JP2710725B2 - Optical recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

(Table of Contents) Industrial Application Field Conventional Technology (FIG. 7) Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action Embodiment (a) Description of Configuration of One Embodiment ( 2 to 4) (b) Description of processing of one embodiment (FIGS. 5 and 6) (c) Description of another embodiment Effect of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording device for optimally controlling the write performance of a laser light source used in an optical disk device or the like.

In an optical disk device (including a magneto-optical disk device), a laser printer, and the like, reading, writing, and writing of information are performed using a laser light source.

In an apparatus that performs writing using such a laser light source, it is necessary to set the write conditions such as the write power and the write pulse width to optimum values so that the laser light source emits light with predetermined write performance. is there.

[0005]

2. Description of the Related Art FIG. 7 is an explanatory diagram of the prior art. As shown in FIG. 7, in an optical disk (magneto-optical disk) device,
A laser diode 100 is provided on an optical head 10 and a laser diode 1
By irradiating the light of No. 00 through the half mirror 103 and the objective lens 102, information is recorded (pits are formed), and changes in properties (light quantity, polarization plane, etc.) of the reflected light are detected by a detector (light detection). Device 101 reproduces information.

In this optical disk device, when data is written, the written data is read (referred to as "verify read") to check whether or not the data has been written normally after the write operation.
(Error correction code) processing allows a certain amount of data
Errors can be remedied.

However, as the number of data errors increases,
Even if the ECC process is performed, the data error may not be completely corrected. In such a case, a replacement area (alternate block) provided at a certain position of the optical disc medium 20 may be replaced with a new one.
The written data is rewritten and rescued, and this is called replacement processing.

The control unit 44 controls the laser diode 100
The write pulse width and the write power, which are the write conditions, are set in the write circuit 42 for driving the laser diode 100, and the laser diode 100 is driven under such conditions according to the write signal.
If the write power and write pulse width deviate from the optimal values,
An appropriate write operation is not performed, and it is determined that a write operation has not been performed normally at the time of verify read, and replacement processing is performed more frequently.

Since the number of replacement blocks is limited,
If the replacement process is performed frequently, the replacement blocks are exhausted, and the medium 20 used for normal recording cannot be written even though the area of the medium 20 has not been used up.
It is very useless.

If the write power and the write pulse width deviate from the optimum values at the time of writing, even if it is determined that the data can be normally written at the time of the verify / read operation, there is a possibility that the data was written at the margin of the margin, and the medium changes over time. However, if the surface of the medium increases, data errors increase when reading or writing after a lapse of time, and even when ECC processing is performed, the data errors may not be completely corrected.
Data that could have been written normally cannot be read later, causing a problem.

Conventionally, the optimum value of the write condition is uniquely determined by a test or the like at the time of design and manufacture, and is set as a parameter in firmware.

[0012]

However, the prior art has the following problems. There is a variation in the performance of the circuit system and optical system between the devices, and the optimum light value differs for each device, and the set light conditions deviate from the actual optimum values for each device, and the specified light performance is exhibited. Can not.

[0013] By measuring the light optimum value of each device,
Although a method of setting with a dip switch or the like is also conceivable, it is difficult to automate the work, and it becomes complicated. Therefore, an object of the present invention is to provide a light control method for a laser device that can easily perform writing under optimum write conditions even if the devices vary.

[0014]

FIG. 1 is a diagram illustrating the principle of the present invention. The present invention achieves the above object by the following:
Configured. (1): Laser light source 100 and laser light source 10
0 and a drive circuit 42
By changing the condition value of the laser light source,
A measuring unit that measures the light condition value at which
The optimum write condition value measured by the measurement unit is stored.
Nonvolatile memory 45 and the nonvolatile memory 45
When the power is turned on, the nonvolatile memory
The optimal write condition value is read from the volatile memory 45,
Control to load the optimum write condition value to AM
During the write operation, based on the optimum write condition value of the RAM.
To drive the drive circuit 42 so that the laser light source 10
0 is controlled to perform a predetermined write operation by driving 0.
And a control unit 44 .

(2): In the above (1), the light
The condition value was a write power value . (3): In (1), the write condition value is
Unit pulse width .

(4): Any one of the above (1) to (3)
Oite, the optimum write condition value stored in the nonvolatile memory 45, a correction value for the default writing condition values set in the apparatus, the control unit 44, the default writing by the correction value <br/> Obtained by changing the condition value
The optimum write condition value is loaded into the RAM .

(5): Any one of the above (1) to (4)
In this case, the optical recording device is connected to the laser light source 10.
0 writes information on an optical information storage medium by, and an optical information recording and reproducing apparatus for reading.

(6): In the above (5), the write condition value at which the write performance is optimal is determined by the C of the reproduced signal obtained by reading the information after writing the information with the laser light source.
The write condition value at which the NR was maximized was set .

(7) In the above (5), a write condition value at which the write performance is optimized is set such that a bit error rate of a reproduced signal obtained by reading information after writing information with the laser light source is minimized. and light condition value
Was .

(8): Any one of the above (5) to (7)
In this case, the measuring unit is a light for which the light performance is optimized.
Condition values for a plurality of zones of the optical information storage medium .
Measured, and stores the optimum write condition value of each zone in a nonvolatile memory, the control unit 44, the laser light source 100
The drive circuit 42 is driven based on the optimum write condition value of the zone according to the write position of the optical information storage medium.
It works .

(9) Any one of the above (5) to (7)
The measurement unit may be configured to optimize the light performance.
The site condition value, measured for a plurality of kinds of the optical information storage medium, and stores the optimum write condition value for each medium in the nonvolatile memory 45, the control unit 44, the laser
The drive circuit 42 is driven based on an optimum write condition value of the light source 100 according to the type of the optical information storage medium.
I did it .

(10): any one of the above (5) to (7)
In the measuring section, the light condition values the write performance is optimized is measured for a plurality of ambient temperature, and stores the optimum write condition value of the respective ambient temperature in the nonvolatile memory 45, the control unit 44 drives the drive circuit 42 based on the optimum write condition value corresponding to the environmental temperature .
I did it . (11): In the above (4), the default light
The condition value is provided separately from the nonvolatile memory 45 .
Stored in ROM .

[0023]

In the above (1), the measuring section is driven by the driving circuit 42.
Is changed , the write condition value at which the light performance of the laser light source 100 is optimized is measured, and the measured optimum write condition value is stored in the nonvolatile memory 45. The control unit 44 reads the optimum write condition value of the nonvolatile memory 45 and stores the read value in the RAM.
To load . Then, the control unit 44 sets the drive circuit 42 in front.
Since the optimum write condition value read from the RAM is controlled, even if the write performance of each device differs, the write control can be performed with the optimum write condition value of the device, the write performance can be improved, and automation is supported it can. Also non-volatile
Since the memory was used, there was a variation in each device.
Can easily and accurately set the optimum write condition value,
It is possible to automate work without complicated work.
Light strips obtained by measuring each device in volatile memory
Value is stored, so that the optimum write conditions
Can always be stored in its own memory, power off
Also, the optimum write condition value is not lost. In addition,
At power-on, write condition values are expanded in RAM
When the write command comes, it can respond immediately.

In the above (2) and (3), since the write condition value is a write power value or a write pulse width, the write control can be performed with the optimum write power or pulse width of the device.

In the above (4), the optimum write condition value stored is a correction value for the default write condition value set in the apparatus, and the control unit 44 determines the default write condition value based on the read correction value. To change
Since the optimum write conditions are loaded into the RAM, the optimum write control corresponding to the performance of each device can be performed.

In the above (5), since the optical recording device is an optical information storage / reproduction device for writing / reading information to / from the optical information storage medium by the laser light source 100 , the optical recording device corresponds to the performance of each information storage / reproduction device. Optimal write control becomes possible, and write / read performance is improved.

In the above (6) and (7), the write condition value at which the write performance is optimal is the write condition value at which the CNR of a reproduced signal obtained by reading information after writing information with the laser light source 100 is maximized. Alternatively, since the write condition value is such that the bit error rate of the reproduced signal is minimized, optimal write control corresponding to the performance of each information storage / reproducing device can be performed, and the write / read performance is improved.

In the above (8), the measuring section measures the write condition value at which the write performance is optimum for a plurality of zones of the optical information storage medium , and determines the optimum write condition value of each zone. The data is stored in the nonvolatile memory 45 . Soshi
Since the control unit 44 drives the drive circuit 42 based on the optimum write condition value of the zone according to the write position of the optical information storage medium of the laser light source 100 , the control unit 44 responds to the write position of the optical information storage medium. Writing can be performed under optimum write conditions, and optimum write control corresponding to the performance of each information storage / reproducing device can be further performed, thereby improving write / read performance.

In the above (9), the measuring section measures the write condition value for optimizing the write performance for a plurality of types of the optical information storage media , and determines the optimum write condition value for each medium in the nonvolatile memory. Stored in the memory 45, and the control unit 44
Since the drive circuit 42 is driven based on the corresponding optimum write condition value according to the type of the optical information storage medium, the optimum write control according to each information storage / reproducing device and the medium to be used can be performed. Performance is improved.

In the above (10), the measuring section sets the write condition value at which the write performance is optimal for a plurality of environmental temperatures .
Then , each environmental temperature optimum write condition value is stored in the nonvolatile memory 45 . Then, the control unit 44
Depending on the environmental temperature, the corresponding optimum write condition value based on
Then, the drive circuit 42 is driven, so that optimum write control according to each information storage / reproduction device and the use environment temperature can be performed, and the write / read performance is improved. The above (11)
Then, the default write condition value is stored in the nonvolatile memory
45 is stored in a ROM provided separately. in this way
This reduces the required capacity of the nonvolatile memory 45.
Can be eliminated.

[0031]

【Example】

(a) Description of Configuration of One Embodiment FIG. 2 is a configuration diagram of one embodiment of the present invention, and FIG. 3 is a rear view of one embodiment of the present invention, showing a magneto-optical disk drive.

In FIG. 2A, reference numeral 1 denotes a magneto-optical disk drive, 10 denotes a movable optical head which irradiates the optical disk 20 with light to perform writing and reading, 10a
Denotes a fixed optical head, which houses fixed parts such as a light emitting unit (laser diode) 100, an optical system (half mirror 103, etc.), a light receiving unit 101, etc., 11 denotes a VCM (voice coil motor) coil, and an optical head An optical head 10 and a VCM coil 11 are provided for driving the optical disk 10 in the radial direction of the optical disk 20 and for a positioner (movable part) 12.

13 is an inner peripheral stopper of the positioner 12, 14 is an outer peripheral stopper of the positioner 12,
Reference numeral 15 denotes a spindle motor that rotates the optical disk 20, and reference numeral 16 denotes an external magnet that applies a magnetic field to the optical disk 20 to enable writing.

An optical disk cartridge 2 has an optical disk 20 and is attached to and detached from the magneto-optical disk device 1. In FIG. 2 (B), reference numeral 17 denotes a light emitting unit which is constituted by an LED (light emitting diode), is provided on the positioner 12, and emits light to the semiconductor position detecting element 18, and 18 denotes a semiconductor position detecting element (PSD). This is provided in parallel with the movable path of the positioner 12, detects the light of the light emitting section 17 on the light receiving surface 18a, and generates a current output corresponding to the position (absolute position) of the positioner 12.

In FIGS. 2B and 3, reference numeral 11a denotes VC
An M magnet, which constitutes a VCM (straight motor) together with the VCM coil 11, 12a is a space portion, which allows the positioner 12 to move without the spindle motor 15 being in the way, and 12b is a connecting portion. And V
The CM coil 11 and the optical head 10 are connected, and the space 1
2a.

As shown in the back view of FIG.
A semiconductor position detecting element 18 is fixed on the back surface side opposite to the light irradiation direction of 0, and a light emitting section 17 is provided near the optical head 10 of the positioner 12.

As described above, since the light emitting section 17 is provided independently, the position can be detected even when the optical head 10 does not emit light, the seek operation can be performed, the light emission amount can be sufficiently obtained, and the accurate position detection can be performed. Makes it possible to perform a seek operation.

Moreover, since the optical head 10 is provided on the rear surface side, there is no possibility that the position of the optical head 10 is erroneously detected due to stray light when the optical head 10 emits light. Further, the optical head 10 has only movable parts such as an objective lens and a track / focus actuator,
The light emitting unit, the light receiving unit, and the optical system are provided in the fixed optical head 10a, and the fixed optical head 10a and the movable optical head 10 are optically coupled, so that the movable optical head 10 can be reduced in weight and can be driven at high speed. Become.

Further, since the positioner 12 is formed so as to straddle the spindle motor 15 from the side, the apparatus can be downsized by using a high-speed VCM. FIG. 4 is a block diagram of one embodiment of the present invention.

In the figure, the same elements as those shown in FIGS.
Are indicated by the same symbols.
A voltage conversion circuit, which is provided at both ends of the semiconductor position detecting element 18.
Current output I₁, I_TwoIs the voltage V₁, V_TwoTo convert to
32 is a difference circuit, and the voltage V ₁From the voltage V_Two,
33 for generating a position signal;
Tal) converter that converts analog position signals to digital
The signal is converted into a signal and input to the control unit 44.

Reference numeral 34 denotes a DA (digital / analog) converter for converting a digital drive signal of the control unit 44 into an analog drive signal, and reference numeral 35 denotes a difference circuit for subtracting the drive signal from the position signal to obtain a position error signal. Is a phase compensation circuit, which advances the high frequency component of the position error signal and compensates the phase, and 37 is a VCM drive amplifier, which outputs the VCM coil of the positioner 12 by the output of the phase compensation circuit 36. 11 is driven by current.

Numeral 38 denotes a track servo control unit which controls the optical head 1 based on a track error signal TES generated by the fixed optical head 10a from the reflected light of the movable optical head 10.
Servo control of 0 track actuator, 3
Reference numeral 9 denotes a focus servo control unit which servo-controls a focus actuator of the optical head 10 by a focus error signal FES generated by the fixed optical head 10a from the light emitted from the optical head 10.

Reference numeral 40 denotes a DA converter.
A switch 41 for converting the write power value of the laser diode 100 into an analog drive amount, a switch 41 for outputting the analog drive amount to the laser diode drive circuit 42 under the control of the control unit 44, and a laser diode drive circuit 42. The A / D converter 43 drives the laser diode 100 with an analog drive amount, converts the monitor light amount of the laser diode 100 into a digital value, and inputs the digital value to the control unit 44.

Reference numeral 44 denotes a control unit which is constituted by a microprocessor (MPU) and performs seek control, read / write control, and the like by executing a program in accordance with an instruction from a host, and 45 denotes a nonvolatile memory, which is an EEPROM.
(Electrically erasable programmable read-only memory), which stores parameters, etc.
Reference numeral 46 denotes a read circuit for reproducing read data from a reproduced signal from the detector 101 of the fixed head 10a.
This is to perform CC processing and output.

In this embodiment, the VCM coil 11 can be driven by a position error signal which is a difference between the drive signal of the control unit 44 and the position signal. That is, the control unit (hereinafter, referred to as a processor) 44 calculates the output value X for the target position r given from the host, and sends the drive signal X to the DA converter 34.
And a position error signal between the position signal of the semiconductor position detecting element 18 generated from the difference circuit 35 and the drive signal X of the DA converter 34 is given to the VCM coil 11 via the phase compensation circuit 36 and the VCM drive amplifier 37. Move, seek.

When the position signal from the AD converter 33 reaches the target position, the processor 44 determines that the target position (track) has been positioned, determines that the seek has been completed, and ends the seek operation.

After that, the processor 41 turns on the servo control of the track servo control section 38 and the focus servo control section 39 and performs reading / writing by the optical head 10. (b) Description of Processing in One Embodiment FIG. 5 is an explanatory diagram of one embodiment of the present invention, and FIG. 6 is a processing flowchart of one embodiment of the present invention.

In FIG. 5, the same components as those described with reference to FIGS. 2 to 4 are indicated by the same symbols, and 5 is a spectrum analyzer, which is a spectrum of an analog reproduction signal before pulse shaping of the read circuit 46. Analyze
It measures CNR (Carrier Noise Ratio).

Reference numeral 6 denotes a terminal for inputting the optimum measured value to the magneto-optical disk drive 1, and 7 denotes a tester for setting the write power set value to the processor 44 of the magneto-optical disk drive 1 and starting up. , 8 are personal computers, and the spectrum analyzer 5,
The terminal 6 and the tester 8 are controlled.

In this embodiment, when the apparatus is started before shipment, the spectrum analyzer 5, the terminal 6, and the tester 8 are connected to the magneto-optical disk apparatus 1, the optimum write power is measured, and the optimum write power is measured in a nonvolatile manner. This is written into the memory 45, and will be described with reference to the measurement processing flow chart at the time of starting the apparatus in FIG.

Under the control of the personal computer 8, the tester 7 sets the write power setting value (default value -2 mW) to the processor 44 as an initial value and starts up.

The tester 7 calculates the current write power value +0.
2 mW is given to the processor 44 as a write power set value, and the processor 44 outputs this to the DA converter 40 and gives it to the laser drive circuit 42. The laser diode 100 is driven at the write power design value to write data. To write data to the optical disk 20.

Next, the processor 44 instructs the laser drive circuit 42 to read, drives the laser diode 100 with read power, and causes the read circuit 46 to read data.

The read reproduction waveform at this time is analyzed by a spectrum analyzer, a CNR (carrier noise ratio) is measured, and the measured value is notified to the personal computer 8.

The tester 7 has a write power setting value
It is determined whether or not the value has reached the default value +2 mW (measurement limit value). If not, the process returns to the step, and if so, the personal computer 8 is notified of the end of measurement.

The personal computer 8 compares the measured 20 CNRs to determine the write power at which the CNR is maximized. The optimum write power value measured from the terminal 6 is output to the processor 44, written into the nonvolatile memory 45, and saved.

In this way, various write power values are set from the measuring device, the write power value at which the CNR becomes maximum is measured by the measuring device, and written in the nonvolatile memory 45 of the magneto-optical disk device 1.

Also, since the data is written to the nonvolatile memory 45,
Even if the power is turned off, the optimum write power value is not lost. Next, a process when the power is turned on will be described with reference to FIG.

When the power is turned on, the processor 44 loads the optimum write power value stored from the nonvolatile memory 45 into the built-in RAM. The processor 44 sets the loaded optimal write power value in the write condition table.

Thereafter, when a write command arrives, the processor 44 converts this optimum write power value into a DA converter 4 value.
0, and the laser drive circuit 42 drives the current value of the laser diode 100 with the write power value.

As described above, the nonvolatile memory 45 is provided in the magneto-optical disk device 1 to store the write power value which maximizes the CNR of the reproduction signal automatically measured by the measuring device in advance,
When the power is turned on, the read power is set as the write power value, so that the write can be performed with the optimum write power for each device, and the read / write performance is improved.

(C) Description of Another Embodiment In addition to the above-described embodiment, the present invention can be modified as follows. Invented in the magneto-optical disk device, the optical disk device,
The present invention can be applied to other laser devices such as a laser printer.

Although the write power has been described as the write condition, a write condition value such as a write pulse width can be used. Although the write power value is stored, the RO
A default value of the write power may be stored in M, the correction value may be stored in a non-volatile memory, and the optimum write power value may be obtained from the correction value and the default value when the power is turned on.

As the optimum write condition, the CN of the reproduction signal
Although the write condition value at which R is the maximum is used, a write condition value at which the bit error rate of the reproduced signal is minimized may be measured.
The write condition value that minimizes the error rate may be measured.

Although the measurement is performed at one position on the optical disk, the optimum write condition values at the innermost and outermost two points of the medium are measured, and both are stored, and according to the seek position,
A corresponding optimum write condition value may be selected.

Since the write condition value changes depending on the medium type and the environmental temperature of the optical disk, the optimum write condition value is measured and stored for various media and temperatures, and the optimum write condition value is stored depending on the type of the medium used and the environmental temperature. An optimum write condition value may be selected.

The present invention has been described with reference to the embodiments.
Various modifications are possible within the scope of the present invention, and these are not excluded from the scope of the present invention.

[0068]

As described above, according to the present invention,
The following effects are obtained. The optimum write condition value of the device is measured and stored in advance, and is read and set as a write condition at the start of operation. Therefore, even if the write performance of each device is different, the optimum write condition value of the device is used. Light control can be performed, and light performance can be improved.

Further, since measurement and writing are performed, automation can be performed. Since the measured optimum value is stored in the non-volatile memory, the optimum value can be retained even when the power is turned off, and the accurate write control can always be performed without losing the optimum value. Since non-volatile memory is used, variations in individual devices
Easily and accurately set the optimal lighting conditions
Can be automated without complicated operations.
it can. In the non-volatile memory, the lines obtained by
Since the light condition values are stored, the optimum light conditions
Can be kept in its own memory at all times, power off
However, the optimum write condition value is not lost. : When the power of the device is turned on, the write condition value is stored in RAM.
Open to respond immediately when a write command is received
it can.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a rear view of one embodiment of the present invention.

FIG. 4 is a block diagram of one embodiment of the present invention.

FIG. 5 is an explanatory view of one embodiment of the present invention.

FIG. 6 is a processing flowchart of an embodiment of the present invention.

FIG. 7 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magneto-optical disk drive 2 Optical disk cartridge 10 Optical head 11 VCM 12 Positioner 20 Optical disk 42 Laser drive circuit 44 Control part 45 Non-volatile memory 46 Read circuit 100 Laser diode

Claims (11)

(57) [Claims] And 1. A laser light source, a drive circuit for driving the laser light source, by changing the write condition value of the drive circuit, the laser
ー Measure the light condition value that optimizes the light performance of the light source.
Be stored a measuring unit that, the optimum write condition value measured by the measuring section
A non-volatile memory, and provided separately from the non-volatile memory.
And the optimum write condition from the nonvolatile memory when the power is turned on.
The optimum write condition value in the RAM.
Control during the write operation, based on the optimum write condition value of the RAM.
Driving the laser circuit to drive the laser light source to perform a predetermined write operation.
Optical recording instrumentation, characterized in that it comprises a control unit, at least for controlling that
Place . 2. The optical recording apparatus according to claim 1, wherein said write condition value is a write power value. 3. The optical recording apparatus according to claim 1, wherein said write condition value is a write pulse width. 4. An optimum write condition value stored in the nonvolatile memory is a correction value for a default write condition value set in the apparatus, and the control unit controls the correction value based on the correction value . Optimum obtained by changing the default light condition value
4. The optical recording apparatus according to claim 1 , wherein a write condition value is loaded into a RAM.
Place . Wherein said optical recording apparatus, the write information on an optical information storage medium with a laser light source, reads claim 1 or 2 or 3 or 4 optics, wherein the an optical information recording and reproducing apparatus Recording device . 6. The write condition value at which the write performance is optimized is a write condition value at which a CNR of a reproduced signal obtained by reading information after writing information by the laser light source is maximized. Item 5. Optical recording according to item 5.
Equipment . 7. A write condition value at which the write performance is optimized is a write condition value at which a bit error rate of a reproduced signal obtained by reading information after writing information by the laser light source is minimized. Claim 5
The optical recording device as described in the above . 8. The measuring unit according to claim 1 , wherein the light performance is optimized.
The write condition value in a plurality of zones of the optical information storage medium.
And the optimum write condition value of each zone is stored in the non-volatile memory, and the control unit is configured to perform the control based on the optimum write condition value of the zone according to the write position of the optical information storage medium of the laser light source. The optical recording device according to claim 5 , wherein the driving circuit drives the driving circuit.
Recording device . 9. The measurement unit according to claim 1 , wherein the light performance is optimized.
Measuring the write condition values for a plurality of types of the optical information storage media, storing the optimum write condition values for each of the media in the nonvolatile memory, and controlling the laser light source.
Wherein the optical information based on the optimum write condition value according to the type of storage medium, an optical recording apparatus according to claim 5 or 6 or 7, wherein the driving the driving circuit. Wherein said measuring unit, a write condition values the write performance is optimized is measured for a plurality of ambient temperature,
6. The storage device according to claim 5, wherein the optimum write condition value of each environmental temperature is stored in the nonvolatile memory, and the control unit drives the drive circuit based on the optimum write condition value corresponding to the environmental temperature. Or the optical recording device according to 6 or 7
Place . 11. The non-volatile memory according to claim 1, wherein the default write condition value is
Stored in a ROM provided separately from the non-volatile memory.
The optical recording apparatus according to claim 4, wherein: