JP2007328844A - Optical disk recording/reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide good recording quality all around the periphery by setting a target with characteristic changes in inner and outer peripheries of an optical disk taken into consideration to execute running OPC. <P>SOLUTION: A system controller 10 executes test writing on the outer peripheral side of an optical disk 1 by laser power decided by OPC implementation on the inner peripheral side of the optical disk 1 to measure an asymmetry value, calculates an approximate equation based on a difference between the asymmetry value of the laser power decided by the OPC implementation and the asymmetry value measured in the test writing, and sets an asymmetry value which becomes a target in the writing position of the optical disk 1 according to the approximate equation as occasion demands to execute running OPC. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical disc recording / reproducing apparatus including a control unit that performs running OPC (Optimum Power Control) for controlling laser power during recording when recording on an optical disc by an optical pickup.

In an optical disc recording / reproducing apparatus capable of recording data on an optical disc such as a DVD (Digital Versatile Disk), asymmetry (asymmetric) of a recording portion formed on the optical disc by the laser power of an optical pickup that irradiates the optical disc with laser light Is used to calculate the optimum laser power for the optical disk. That is, in such an apparatus, data for trial writing is recorded in a power calibration area (PCA: Power Calibration Area) provided on the inner circumference side of the optical disk while changing the laser power of the optical pickup. For example, a laser power whose asymmetry of the recording portion of the data for trial writing is zero is acquired, and the data is recorded using this as the optimum laser power at the time of recording.

  However, it is difficult to keep the sensitivity to laser light constant due to the manufacturing method (for example, non-uniformity of the reflective film layer, etc.), and in particular, the sensitivity characteristic of the optical disc is in the circumferential direction. There is a tendency to fluctuate.

  Therefore, as a means to cope with such changes in sensitivity characteristics and ambient temperature changes, by performing a running OPC for controlling the laser power during recording when recording on the optical disk by an optical pickup, the quality of writing on the optical disk is improved. Uniformization is performed (see, for example, Patent Document 1).

The one described in Patent Document 1 is for recording by changing the target β of the running OPC according to the recording radial position according to the optical disk to be recorded. Specifically, in ZoneCLV, each recording linear velocity is: Good recording characteristics are obtained by recording in place of the target β value suitable for each recording linear velocity.
JP 2003-228832 A

  However, the conventional running OPC including the above-mentioned Patent Document 1 has the following problems. That is, in the continuous writing type running OPC as described above, the target β is determined using reflected light as a parameter, but changes in reflectance characteristics between the inner periphery and the outer periphery of the optical disc are not taken into consideration. Also, in the readback type OPC, the asymmetry value is measured by reading back the place where writing is performed, and the asymmetry value is controlled to be constant. Asymmetry characteristics at the inner and outer circumferences of the optical disc Changes are not taken into account. That is, although the thing of patent document 1 is changed into the target (beta) value suitable for each recording linear velocity, the changed (beta) value itself is not the value which considered the reflectance characteristic change or the asymmetry characteristic change. .

  For this reason, when writing is performed from the middle of the optical disk, the characteristics immediately after the start of writing cannot be grasped, and the recording quality may be deteriorated.

  The present invention was devised to solve such problems, and the purpose of the present invention is to set the target in consideration of the characteristic change at the inner and outer circumferences of the optical disc and to execute the running OPC, so that the entire circumference is achieved. It is another object of the present invention to provide an optical disc recording / reproducing apparatus capable of obtaining good recording quality.

  In order to solve the above problems, an optical disc recording / reproducing apparatus of the present invention is an optical disc recording / reproducing apparatus provided with a control unit that performs running OPC for controlling laser power during recording when recording on an optical disc by an optical pickup. The control unit performs test writing at the outer peripheral side of the optical disc with the laser power determined by the OPC execution on the inner peripheral side of the optical disc, measures the asymmetry value, and the asymmetry value at the laser power determined by the OPC execution. And calculating the approximate expression of the asymmetry value from the difference between the asymmetry value measured by the test writing and setting the target asymmetry value at the writing position of the optical disc as needed according to the approximate expression, and executing the running OPC. It is characterized by.

  In the optical disk recording / reproducing apparatus, the recording laser power is optimized (OPC) before data is recorded on the optical disk. That is, power calibration is performed in advance and test writing is performed, and the optimum laser power for subsequent recording is determined. This OPC is performed by recording data with different recording laser power in a power calibration area (PCA) provided on the inner circumference side of the optical disk and reproducing the recorded data.

  The control unit performs test writing on the outer circumference side of the optical disc with the laser power determined by the execution of the OPC and measures an asymmetry value, and determines the asymmetry value at the laser power determined by the OPC execution and the test writing. An approximate expression of the asymmetry value is calculated from the difference from the measured asymmetry value. That is, if there is no change in reflectance characteristics or asymmetry characteristics on the inner and outer circumferences of the optical disc, the two asymmetry values should match, and if there is a change in these characteristics, the difference between the two asymmetry values. Appears as Accordingly, by calculating an approximate expression that takes this difference into account and setting the target asymmetry value of the running OPC using this approximate expression, it is possible to set a target that takes into account changes in reflectance characteristics and asymmetry characteristics.

  Specifically, the asymmetry value at the laser power determined by the OPC execution is A1, the asymmetry value measured by the test writing is A2, and from the OPC execution position on the inner peripheral side of the optical disk to the test write position on the outer peripheral side. When the distance is X, the approximate expression A is [A = (A2−A1) / X + A1].

  The control unit sets a target asymmetry value at the writing position of the optical disc as needed according to the approximate expression A, and performs running OPC. For example, when the writing position of the optical disc is a distance X1 from the OPC execution position on the inner peripheral side of the optical disc to the outer peripheral side, the asymmetry value A (X1) that becomes the target at the start of writing is [A (X1) = X1 (A2-A1) / X + A1]. The DVD standard stipulates that this asymmetry value must be within the range of -0.05 to +0.15.

  According to the optical disk recording / reproducing apparatus of the present invention, the control unit performs the test writing every time data is written to the optical disk, measures the asymmetry value, and determines the laser power determined by the OPC. Alternatively, the approximate expression A may be calculated each time from the difference between the asymmetry value at and the asymmetry value measured by the test writing. As a result, the approximate expression A corresponding to the operating environment of the apparatus and the state of the optical disk itself is calculated each time, so that a more accurate target asymmetry value can be set.

  The optical disk recording / reproducing apparatus of the present invention is an optical disk recording / reproducing apparatus provided with a control unit that performs running OPC for controlling laser power during recording when recording on an optical disk by an optical pickup. Test writing is performed at a plurality of locations in the radial direction of the disk with the laser power determined by performing OPC on the inner circumference side, and asymmetry values are respectively measured. The asymmetry value at the laser power determined by performing OPC and Based on the respective asymmetry values measured in the test writing, an approximate expression of the asymmetry value is calculated, and the target asymmetry value at the writing position of the optical disc is set as needed according to the approximate expression to execute the running OPC. It is characterized by that. That is, by performing test writing at a plurality of locations in the disk radial direction, an approximate expression with higher accuracy can be calculated.

  The optical disc recording / reproducing apparatus of the present invention is an optical disc recording / reproducing apparatus provided with a control unit that performs running OPC for controlling the laser power during recording by the amount of reflected light from the optical disc when recording on the optical disc by an optical pickup. The control unit performs test writing on the outer peripheral side of the optical disc with the laser power determined by performing the OPC on the inner peripheral side of the optical disc, measures the amount of light reflected from the optical disc, and determines the laser power determined by the OPC implementation. An approximate expression of the reflected light quantity is calculated from the difference between the reflected light quantity at the test and the reflected light quantity measured in the test writing, and the target reflected light quantity at the writing position of the optical disc is set as needed according to the approximate expression, and the running OPC is performed. It is characterized by implementing. That is, in an apparatus that performs running OPC that uses reflected light, the reflected light amount is measured instead of the asymmetry value, and an approximate expression of the reflected light amount inside and outside the optical disk is calculated in the same manner. By setting an OPC target, it is possible to set a target in consideration of changes in reflectance characteristics.

  According to the present invention, test writing is performed on the outer periphery side of the optical disk with the laser power determined by the OPC execution to measure the asymmetry value, and measurement is performed with the asymmetry value at the laser power determined by the OPC execution and the test writing. By calculating the approximate expression of the asymmetry value from the difference from the asymmetry value, and setting the target asymmetry value of the running OPC using this approximate expression, the reflectance characteristic change and the asymmetry characteristic change are made over the entire circumference of the optical disc. Since the target considered can be set, good recording quality can be obtained over the entire circumference of the optical disk.

  In addition, according to the present invention, each time data is written to the optical disk, test writing is performed to measure the asymmetry value, and an approximate expression is calculated each time. An approximate expression according to the state can be calculated, and a more accurate target asymmetry value can be set. Thereby, the best recording quality can be obtained over the entire circumference of the optical disk.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a system configuration of a DVD recorder which is an embodiment of an optical disk recording / reproducing apparatus of the present invention.

  That is, the output of the optical pickup 3 that reads data from the loaded optical disk 1 and records the data is connected to the digital signal processing circuit 7 via the RF amplifier 5, and the output of the digital signal processing circuit 7 is It is connected to a laser driver 8 that controls laser output at the time of data writing and reading by the optical pickup 3. The output of the servo processing circuit 9 is connected to a feed motor 4 for moving the optical pickup 3 in the radial direction of the optical disk 1 and a spindle motor 2 for rotationally driving the optical disk 1. These digital signal processing circuit 7 The servo processing circuit 9 is bidirectionally connected to a system controller 10 that controls the operation of the entire recorder.

  The digital signal processing circuit 7 is connected to, for example, a DRAM 6 as a buffer for temporarily storing data at the time of writing to the disk or at the time of reproducing, and converts the digital data into analog data to convert the digital data into a CRT. A D / A conversion circuit 12 that outputs to the display device 21 is connected.

  The system controller 10 is bi-directionally connected to an EEPROM 11 for storing unique information such as parameters of the optical disc 1 and laser power parameters. The system controller 10 is connected to a receiver 14 that receives an infrared signal from a remote controller 18 having a numeric keypad and various function keys.

  The digital signal processing circuit 7 converts the RF signal output from the RF amplifier 5 into digital data and then performs signal demodulation processing and error correction processing according to the data format of the optical disc 1 to store data generated in the DRAM 6. The stored data is read out and output to the D / A conversion circuit 12.

  The system controller 10 reads control information (file information, etc.) from a predetermined area of the optical disk 1 when the optical disk 1 is loaded, records it in a predetermined area of the DRAM 6, and thereafter stores the control information stored in the predetermined area of the DRAM 6. Based on this, playback processing is executed. In addition, the system controller 10 performs running OPC for controlling the laser power during recording when the optical pickup 3 records on the optical disc 1.

  Here, in the present embodiment, the system controller 10 sets a target in consideration of various characteristics on the inner peripheral side and the outer peripheral side of the optical disc to be recorded when the running OPC is performed. Hereinafter, the target setting process will be described with specific examples.

  2 and 3 are flowcharts showing the target setting processing operation of the first embodiment, and FIG. 4 is an explanatory diagram of an approximate expression. However, FIG. 2 is a flowchart showing the processing operation for obtaining the approximate expression, and FIG. 3 is a flowchart showing the processing operation for performing the running OPC using the obtained approximate expression. The processing operation of the first embodiment will be described below with reference to the flowcharts shown in FIGS. 2 and 3 and the explanatory diagram shown in FIG.

  In the optical disk recording / reproducing apparatus 1, the recording laser power is optimized (OPC) before data is first recorded on the optical disk 1. That is, power calibration is performed in advance and test writing is performed, and the optimum laser power for subsequent recording is determined (step S1). This OPC is performed by recording data having different recording laser powers in a power calibration area (PCA) provided on the inner peripheral side of the optical disc 1 and reproducing the recorded data. The system controller 10 measures the asymmetry value at the laser power determined by the OPC implementation, and stores the inner circumference side asymmetry value in the EEPROM 11 (step S2).

  Next, the system controller 10 performs test writing on the outer peripheral side of the optical disc with the laser power determined by the execution of this OPC (step S3), measures the asymmetry value, and stores the outer asymmetry value in the EEPROM 11. (Step S4).

  Next, the system controller 10 calculates an approximate expression A of the asymmetry value from the difference between the inner circumference side asymmetry value at the laser power determined by the OPC execution and the outer circumference side asymmetry value measured by the test writing (step S5). ). This approximate expression A is stored in the EEPROM 11.

Specifically, the inner circumference asymmetry value at the laser power determined by the OPC execution is A1, the outer circumference asymmetry value measured by the test writing is A2, and the test writing from the OPC execution position on the inner circumference side of the optical disk to the outer circumference side. When the distance to the position is X, the approximate expression A is
A = (A2-A1) / X + A1
It becomes.

  FIG. 4 is a graph showing this approximate expression A. In this graph, the vertical axis indicates the asymmetry value, and the horizontal axis indicates the distance X from the OPC execution position Z1 on the inner peripheral side of the optical disk to the test writing position Z2 on the outer peripheral side. Specifically, the OPC execution position Z1 on the inner peripheral side of the optical disc is at a position of about 30 mm from the center of the optical disc 1, and the test writing position Z2 on the outer peripheral side is a position of about 60 mm from the center of the optical disc 1. Therefore, the distance X is about 30 mm.

  Here, when there is no change in reflectance characteristics or asymmetry characteristics on the inner and outer circumferences of the optical disc, both asymmetry values A1 and A2 should match, and the approximate expression A in that case is shown in FIG. ), (B) As shown by the alternate long and short dash line, it becomes a horizontal straight line with no inclination. On the other hand, when these characteristics change, both asymmetry values A1 and A2 become different values, and the approximate expression A in that case is a straight line having an inclination as shown by the solid line in FIGS. 3 (a) and 3 (b). Become.

  When the approximate expression A is calculated in this way and stored in the EEPROM 11 and a write instruction is input from the middle of the disk (step S11), the system controller 10 uses the approximate expression A to execute the target of the running OPC. An asymmetry value is calculated and set (step S12).

For example, when the writing position of the optical disc is a distance X1 from the OPC execution position Z1 on the inner peripheral side of the optical disc to the outer peripheral side, the asymmetry value A (X1) as a target at the start of writing is
A (X1) = ΔX (A2−A1) / X + A1
It becomes.

For example, when A1 is 0.1, A2 is 0.15, and the writing position (writing start position) X1 is 15 mm, the target asymmetry value A (X1) at this time is ,
A (X1) = 15 (0.15-0.1) /30+0.1=0.125
It becomes. This makes it possible to set a target in consideration of changes in reflectance characteristics and changes in asymmetry characteristics.

  The system controller 10 sets the asymmetry value A (X1) = 0.125 as a target and performs running OPC while writing data to the optical disc 1 in accordance with a write instruction (step S13).

  In the system controller 10, the above-described steps S <b> 11 to S <b> 13 are performed every time there is a write instruction from the middle of the disc to the same optical disc 1. That is, every time there is a write instruction, an optimum target asymmetry value is set in accordance with the approximate expression A each time.

  In the first embodiment, when the approximate expression A is first calculated, the target asymmetry value is set according to the first calculated approximate expression A every time there is a write instruction from the middle of the disk. In this embodiment, the approximate expression A is calculated and corrected each time a write instruction is issued from the middle of the disk. The processing operation of the second embodiment will be described below with reference to the flowchart shown in FIG.

  When an asymmetry value at the laser power determined by the OPC is measured and the inner circumference side asymmetry value is stored in the EEPROM 11, a writing instruction from the middle of the disk is input (step S21). 10 performs test writing on the optical disc outer peripheral side with the laser power determined by the previous OPC (step S22), measures the asymmetry value, and stores the outer peripheral asymmetry value in the EEPROM 11 (step S23). ).

  Next, the system controller 10 calculates an approximate expression A of the asymmetry value from the difference between the inner circumference side asymmetry value at the laser power determined by the OPC execution and the outer circumference side asymmetry value measured by the test writing (step S24). ). This approximate expression A is stored in the EEPROM 11.

  Next, the system controller 10 calculates and sets the target asymmetry value A (X1) of the running OPC using the approximate expression A (step S25). Then, data is written to the optical disc 1 according to the write instruction while the running OPC is performed with the asymmetry value A (X1) set as a target (step S26).

  The system controller 10 performs the processing of the above steps S21 to S26 every time there is a write instruction from the middle of the disc to the same optical disc 1. That is, each time a write instruction is issued, the approximate expression A is calculated and the approximate expression A itself is corrected each time, so that a more optimal target asymmetry value is set each time.

  In the first embodiment, these two points are connected by a straight line based on the two asymmetry values of the inner asymmetry value measured by the OPC and the outer asymmetry value measured by the test writing. Although the approximate expression is calculated, in the third embodiment, the test writing is performed at a plurality of locations in the disk radial direction, the asymmetry values are respectively measured, and the asymmetry values at the laser power determined by the OPC execution are calculated. Then, an approximate expression is calculated based on each asymmetry value measured by test writing.

  For example, test writing is performed at two locations in the radial direction center and outer peripheral portion of the disk, and the respective asymmetry values are measured. As a result, the asymmetry value for obtaining the approximate expression becomes three values: the asymmetry value on the inner periphery side of the disc, the asymmetry value at the center portion of the disc, and the asymmetry value on the outer periphery side of the disc. Therefore, for example, as shown in FIG. 6, assuming that the asymmetry value at the inner periphery of the disk is A11, the asymmetry value at the center of the disk is A12, and the asymmetry value at the outer periphery of the disk is A13, the approximate expression A is It becomes a straight line as shown by a solid line. In other words, since the approximate expression A takes into account the asymmetry value A12 at the center of the disk, a more accurate approximate expression A in which changes in the characteristics of the disk are taken into consideration over the entire area from the inner circumference side to the outer circumference side of the disk. Can be calculated.

  In each of the first to third embodiments, an asymmetry value is set as a target for running OPC. In this embodiment, the running OPC is performed using the amount of light reflected from the optical disk as a target. That is, in the third embodiment, the optical disc recording / reproducing apparatus 1 performs the running OPC that controls the laser power during recording by the amount of reflected light from the optical disc 1 when the optical pickup 3 records on the optical disc 1.

  The processing operation of the fourth embodiment will be described below with reference to flowcharts showing the target setting processing operation shown in FIGS.

  The system controller 10 first performs OPC (step S31), measures the amount of reflected light at the laser power determined by the execution of this OPC (specifically, measures the ratio of the amount of reflected light to the amount of emitted light), of which The amount of reflected light on the circumferential side is stored in the EEPROM 11 (step S32).

  Next, the system controller 10 performs test writing on the outer peripheral side of the optical disc with the laser power determined by the OPC (step S33), measures the amount of reflected light, and stores the reflected light amount on the outer peripheral side in the EEPROM 11. (Step S34).

  Next, the system controller 10 calculates an approximate expression L of the reflected light amount from the difference between the inner peripheral side reflected light amount at the laser power determined by the OPC implementation and the outer peripheral side reflected light amount measured by the test writing (step S35). ). This approximate expression L is stored in the EEPROM 11.

Specifically, the amount of reflected light on the inner circumference side at the laser power determined by the OPC implementation is A1 (%), the amount of reflected light on the outer circumference side measured by the test writing is A2 (%), and the OPC implementation position on the inner circumference side of the optical disc. When the distance to the test writing position on the outer peripheral side is X, the approximate expression L is
L = (L2-L1) / X + L1
It becomes.

  When the approximate expression L is calculated in this way and stored in the EEPROM 11 and a write instruction is input from the middle of the disk (step S41), the system controller 10 uses the approximate expression L to execute the target of the running OPC. The amount of reflected light is calculated and set (step S42).

For example, when the writing position of the optical disc is a distance X1 from the OPC execution position Z1 on the inner peripheral side of the optical disc to the outer peripheral side, the reflected light amount L (X1) serving as a target at the start of writing is
L (X1) = ΔX (L2−L1) / X + L1
It becomes.

  This makes it possible to set a target in consideration of changes in reflectance characteristics and changes in asymmetry characteristics. The system controller 10 sets the reflected light amount L (X1) as a target and performs running OPC while writing data to the optical disc 1 in accordance with a write instruction (step S43).

  In the system controller 10, the above-described steps S <b> 41 to S <b> 43 are performed every time there is a write instruction from the middle of the disc to the same optical disc 1. That is, every time there is a writing instruction, the optimum amount of reflected light is set to the target each time according to the approximate expression L.

1 is a system configuration diagram of a DVD recorder that is an embodiment of a disc playback apparatus of the present invention. FIG. It is a flowchart which shows the processing operation which calculates | requires an approximate expression among the target setting processing operations of Example 1. FIG. It is a flowchart which shows the processing operation which implements running OPC using the calculated | required approximate expression among the target setting processing operations of Example 1. FIG. 3 is an explanatory diagram of an approximate expression according to Embodiment 1. FIG. 10 is a flowchart illustrating a target setting process operation according to the second embodiment. 10 is an explanatory diagram of an approximate expression according to Embodiment 3. FIG. It is a flowchart which shows the processing operation which calculates | requires an approximate expression among the target setting processing operations of Example 4. It is a flowchart which shows the processing operation which implements running OPC using the calculated | required approximate expression among the target setting processing operations of Example 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle motor 3 Pickup 4 Feed motor 5 RF amplifier 6 DRAM
7 Digital signal processing circuit 8 Laser driver 9 Servo processing circuit 10 System controller 11 EEPROM
12 D / A conversion circuit 13 Display panel 14 Receiver 18 Remote control 21 Display device

Claims (6)

In an optical disk recording / reproducing apparatus including a control unit that performs running OPC (Optimum Power Control) for controlling laser power during recording when recording on an optical disk by an optical pickup,
The control unit performs test writing on the outer peripheral side of the optical disc with the laser power determined by performing the OPC on the inner peripheral side of the optical disc, measures an asymmetry value, and asymmetry with the laser power determined by the OPC implementation. An approximate expression A of the asymmetry value is calculated from the difference between the value and the asymmetry value measured by the test writing, and the target asymmetry value at the writing position of the optical disc is set as needed according to the approximate expression A to execute the running OPC. In addition, the approximate expression A is as follows: the asymmetry value at the laser power determined by the OPC execution is A1, the asymmetry value measured by the test writing is A2, and the OPC execution position on the inner peripheral side of the optical disc If the distance to the test writing position is X,
A = (A2-A1) / X + A1
An optical disc recording / reproducing apparatus characterized by the above. In an optical disk recording / reproducing apparatus including a control unit that performs running OPC (Optimum Power Control) for controlling laser power during recording when recording on an optical disk by an optical pickup,
The control unit performs test writing on the outer peripheral side of the optical disc with the laser power determined by performing the OPC on the inner peripheral side of the optical disc, measures an asymmetry value, and asymmetry with the laser power determined by the OPC implementation. An approximate expression of the asymmetry value is calculated from the difference between the value and the asymmetry value measured by the test writing, and the running OPC is performed by setting a target asymmetry value at the writing position of the optical disc as needed according to the approximate expression. An optical disc recording / reproducing apparatus.   The control unit performs the test writing every time data is written to the optical disc to measure the asymmetry value, and the asymmetry value at the laser power determined by the OPC execution and the asymmetry value measured by the test writing. The optical disk recording / reproducing apparatus according to claim 2, wherein an approximate expression is calculated each time from the difference between the optical disk and the optical disk. The approximate expression A is that the asymmetry value at the laser power determined by the OPC execution is A1, the asymmetry value measured by the test writing is A2, and from the OPC execution position on the inner periphery side of the optical disk to the test write position on the outer periphery side. If the distance of X is X,
A = (A2-A1) / X + A1
The optical disc recording / reproducing apparatus according to claim 3, wherein In an optical disk recording / reproducing apparatus including a control unit that performs running OPC (Optimum Power Control) for controlling laser power during recording when recording on an optical disk by an optical pickup,
The controller performs test writing at a plurality of locations in the radial direction of the optical disk with laser power determined by performing OPC on the inner circumference side of the optical disk, measures asymmetry values, and determines the laser determined by performing the OPC. An approximate expression of the asymmetry value is calculated based on the asymmetry value at power and the respective asymmetry values measured in the test writing, and the target asymmetry value at the writing position of the optical disc is set as needed according to the approximate expression. An optical disc recording / reproducing apparatus that performs the running OPC. In an optical disc recording / reproducing apparatus including a control unit that performs a running OPC (Optimum Power Control) for controlling the laser power during recording by the amount of light reflected from the optical disc when recording on the optical disc by an optical pickup.
The control unit performs test writing on the outer peripheral side of the optical disc with the laser power determined by performing the OPC on the inner peripheral side of the optical disc, measures the amount of light reflected from the optical disc, and determines the laser power determined by the OPC implementation. An approximate expression of the reflected light quantity is calculated from the difference between the reflected light quantity at the test and the reflected light quantity measured in the test writing, and the target reflected light quantity at the writing position of the optical disc is set as needed according to the approximate expression, and the running OPC is performed. An optical disc recording / reproducing apparatus characterized in that