified by the amplifier 36 to a signal level matching the resolution for CD-R / RW, is on this path. Then, the signal is not particularly processed and is output from the power monitor circuit 39. The system controller uses the monitor signal 42, which is the output signal, to control the power of the semiconductor laser when the CD-R / RW is used. On the other hand, when the user is using the DVD + R / RW, the system controller switches the switch to the B side. The B side is a path for generating a monitor signal for DVD + R / RW. Here, the output signal of the amplifier 36 is amplified by the amplifier 38 to a signal level matching the resolution for DVD + R / RW, and then from the power monitor circuit 39. Is output. As in the case of using the CD-R / RW, the system controller uses the monitor signal 43 which is the output signal to control the power of the semiconductor laser when using the DVD + R / RW. With the above configuration and operation, the power control of the semiconductor laser is realized by the power monitor circuit 39 of one light receiving element 35.

FIG. 5 is a circuit diagram of a power monitor circuit according to the third embodiment of the present invention. As shown in the figure, the configuration of the power monitor circuit 55 includes a CD-R / RW and a DVD-
A light receiving element 50 for monitoring a semiconductor light output commonly used for R / RW, and a switch 51 capable of arbitrarily selecting an output destination of an output signal of the light receiving element 50 by a switch control signal 57 from a system controller,
It is composed of an amplifier 52 for level shifting the output signal of the switch 51 to the resolution for DVD + R / RW.
The system controller switches the switch 51 to the A side when the user is using the CD-R / RW.
The A side is a path for a monitor signal for CD-R / RW, and the output signal from the light receiving element 50 is output from the power monitor circuit 55 without performing any signal processing on this path. The system controller uses the monitor signal 53, which is the output signal, to control the power of the semiconductor laser when the CD-R / RW is used. Meanwhile, the user is DVD + R
When using / RW, the system controller switches the switch to the B side. B side is DVD + R / R
This is a path for generating a monitor signal for W. Here, the output signal of the switch is amplified by the amplifier 52 to a signal level that matches the resolution for DVD + R / RW, and then output from the power monitor circuit 55. As in the case of using the CD-R / RW, the system controller uses the output monitor signal 54 to control the power of the semiconductor laser when using the DVD + R / RW. With the above configuration and operation,
Power control of the semiconductor laser is realized by the power monitor circuit of one light receiving element. FIG. 6 is a circuit diagram of a power monitor circuit according to the fourth embodiment of the present invention. The configuration of the power monitor circuit 62 is as follows: CD-R / RW and DVD-R / RW
It is composed only of the light receiving element 60 for monitoring the semiconductor light output commonly used for RW. The wavelength being monitored is known by the system controller. Therefore, if the system controller has enough processing capacity,
It is possible to directly detect the output signal 61 of the light receiving element 60 and correct it to a signal level suitable for the resolution for each wavelength used. This does not require an amplifier and can be realized at a minimum cost.

[0015]

As described above, according to the invention of claim 1, one light receiving element for monitoring the emission power of at least two or more laser light sources having different laser wavelengths,
By switching either the switch for switching the path of the output signal of the light receiving element or the output signal from this switch to at least two or more amplifiers having different amplification factors, the light receiving element can be shared and the cost can be reduced. It will be possible. Further, in the present invention, at least two or more amplifiers are configured to amplify the light emission powers of at least two or more laser light sources having different wavelengths to the optimum signal levels, so that one light receiving element is provided. The signals from the at least two or more laser light sources can be individually and accurately power-controlled. Further, in claim 3, the switch outputs the output signal of the first amplifier as it is, based on the laser wavelength monitored by the common light receiving element,
Since it is possible to select whether to output via the second amplifier, an appropriate monitor signal can be obtained with a simple configuration. Further, in claim 4, the first amplifier is configured to amplify the emission power of one of the at least two laser light sources to an optimum signal level, and the second amplifier is the same as the first amplifier. Since the output level is further amplified and the emission power is amplified to the optimum signal level, the configuration of the second amplifier is simplified and the linearity is improved. Further, according to the present invention, it is possible to reduce the number of amplifiers because it is possible to select whether the output signal of the light receiving element is directly output by the switch or output through the amplifier based on the laser wavelength monitored by the light receiving element. ,
The cost can be reduced. In the sixth aspect, since the signal switching means is controlled to be switched by the signal from the external control device, it is possible to reliably switch the signal.
According to a seventh aspect of the present invention, one light receiving element for monitoring the emission power of at least two laser light sources having different laser wavelengths is provided, and the output signal of this light receiving element matches the resolution of the optical disc designated by the control device. Since it is corrected to each signal level, you do not need an amplifier,
It can be realized at the minimum cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical disc device according to an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the levels of power monitor signals of a CD-R / RW and a DVD + R / RW of the present invention and the power of a semiconductor laser.

FIG. 3 is a circuit diagram of a power monitor circuit according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram of a power monitor circuit according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram of a power monitor circuit according to a third embodiment of the present invention.

FIG. 6 is a circuit diagram of a power monitor circuit according to a fourth embodiment of the present invention.

FIG. 7 is a circuit diagram of a power monitor circuit in a pickup of a conventional CD-R / RW and DVD + R / RW standard compatible drive.

[Explanation of symbols]

25 light receiving element, 26 switch, 27, 28 amplifier, 30 power monitor circuit, 31 pickup

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5D090 AA01 BB03 BB05 CC01 DD03                       EE01 FF08 KK03 LL08                 5D119 AA05 AA23 AA41 BA01 BB02                       BB04 DA01 EC45 EC47 FA05                       FA08 HA12 HA21 HA45 HA68                 5D789 AA05 AA23 AA41 BA01 BB02                       BB04 DA01 EC45 EC47 FA05                       FA08 HA12 HA21 HA45 HA68

Claims (7)

[Claims] 1. An optical disc information recording apparatus capable of writing information on at least two optical discs having different laser wavelengths used, wherein the emission power of at least two laser light sources having different laser wavelengths is monitored. One light receiving element, a signal switching means for switching the path of the output signal of the light receiving element, and at least two or more amplifiers for amplifying the output signal of the light receiving element from the signal switching means with different amplification factors, The optical disc information recording apparatus, further comprising: a signal switching means for connecting the output signal of the light receiving element to any one of the at least two amplifiers based on a laser wavelength monitored by the light receiving element. . 2. The at least two amplifiers are configured to amplify the emission powers of the at least two laser light sources to optimum signal levels, respectively. Optical disk information recording device. 3. An optical disc information recording apparatus capable of writing information on at least two optical discs having different laser wavelengths, wherein emission powers of at least two laser light sources having different laser wavelengths are set. One light receiving element to be monitored, a first amplifier for amplifying an output signal of the light receiving element, a signal switching means for switching an output path of the first amplifier, and a first amplifier from the signal switching means. A second amplifier for further amplifying the output signal, wherein the signal switching means outputs the output signal of the first amplifier as it is, or the second amplifier based on the laser wavelength monitored by the light receiving element. An optical disk information recording device, wherein output can be selected via an amplifier. 4. The first amplifier comprises the at least two.
The second amplifier is configured to amplify the emission power of one of the one or more laser light sources to an optimum signal level,
The output level of said 1st amplifier is further amplified, and it is comprised so that the light emission power of the other of said at least 2 or more laser light sources may be amplified to an optimal signal level. The optical disk information recording device described. 5. In an optical disc information recording apparatus capable of writing information on at least two optical discs having different laser wavelengths, the emission powers of at least two laser light sources having different laser wavelengths are set. One light receiving element to be monitored, signal switching means for switching the output path of the output signal of the light receiving element, and an amplifier for amplifying the output signal from the signal switching means are provided, and the laser wavelength monitored by the light receiving element is set. Based on the above, the signal switching means can select whether to output the output signal of the light receiving element as it is or to output it via the amplifier. 6. The optical disc information recording apparatus according to claim 1, wherein the signal switching means is switching-controlled by a signal from an external control device. 7. In an optical disc information recording apparatus capable of writing information on at least two optical discs having different laser wavelengths, emission powers of at least two laser light sources having different laser wavelengths are set. It has one light receiving element to monitor,
7. The optical disc information recording apparatus according to claim 6, wherein the output signal of the light receiving element is corrected to a signal level that matches the resolution of the optical disc designated by the control device.