JP5093153B2 - Optical disc apparatus and optimum adjustment value setting method - Google Patents

Description

  The present invention relates to an optical disc apparatus and an optimum adjustment value setting method, and is suitable for application to an optical disc apparatus that performs calibration when recording information on an optical disc or reproducing information from an optical disc, for example.

  Conventionally, in an optical disc apparatus, information is recorded on an optical disc such as a CD (Compact Disc), a DVD (Digital Versatile Disc), and a Blu-ray Disc (registered trademark, hereinafter referred to as BD), and information is also recorded from the optical disc. What is read and reproduced is widely used.

  In general, an optical disc has variations in characteristics due to variations at the time of manufacture, an environment after manufacture, temperatures at the time of recording / reproduction, and the like. For this reason, the optical disk apparatus has variations in characteristics such as recording, reproduction, and servo with respect to the optical disk.

  This optical disc apparatus is configured to perform stable recording / reproduction and the like by previously setting optimum adjustment values for the entire optical disc apparatus. At this time, the optical disc apparatus needs to execute calibration that requires a relatively long time in order to set an optimum adjustment value.

  Calibration is a process for adjusting the recording, reproduction, servo, etc. and setting the optimum adjustment value so that the optical disk apparatus irradiates a laser beam in an optimal state at a desired position on the optical disk.

  One item of calibration is, for example, OPC (Optimum Power Control). OPC is a method of reading a recording mark after writing a test recording mark on a predetermined area of an optical disk while changing the output of the laser light, and reading the laser mark when the data recording quality is optimum. This is a process of setting an output adjustment value as an optimal adjustment value (see, for example, Patent Document 1).

  Furthermore, a multilayer recording type optical disc having a plurality of recording layers has variations in characteristics such as recording, reproduction, and servo for each recording layer. When setting an optimum adjustment value for such a multi-layer recording type optical disc, the optical disc apparatus needs to execute calibration for each recording layer of the optical disc, so that it takes time to set the optimum adjustment value compared to a single-layer optical disc. Cost.

JP 2006-318561 A

  By the way, in recent years, there is an optical disc apparatus that has a plurality of optical heads and increases the recording / reproducing rate for the optical disc.

  In such an optical disk apparatus, since calibration is performed for all recording layers of the optical disk for each optical head, it takes a very long time to set optimum adjustment values for all optical heads. .

  The present invention has been made in consideration of the above points, and in an optical disc apparatus having a plurality of optical heads for recording or reproducing information on an optical disc having a plurality of recording layers, all the recording layers of the optical disc in all the optical heads. An optical disc apparatus and an optimum adjustment value setting method that can set an optimum adjustment value for a short time are proposed.

  In order to solve such problems, in the optical disc apparatus of the present invention, a light source that emits a light beam, an objective lens that focuses the light beam on a target recording layer among three or more recording layers provided on the optical disc, Two or more optical heads each having a light receiving portion on which a light beam emitted from a light source and reflected by an optical disk is incident, and an adjustment for adjusting a light beam irradiated to a target recording layer based on a predetermined adjustment value , A calibration execution unit for obtaining an optimum adjustment value in the adjustment unit, and an optical head to perform calibration in parallel with the first recording layer of the optical disc to obtain an adjustment value, and two or more light beams Each head performs calibration in parallel with two or more different recording layers other than the first recording layer of the optical disc to obtain an adjustment value, From the relationship between the adjustment value of the first recording layer of the optical disk and the adjustment value of the other recording layer in the fixed optical head, and the adjustment value of the first recording layer of the optical disk in the other optical head, the other light An optimum adjustment value calculation unit for calculating adjustment values of other recording layers of the optical disc in the head is provided.

  Thereby, in the optical disc apparatus of the present invention, the number of calibrations for the recording layer of the optical disc in the optical head can be reduced.

  In the optimum adjustment value setting method of the present invention, a light source that emits a light beam, an objective lens that focuses the light beam on a target recording layer among three or more recording layers provided on the optical disc, and a light source Two or more optical heads each having a light receiving portion on which a light beam emitted and reflected by the optical disc is incident adjusts the light beam applied to the target recording layer with respect to the first recording layer of the optical disc. The first step of executing calibration for obtaining the optimum adjustment value in parallel and two or more optical heads in parallel with two or more different recording layers other than the first recording layer of the optical disc The second step of obtaining an adjustment value by executing calibration, and the relationship between the adjustment value of the first recording layer and the adjustment value of other recording layers of the optical disk in a predetermined optical head , From the adjustment value of the first recording layer of the optical disc in the other of the optical head, it was provided and a third step of calculating the adjustment value of the other recording layer of the optical disc in the other optical head.

  Thereby, in the optimum adjustment value setting method of the present invention, the number of calibrations for the recording layer of the optical disk in the optical head can be reduced.

  According to the present invention, the optical disc apparatus can reduce the number of calibrations for the recording layer of the optical disc in the optical head. Thus, the present invention records or reproduces information on an optical disc having a plurality of recording layers, and in an optical disc apparatus having a plurality of optical heads, the optimum adjustment values for all the recording layers of all the optical discs in all the optical heads are set in a short time. An optical disc device and an optimum adjustment value setting method can be realized.

1 is a schematic top perspective view showing a configuration of an optical disc device. 1 is a schematic block diagram showing a circuit configuration of an optical disc device. It is a basic diagram which shows the structure of an optical head unit. It is a basic diagram which shows the optimal adjustment value table | surface (1). It is a flowchart which shows the optimal adjustment value setting process sequence (1). It is a flowchart which shows the optimal adjustment value setting process procedure (2). It is a flowchart which shows the optimal adjustment value setting process sequence (3). It is a basic diagram which shows an optimal adjustment value table | surface (2). It is a basic diagram which shows an optimal adjustment value table | surface (3). It is a basic-line block diagram which shows the circuit structure (1) of the optical disk apparatus in other embodiment. It is a basic block diagram which shows the circuit structure (2) of the optical disk apparatus in other embodiment. It is a basic-line block diagram which shows the circuit structure (3) of the optical disk apparatus in other embodiment.

Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. Embodiment (Optical Disc Device, Optimal Adjustment Value Setting Method)
2. Other embodiments

<1. Embodiment>
[1-1. Configuration of optical disc apparatus]
As shown in FIG. 1, the optical disc apparatus 1 can record information and reproduce information from the optical disc 100 by irradiating the optical disc 100 with a light beam via the objective lens 6.

  The optical disc 100 is a multi-layer recording type and has four recording layers. As the optical disc 100 comes closer to the recording layer farthest from the objective lens 6, the recording layers L0 to L3 are arranged. Further, the optical disc 100 is provided with a PCA (Power Calibration Area) for writing a test recording mark in each recording layer when performing OPC.

  The optical disc apparatus 1 has a spindle motor 4M that rotationally drives the optical disc 100 via a turntable 4T. The optical disc apparatus 1 also has optical head units 2A and 2B that are moved in the radial direction of the optical disc 100 by feed motors 5M1 and 5M2 and lead screws 5S1 and 5S2.

  Two sets of independent optical heads 3A and 3B are mounted on the optical head unit 2A, and two sets of independent optical heads 3C and 3D are mounted on the optical head unit 2B. For this reason, the optical disk apparatus 1 is equipped with four sets of optical heads 3A, 3B, 3C and 3D.

  Furthermore, the optical disc apparatus 1 has an electronic circuit board 7 on which various electronic components are mounted. As shown in FIG. 2, the electronic circuit board 7 includes an overall control unit 11 that performs overall control of the optical disk apparatus 1 and performs various signal processing, control units 12A to 12D that control the optical heads 3A to 3D, and a spindle motor 4M. It functions as a spindle motor drive unit 13 or the like for driving the motor.

  The overall control unit 11 is configured to perform overall control of the optical disc apparatus 1 and includes a CPU (Central Processing Unit) (not shown) and a memory (not shown) used as a work memory of the CPU.

  The control units 12A to 12D perform control of the optical heads 3A to 3D, calibration, and the like while communicating with the host 16 outside the optical disc apparatus 1 via the overall control unit 11, respectively.

  The overall control unit 11 separates various optical head control data from the host 16 and information recorded on the optical disc 100, and distributes and supplies them to the control units 12A to 12D. Further, when the reproduction information from the optical disc 100 is supplied from each of the control units 12A to 12D, the overall control unit 11 multiplexes the reproduction information and transmits it to the host 16.

  In this way, the overall control unit 11 multiplexes reproduction information and the like from the control units 12A to 12D, together with the separation of various data into the control units 12A to 12D. For this reason, the host 16 can handle the optical disk apparatus 1 on which the four sets of optical heads 3A to 3D are mounted in the same manner as the optical disk apparatus on which a set of optical heads are mounted.

  Since all of the optical heads 3A to 3D are configured in the same manner, the optical head 3C will be described below as an example. The control unit 12C rotates the spindle motor 4M via the spindle motor driving unit 13 to rotate the optical disc 100 mounted on the turntable 4T at a desired speed.

  Furthermore, the control unit 12C drives and controls an actuator (not shown) of the optical head 3C via the drive control unit 18C. As a result, the control unit 12C moves the objective lens 6C in the focus direction, which is a direction in which the objective lens 6C approaches or separates from the optical disc 100, and finely moves the objective lens 6C in the tracking direction orthogonal to the track direction of the optical disc 100. Make adjustments.

  For example, when recording information on the optical disc 100, the control unit 12C performs a predetermined encoding process, a modulation process, and the like on the information, thereby generating a laser control signal CL3 corresponding to the information, and the laser control signal CL3. Is supplied to the optical head 3C.

  The optical head 3C emits an information recording light beam L1 having a relatively high light intensity based on the laser control signal CL3 supplied from the controller 12C. Subsequently, the optical head 3C irradiates the optical disk 100 with the light beam L1 via the objective lens 6C whose position has been adjusted. Thereby, the optical head 3 </ b> C can record information on the optical disc 100.

  When the control unit 12C reproduces information from the optical disc 100, the control unit 12C supplies a laser control signal CL3 from the control unit 12C to the optical head 3C so that information with relatively low light intensity from the optical head 3C to the optical disc 100 is obtained. A reproduction light beam L1 is irradiated. At the same time, the optical head 3C detects the reflected light beam L2 formed by reflecting the light beam L1, generates a detection signal U3 corresponding to the detection result, and supplies the detection signal U3 to the control unit 12C.

  The control unit 12C generates a reproduction RF signal based on the detection signal U3, and performs predetermined demodulation processing, decoding processing, and the like on the detection signal U3, thereby reproducing information recorded on the optical disc 100. Yes.

  The control unit 12C generates a focus error signal SFE and a tracking error signal STE based on the detection signal U3, and supplies them to the drive control unit 18C.

  Thereby, the control unit 12C controls the focus servo for controlling the objective lens 6C so as to focus the laser beam L1 on the desired recording layer, and the objective lens 6C so that the laser beam L1 traces a desired track on the optical disc 100. The tracking servo that controls is performed.

  In this way, the optical head 3C can record or reproduce information by adjusting the position of the objective lens 6C and the like and then irradiating the optical disk 100 with the light beam L1 through the objective lens 6C. Has been made.

[1-2. Configuration of optical head]
As shown in FIG. 3, the optical head 3C is mounted on the optical head unit 2B. In the optical head unit 2B, an optical head 3D is arranged symmetrically with the optical head 3C with the virtual straight line VL as a symmetry line. Incidentally, the virtual straight line VL intersects with the rotation center axis of the optical disc 100.

  Based on the control of the control unit 12C (FIG. 2), the optical head 3C emits an outgoing light beam L1 made of divergent light from the laser diode 31C, and converts the outgoing light beam L1 from divergent light to parallel light by the collimator lens 32C. Then, it is made incident on the attenuating liquid crystal 33C.

  The attenuation liquid crystal 33C suppresses the quantization noise of the outgoing light beam L1 by attenuating the intensity of the outgoing light beam L1, and enters the polarization beam splitter 34C.

  The polarization plane 34C1 of the polarization beam splitter 34C transmits almost all of the light amount in the outgoing light beam L1, and enters the polarization plane 34C2. At the same time, the polarization plane 34C1 reflects a part of the light amount in the emitted light beam L1 at a predetermined ratio and makes it incident on the photodetector 35C for confirming the attenuation liquid crystal operation.

  The controller 12C monitors the operating state of the attenuating liquid crystal 33C by detecting the amount of light incident on the attenuating liquid crystal operation checking photodetector 35C. Thus, the control unit 12C can attenuate the outgoing light beam L1 by a desired intensity.

  The polarization plane 34C2 of the polarization beam splitter 34C transmits almost all of the amount of light in the outgoing light beam L1 that has passed through the polarization plane 34C1, corrects aberrations by the aberration correction liquid crystal 36C, and enters the rising mirror 37C. At the same time, the polarization plane 34C2 reflects a part of the light amount in the emitted light beam L1 at a predetermined ratio and makes it incident on the front photodetector 39C through the coupling lens 38C.

  The front photodetector 39C detects the amount of incident light, generates an APC (Automatic Power Control) detection signal AS3 having a current value corresponding to the amount of light, and supplies it to the controller 12C.

  The control unit 12C adjusts the light intensity of the light beam L1 emitted from the laser diode 31C by controlling the laser control signal CL3 supplied to the laser diode 31 based on the APC detection signal AS3.

  In this way, the control unit 12C adjusts the light intensity of the outgoing light beam L1 emitted from the laser diode 31C to a desired intensity by detecting the amount of light incident on the front photodetector 39C and performing feedback control. Yes.

  Subsequently, the optical head 3C sequentially passes through the rising mirror 37C, the quarter-wave plate 40C, and the expander lens 41C, and outputs the emitted light beam L1 to the desired track of the recording layer in the optical disc 100 (FIG. 1) by the objective lens 6C. Focus on.

  The expander lens 41C includes a first expander lens 41C1 that is movable in a direction along the optical axis of the light beam L1 by an actuator (not shown), and a fixed second expander lens 41C2.

  The first expander lens 41C1 moves a predetermined distance based on the control of the drive control unit 18C. As a result, the expander lens 41C preliminarily gives the light beam L1 a spherical aberration that is opposite to the spherical aberration that occurs when the light beam L1 is condensed and reaches the recording layer of the optical disc 100, thereby correcting the spherical aberration. It is made to do.

  The objective lens 6C is moved in the focus direction and the tracking direction by an actuator (not shown) based on the control from the drive control unit 18C, and the tilt is changed, that is, tilted in the radial direction.

  The optical head 3C converts the reflected light beam L2 obtained by reflecting the emitted light beam L1 on the recording layer of the optical disc 100 (FIG. 1) into an objective lens 6C, an expander lens 41C, a quarter wavelength plate 40C, a rising mirror 37C, and The light is incident on the polarization beam splitter 34C sequentially through the aberration correction liquid crystal 36C.

  The polarization beam splitter 34C reflects the reflected light beam L2 on the polarization plane 34C2, diffracts it by the hologram plate 42C, condenses it through the multi-lens 43C, and enters the photodetector 44C.

  The photodetector 44C detects the reflected light beam L2, generates a detection signal U3 corresponding to the detection result, and supplies the detection signal U3 to the control unit 12C.

[1-3. Optimal adjustment value setting of optical head]
By the way, in order to record information on the optical disc 100, the control unit 12C needs to irradiate the light beam L1 with an appropriate laser power. Therefore, the optical head 3C performs test writing on the PCA provided on the optical disc 100 as one item of calibration, and performs OPC to determine the laser power at which information is properly recorded.

  The control unit 12C records test data by changing the emitted light intensity of the light beam L1 variously in each PCA of the recording layers L0 to L3 provided on the optical disc 100. Then, the control unit 12C sets the value of the APC detection signal AS3 when the test data is reproduced and the signal quality of the reproduced RF signal becomes the best as the reference current value for the optical disc 100.

  Then, the control unit 12C stores the value of the optimum detection signal AS3 in the storage unit 19 via the calculation unit 17 as an optimal adjustment value of OPC which is one item of calibration.

  As described above, the optical disc apparatus 1 performs focus servo and tracking servo when recording and reproducing on the optical disc 100.

  Prior to recording / reproducing on / from the optical disc 100, the control unit 12C moves the objective lens 6C by a predetermined distance in the focus direction while moving the push-pull signal included in the detection signal U3, the jitter amount included in the reproduced RF signal, and the like. Is used to determine the optimum focus bias value.

  Then, the control unit 12C stores the optimal focus bias value in the storage unit 19 via the calculation unit 17 as an optimum adjustment value of the focus bias that is one item of calibration.

  The controller 12C adds the focus bias value to the focus error signal SFE, and performs focus servo based on the focus error signal to which the focus bias value is added.

  The control unit 12C drives an actuator (not shown) by the drive control unit 18C, and changes the position of the first expander lens 41C1 in the focus direction while detecting the jitter amount and the like included in the reproduction RF signal. Thereby, the control unit 12C obtains the optimum moving distance of the first expander lens 41C1 for correcting the spherical aberration generated in the light beam L1.

  Then, the control unit 12C causes the storage unit 19 to store the optimal moving distance as an optimal adjustment value for spherical aberration correction, which is one item of calibration.

  Furthermore, the controller 12C tilts the objective lens 6C in the radial tilt direction while performing predetermined signal processing based on the detection signal U3 and the like, thereby obtaining an optimal radial tilt angle that compensates for the tilt of the optical disc 100 in the radial direction. Ask.

  Then, the control unit 12C stores the optimal radial tilt angle in the storage unit 19 via the calculation unit 17 as an optimal adjustment value for radial tilt correction which is one item of calibration.

  Further, the control unit 12C, based on the detection signal U3, a lens shift signal (of the objective lens 6C) obtained by multiplying a push-pull signal (relative displacement between the focal point of the light beam L1 and the desired track) by a desired coefficient Kt. Subtract the displacement in the tracking direction. Thereby, the control unit 12C obtains the tracking error signal STE.

  At that time, the control unit 12C obtains the optimum value of the coefficient Kt by moving the objective lens 6C by a predetermined distance in the tracking direction so that the AC component included in the tracking error signal STE is minimized.

  Then, the control unit 12C stores the optimal coefficient Kt in the storage unit 19 via the calculation unit 17 as an optimal adjustment value for tracking error offset cancellation which is one item of calibration.

  Prior to recording and reproduction, the controller 12C obtains various optimum adjustment values as described above for all the recording layers L0 to L3 of the optical disc 100 for the optical head 3C.

  Although the optical head 3C has been described above, the optical heads 3A, 3B, and 3D perform substantially the same calibration as that of the optical head 3C on all the recording layers L0 to L3 of the optical disc 100. As a result, the optical disk apparatus 1 can record and reproduce information in an optimum state with respect to the optical disk 100.

  The storage unit 19 stores an optimum adjustment value table TBL1 shown in FIG. The optical disc apparatus 1 stores optimum adjustment values for combinations of all the optical heads 3A to 3D and all the recording layers L0 to L3 of the optical disc 100 in the optimum adjustment value table TBL1. Hereinafter, a combination of the optical heads 3A to 3D and the recording layers L0 to L3 of the optical disc 100 in the optimum adjustment value table TBL1 is also referred to as a setting item Q.

[1-4. Optimal adjustment value setting method]
By the way, the optical disk apparatus 1 executes calibration for the 16 combinations that are the products of the four sets of optical heads 3A to 3D and the four recording layers L0 to L3 of the optical disk 100, so that the optimum adjustment value is obtained. It is necessary to ask.

  Here, since the optical heads 3A and 3B are configured in the same manner, the characteristics of both are similar as a whole, and a slight individual difference occurs. Further, the recording layers L0 and L1 of the optical disc 100 are configured uniformly.

  Therefore, the difference in the optimum adjustment value between the recording layers L0 and L1 of the optical disk 100 in the optical head 3B is considered to have some relationship with the difference between the recording layers L0 and L1 in the optical head 100 in the optical head 3A.

  In such a case, for example, by using the relationship between the optimum adjustment values of the recording layers L0 and L1 of the optical disk 100 in the optical head 3B, the optimum adjustment value of the recording layer L1 is obtained from the optimum adjustment value of the recording layer L0 in the optical head 3A. Can be obtained by calculation.

  Therefore, the optical disc apparatus 1 performs calibration for some of the setting items Q, but calculates the optimum setting value by performing calculation for the remaining setting items Q without performing calibration. Yes.

  In the optimum adjustment value table TBL1, the setting items Q for executing the calibration and obtaining the optimum adjustment values are the setting items QA0, QB0, QC0, QD0, QB1, QC2 and QD3. In the optimum adjustment value table TBL1, the setting item Q for calculating the optimum adjustment value only by calculation without performing calibration is the setting items QA1, QA2, QA3, QB2, QB3, QC1, QC3, QD1, and QD2. It has become.

  The optimum adjustment value setting processing procedure when the optical disc apparatus 1 sets the optimum adjustment value of OPC, which is one item of calibration, for all the recording layers of the optical disc 100 in all the optical heads will be described below with reference to FIGS. 6 and the flowchart of FIG.

  When the optical disc 100 is loaded in the optical disc apparatus 1, the control units 12A to 12D of the optical disc apparatus 1 simultaneously start the optimum adjustment value setting processing procedures RT1 to RT4 under the control of the overall control unit 11, respectively. Then, the control units 12A to 12D move to steps SP1, SP21, SP31 and SP41, respectively, and enter the timing T1 of the calibration execution stage D1. In the calibration execution stage D1, the control units 12A to 12D execute calibration while synchronizing the timing under the control of the overall control unit 11.

  The optimum adjustment value setting processing procedure when the optical disc apparatus 1 sets the optimum adjustment value of OPC, which is one item of calibration, for all the recording layers of the optical disc 100 in all the optical heads will be described below with reference to FIGS. 6 and the flowchart of FIG.

  In step SP1, the control unit 12A controls the optical head 3A and performs OPC on the recording layer L0 of the optical disc 100. Then, the control unit 12A supplies the detection signal AS1 obtained by OPC to the calculation unit 17 as the OPC optimum adjustment value A, and also sets the setting item QA0 (optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17). 8), and the process proceeds to step SP2.

  In step SP21, the control unit 12B controls the optical head 3B and performs OPC on the recording layer L0 of the optical disc 100 simultaneously with step SP1. Then, the control unit 12B supplies the optimum adjustment value B to the calculation unit 17, and stores the optimum adjustment value B in the setting item QB0 of the optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17, and proceeds to step SP22.

  As described above, since the control units 12A to 12D control the optical heads 3A to 3D separately, the control units 12A to 12D can execute calibration simultaneously in parallel with each other.

  In step SP31, the control unit 12C controls the optical head 3C and performs OPC on the recording layer L0 of the optical disc 100 simultaneously with steps SP1 and SP21. Then, the control unit 12C supplies the optimum adjustment value C to the calculation unit 17, stores the setting value QC0 in the optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17, and proceeds to step SP32.

  In step SP41, the control unit 12D controls the optical head 3D and performs OPC on the recording layer L0 of the optical disc 100 simultaneously with steps SP1, SP21, and SP31. Then, the control unit 12D supplies the optimum adjustment value D to the calculation unit 17, and stores the optimum adjustment value D in the setting item QD0 of the optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17, and proceeds to step SP42.

  Through the processing in steps SP1, SP21, SP31 and SP41, the optimum adjustment value table TBL1 stores the optimum adjustment values for the recording layer L0 of the optical disc 100 in all the optical heads as in the setting items QA0, QB0, QC0 and QD0. Is done. Moreover, the calculating part 17 acquires optimal adjustment value A, B, C, and D from control part 12A, 12B, 12C, and 12D.

  At step SP2 at timing T2, the control unit 12A waits without executing calibration, and proceeds to step SP3 (FIG. 6).

  In step SP22, the control unit 12B performs OPC on the recording layer L1 of the optical disc 100. Then, the control unit 12B supplies the optimum adjustment value E to the calculation unit 17, and stores the optimum adjustment value E in the setting item QB1 of the optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17, and proceeds to step SP23.

  In step SP32, the control unit 12C performs OPC on the recording layer L2 of the optical disc 100 simultaneously with step SP22. Then, the control unit 12C supplies the optimum adjustment value F to the calculation unit 17, stores the setting value QC2 in the optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17, and proceeds to step SP33.

  In step SP42, the control unit 12D performs OPC on the recording layer L3 of the optical disc 100 simultaneously with steps SP22 and SP32. Then, the control unit 12D supplies the optimum adjustment value G to the calculation unit 17, and stores the optimum adjustment value G in the setting item QD3 of the optimum adjustment value table TBL1 in the storage unit 19 via the calculation unit 17, and proceeds to step SP43.

  As a result of the processing in steps SP22, SP32 and SP42, the optimum adjustment value table TBL1 stores optimum adjustment values E, F and G in the setting items QB1, QC2 and QD3, respectively. Moreover, the calculating part 17 acquires the optimal adjustment values E, F, and G from the control parts 12B, 12C, and 12D, respectively.

  As described above, in the optical disc apparatus 1, all the optical heads execute OPC in the recording layer L0 of the optical disc 100, but in the recording layers L1, L2, and L3, OPC is performed only in the optical heads 3B, 3C, and 3D, respectively. Running.

  In the above processing (calibration execution stage D1), the control units 12A to 12D have obtained the optimal adjustment values by executing OPC. However, in the following calculation stage D2, the control units 12A to 12D do not execute OPC. The optimum adjustment value is obtained only by calculation by the calculation unit 17. In the calculation stage D2, the calculation unit 17 performs calculation under the control of the overall control unit 11.

  In step SP3, the calculation unit 17 enters the calculation stage D2, and based on the optimal adjustment value A supplied from the control unit 12A and the optimal adjustment values B and E supplied from the control unit 12B, the calculation unit A + (E−B) An operation is performed to calculate the optimum adjustment value for the recording layer L1 in the optical head 3A.

  Here, the correspondence between the OPC optimum adjustment value B for the recording layer L0 and the OPC optimum adjustment value E for the recording layer L1 in the optical head 3B can be expressed by a difference (E−B). The correspondence relationship is similarly expressed for the optimum adjustment values of the recording layer L0 and the recording layer L1 in the optical heads 3A, 3C, and 3D other than the optical head 3B.

  Further, in the optical disc apparatus 1 according to the present invention, the correspondence relationship of the optimum adjustment value between the predetermined recording layer of the optical disc and the other recording layer in the predetermined optical head is determined by using the predetermined recording layer in the other optical head, The present invention can also be applied to optimum adjustment values with other recording layers.

  And the calculating part 17 memorize | stores the optimal adjustment value obtained by the said calculation in the setting item QA1 of the optimal adjustment value table TBL1 in the memory | storage part 19, and moves to step SP4.

  In step SP4, the calculation unit 17 calculates A + (FC) based on the optimum adjustment values A, C, and F, and calculates the optimum adjustment value for the recording layer L2 in the optical head 3A. And the calculating part 17 memorize | stores the said optimal adjustment value in the setting item QA2 of the optimal adjustment value table TBL1 in the memory | storage part 19, and moves to step SP5.

  In step SP5, the calculation unit 17 calculates A + (GD) based on the optimum adjustment values A, D, and G, and calculates the optimum adjustment value for the recording layer L3 in the optical head 3A. Then, the calculation unit 17 stores the optimum adjustment value in the setting item QA3 of the optimum adjustment value table TBL1 in the storage unit 19, moves to step SP6, and ends the optimum adjustment value setting process RT1.

  As a result, the optical disc apparatus 1 can store the optimum adjustment values for all the recording layers of the optical disc 100 in the optical head 3A in the storage unit 19.

  In step SP23, when the calculation in step SP5 is completed, the calculation unit 17 calculates B + (F−C) based on the optimum adjustment values B, C, and F, and obtains the optimum adjustment value for the recording layer L2 in the optical head 3B. calculate. And the calculating part 17 memorize | stores the said optimal adjustment value in the setting item QB2 of the optimal adjustment value table | surface TBL1 in the memory | storage part 19, and moves to step SP24.

  In step SP24, the calculation unit 17 calculates B + (GD) based on the optimum adjustment values B, D, and G, and calculates the optimum adjustment value for the recording layer L3 in the optical head 3B. Then, the calculation unit 17 stores the optimum adjustment value in the setting item QB3 of the optimum adjustment value table TBL1 in the storage unit 19, moves to step SP25, and ends the optimum adjustment value setting process RT2.

  Thereby, the optical disc apparatus 1 can store the optimum adjustment values for all the recording layers of the optical disc 100 in the optical head 3B in the storage unit 19.

  In step SP33 (FIG. 7), when the calculation in step SP24 is completed, the calculation unit 17 calculates C + (E−B) based on the optimum adjustment values B, C, and E, and calculates the recording layer L1 in the optical head 3C. The optimum adjustment value is calculated. And the calculating part 17 memorize | stores the said optimal adjustment value in the setting item QC1 of the optimal adjustment value table TBL1 in the memory | storage part 19, and moves to step SP34.

  In step SP34, the calculation unit 17 calculates C + (GD) based on the optimum adjustment values C, D, and G, and calculates the optimum adjustment value for the recording layer L3 in the optical head 3C. Then, the calculation unit 17 stores the optimum adjustment value in the setting item QC3 of the optimum adjustment value table TBL1 in the storage unit 19, moves to step SP35, and ends the optimum adjustment value setting process RT3.

  As a result, the optical disc apparatus 1 can store the optimum adjustment values for all the recording layers of the optical disc 100 in the optical head 3C in the storage unit 19.

  In step SP43, when the calculation in step SP34 ends, the calculation unit 17 calculates D + (EB) based on the optimum adjustment values B, D, and E, and obtains the optimum adjustment value for the recording layer L1 in the optical head 3D. calculate. And the calculating part 17 memorize | stores the said optimal adjustment value in the setting item QD1 of the optimal adjustment value table | surface TBL1 in the memory | storage part 19, and moves to step SP44.

  In step SP44, the calculation unit 17 calculates D + (FC) based on the optimum adjustment values B, C, and F, and calculates the optimum adjustment value for the recording layer L2 in the optical head 3D. Then, the calculation unit 17 stores the optimum adjustment value in the setting item QD2 of the optimum adjustment value table TBL1 in the storage unit 19, moves to step SP45, and ends the optimum adjustment value setting process RT4.

  As a result, the optical disc apparatus 1 can obtain the optimum adjustment values for all the recording layers of the optical disc 100 in the optical head 3D. As described above, the optical disc apparatus 1 can obtain optimum adjustment values for all the recording layers of the optical disc 100 in all the optical heads 3A to 3D.

  Thereafter, the control units 12 </ b> A to 12 </ b> D refer to the optimum adjustment value table TBL <b> 1 and set the optimum adjustment value of OPC to the PCAs provided in all the recording layers of the optical disc 100.

  The optimal adjustment value of OPC as one item of calibration has been described above, but the above-described optimal adjustment value setting process can also be applied to the setting of optimal adjustment values for spherical aberration correction, radial tilt, and tracking error offset.

  However, in the case of the optimum adjustment value of the tracking error offset, the optimum adjustment value between different recording layers in the same optical head is different from the other calibration items described above in that there is a ratio relationship instead of a difference.

  That is, the correspondence between the optimum adjustment value B of the tracking error offset for the recording layer L0 and the optimum adjustment value E of the tracking error offset for the recording layer L1 in the optical head 3B is expressed by the ratio (E / B). The correspondence relationship is similarly expressed for the optimum adjustment values of the recording layers L0 and L1 in the optical heads 3A, 3C, and 3D other than the optical head 3B.

  In this case, the optical disc apparatus 1 executes calibration for the setting items QA0, QB0, QC0, QD0, QB1, QC2, and QD3 in the optimum adjustment value table TBL2 shown in FIG. Further, the optical disc apparatus 1 performs operations shown in the setting items QA1, QA2, QA3, QB2, QB3, QC1, QC3, QD1, and QD2 in the optimum adjustment value table TBL2 for the remaining setting items Q. Thereby, the optical disc apparatus 1 can obtain the optimum adjustment values for all the recording layers L0 to L3 of the optical disc 100 in all the optical heads 3A to 3D.

[1-5. Operation and effect]
In the above configuration, the optical disc apparatus 1 simultaneously executes calibration for the recording layer L0 of the optical disc 100 in all the optical heads 3A to 3D.

  Thereby, the optical disc apparatus 1 can complete the calibration with respect to the same recording layer of the optical disc 100 in all the optical heads 3A to 3D in a short time.

  Subsequently, the optical disc apparatus 1 simultaneously performs calibration on the recording layer L1 in the optical head 3B, on the recording layer L2 in the optical head 3C, and further on the recording layer L3 in the optical head 3D.

  As described above, the optical disk apparatus 1 is configured so that each optical head simultaneously executes calibration on a recording layer different from the other optical heads, and the optical disk apparatus 1 can use the optimum adjustment value for subsequent calculations. Has been made to ask for.

  As a result, the optical disc apparatus 1 can complete calibration for different recording layers of the optical disc 100 in a plurality of optical heads in a short time.

  Subsequently, the optical disc apparatus 1 supplies the optimum adjustment value obtained by the execution of the calibration to the calculation unit 17.

  As described above, the optical disk apparatus 1 uses the arithmetic unit 17 to share the optimal adjustment values obtained by the control units 12A to 12D performing the calibration. Thereby, the calculating part 17 can use the optimal adjustment value calculated | required by control part 12A-12D for calculation.

  Subsequently, based on those optimum adjustment values, the calculation unit 17 calculates the optimum adjustment values for the combinations in which the calibration is not performed among the combinations of the optical head and the recording layer in the optimum adjustment value table TBL1. .

  Here, when the calibration is executed for all the setting items Q, the optical disc apparatus 1 is the product of four sets of the optical heads 3A to 3D and the four recording layers L0 to L3 of the optical disc. There was a need to perform calibration.

  On the other hand, in the optimum adjustment value setting method according to the present invention, the optical disc apparatus 1 performs calibration only for the setting items QA0, QB0, QC0, QD0, QB1, QC2, and QD3 in the optimum adjustment value table TBL1.

  As described above, since the optical heads 3A to 3D of the optical disc apparatus 1 are similarly configured, the characteristics of the optical heads 3A to 3D are similar as a whole. In addition, the recording layers L0 to L3 of the optical disc 100 are configured uniformly. For this reason, in the optical disc apparatus 1, from the optimum adjustment value of the predetermined recording layer in the other optical head, the correspondence relationship of the optimum adjustment value between the predetermined recording layer and the other recording layer in the predetermined optical head is used. The optimum adjustment value of the other recording layer can be obtained by calculation.

  For this reason, in the optical disc apparatus 1, the execution of calibration requiring a long time is reduced to seven times.

  Even if the optical disc apparatus 1 simultaneously executes calibration of all the optical heads for a predetermined recording layer, the optical disc 100 has four recording layers. Therefore, at the calibration execution stage D1, timings T1 to T2 are obtained. It took twice as long as (Fig. 5).

  On the other hand, in the optimum adjustment value setting method according to the present invention, the optical disc apparatus 1 performs calibration only for the setting items QA0, QB0, QC0, QD0, QB1, QC2, and QD3 in the optimum adjustment value table TBL1.

  For this reason, as shown in the calibration execution stage D1, the optical disc apparatus 1 only takes time T1 to T2 to execute calibration.

  The optical disc apparatus 1 performs only the calculation process in the calculation stage D2. For this reason, the optical disc apparatus 1 can complete the calculation stage D2 in a very short time compared to the calibration execution stage D1 for executing calibration.

  For this reason, the optical disc apparatus 1 requires time to set the optimum adjustment value for all the recording layers of the optical disc in all the optical heads, compared to the case where the calibration is executed for all combinations of the optical head and the recording layer of the optical disc. Can be shortened to almost half.

  In the above configuration, the optical disc apparatus 1 simultaneously executes calibration for the recording layer L0 of the optical disc 100 in all the optical heads. In addition, the optical disc apparatus 1 simultaneously performs calibration on the recording layers L1, L2, and L3 of the optical disc 100 using only the optical heads 3B, 3C, and 3D, respectively. Furthermore, the optical disc apparatus 1 supplies the optimum adjustment value obtained by the execution of the calibration to the calculation unit 17. The calculation unit 17 determines, based on the correspondence relationship between the optimum adjustment values for the two recording layers of the optical disk in the predetermined optical head, for the combination of the optical head and the recording layer that have not been calibrated in the optimum adjustment value table TBL1. The optimum adjustment value is calculated. As a result, the optical disc apparatus 1 can reduce the number of calibrations for the recording layer of the optical disc in the optical head.

<2. Other embodiments>
In the embodiment described above, the optical disk apparatus 1 has been described as performing calibration prior to recording and reproduction when the optical disk 100 is loaded.

  However, the present invention is not limited to this, and the optical disc apparatus 1 may perform all or some of the calibration items described above even during recording and reproduction.

  Even in this case, the optical disc apparatus 1 can reduce the number of times of calibration for obtaining the optimum adjustment value for all the recording layers of the optical disc in all the optical heads.

  In the above-described embodiment, the optical disc apparatus 1 executes the calibration for the recording layer L0, and then the optical head 3B for the recording layer L1, the optical head 3C for the recording layer L2, and the optical head. The case where calibration is simultaneously performed on the recording layer L3 in 3D has been described.

  However, the present invention is not limited to this, and the optical disc apparatus 1 does not execute the calibration for the recording layer L3 in the optical head 3D simultaneously with the calibration that the optical heads 3A and 3B respectively execute for the recording layers L1 and L2. May be.

  In this case, the optical disc apparatus 1 may perform calibration on different recording layers in parallel in at least two or more sets of optical heads after performing calibration on the recording layer L0.

  As a result, the optical disk apparatus 1 can obtain the optimum adjustment value used in the subsequent calculation performed by the optical disk apparatus 1 in a short time compared with the case where calibration is performed on different recording layers by the same optical head. .

  In this case, the optimum adjustment value can be obtained in a shorter time as the calibration is simultaneously performed on different recording layers by more optical heads.

  Incidentally, if the optical disc 100 has five or more recording layers, the optical disc apparatus 1 continuously executes calibration for different recording layers in parallel in two or more sets of optical heads.

  In this case, the optical disc apparatus 1 performs calibration with any one of the optical heads in all the recording layers other than the recording layer L0, and obtains an optimum adjustment value. Thereby, the optical disc apparatus 1 can obtain the optimum adjustment value of the combination of the remaining optical head and the recording layer that has not been calibrated by calculation based on the optimum adjustment value.

  Further, in the above-described embodiment, the case where the optical disc apparatus 1 has four sets of optical heads and the optical disc 100 has four recording layers has been described.

  However, the present invention is not limited to this, and the optical disc apparatus 1 may have an arbitrary number of optical heads, and the optical disc 100 may have an arbitrary number of recording layers.

  In this case, the present invention is substantially effective when the optical disc apparatus has two or more sets of optical heads and the optical disc has three or more recording layers. Furthermore, the more the optical head 1 has more optical heads and the more the optical disc 100 has more recording layers, the more remarkable the effects of the present invention.

  Furthermore, in the above-described embodiment, the optical disc apparatus 1 includes the overall control unit 11, the control units 12A to 12D, the calculation unit 17, and the storage unit 19 as shown in FIG. Said.

  However, the present invention is not limited to this, and the optical disc apparatus may be configured as the optical disc apparatuses 201, 301, and 401 shown in FIGS. 10, 11, and 12, respectively.

  Compared to the optical disc apparatus 1, the optical disc apparatus 201 has storage units 19A to 19D provided in the optical heads 3A to 3D, respectively, and the optical heads 3A to 3D read the optimum adjustment values from the respective storage units 19A to 19D. ing.

  Also, the optical disk device 301 is omitted from the optical disk device 201 in that the storage units 19B and 19C are omitted, the storage unit 19A is shared by the optical heads 3A and 3B, and the storage unit 19D is shared by the optical heads 3C and 3D. ing.

  Further, in the optical disc device 401, the control units 12A to 12D are connected to the optical heads 3A to 3D via the arithmetic unit 17, respectively, as compared with the optical disc device 1.

  The optical disk apparatus may have various configurations as described above. In short, the control units 12A to 12D provided in the optical heads 3A to 3D are connected to the calculation unit 17, and the control units 12A to 12D are connected to each other. What is necessary is just to be able to acquire the data which the calculation part 17 has.

  Further, in the above-described embodiment, the case has been described in which optimum adjustment values for OPC, spherical aberration correction, focus bias, radial tilt, and tracking error offset cancellation are obtained as calibration items.

  However, the present invention is not limited to this. For example, only OPC may be performed, and it is not always necessary to perform all the items of the calibration described above.

  Further, the present invention may be applied to other calibration items other than the calibration items described above. In this case, any optical disk device or optical disk may be used as long as the corresponding relationship of the optimum adjustment value between a predetermined recording layer of the optical disk and another recording layer in the predetermined optical head can be applied to other optical heads.

  Further, in the above-described embodiment, as shown in the optimum adjustment value table TBL1 or TBL2, the correspondence relationship between the optimum adjustment value of the predetermined recording layer of the optical disc and the other recording layer in the predetermined optical head is the difference or The case of ratio is described.

  However, the present invention is not limited to this, and the correspondence relationship between the optimum adjustment values of the predetermined recording layer of the optical disk and other recording layers in the predetermined optical head may change exponentially, for example. In this case, the optimal adjustment value may be converted into a logarithm, and the calculation may be performed by converting the optimal adjustment value into an area that can be handled by a difference or a ratio.

  Furthermore, in the above-described embodiment, the case where the optimum adjustment value table TBL1 or TBL2 is stored in the storage unit 19 has been described. However, the present invention is not limited to this, and the optimum adjustment value table TBL1 or TBL2 may be stored in the calculation unit 17.

  Further, in the above-described embodiment, the laser diode 31 as the light source, the objective lens 6 as the objective lens, the photodetector 44 as the light receiving unit, the control unit 12 as the adjustment unit and the calibration execution unit, and the optimal adjustment The case where the optical disk device 1 as the optical disk device is configured by the control unit 12 and the calculation unit 17 as the value calculation unit has been described.

  However, the present invention is not limited to this, and an optical disc apparatus is configured by a light source having various other circuit configurations, an objective lens, a light receiving unit, an adjustment unit, a calibration execution unit, and an optimum adjustment value calculation unit. May be.

  INDUSTRIAL APPLICABILITY The present invention can be used in an optical disc apparatus or the like having a plurality of optical heads by recording or reproducing information with respect to an optical disc having a plurality of recording layers.

  1, 201, 301, 401 ... Optical disk device, 2A, 2B ... Optical head unit, 3A, 3B, 3C, 3D ... Optical head, 4M ... Spindle motor, 4T ... Turntable, 5M1, 5M2 ... Feed motor, 5S1, 5S2 ... lead screw, 6A, 6B, 6C, 6D ... objective lens, 7 ... electronic circuit board, 11 ... general control unit, 12 ... control unit, 13 ... spindle motor drive unit , 16 ... host, 17 ... computing unit, 18 ... drive control unit, 19 ... storage unit, 31 ... laser diode, 32 ... collimator lens, 33 ... attenuation liquid crystal, 34 ... polarization beam splitter, 35 …… Photodetector for attenuator liquid crystal operation check, 36 …… Aberration correction liquid crystal, 37 …… Rise mirror, 38 …… Coupling lens, 39 …… F Cement photodetector, 40 ...... 1/4-wave plate, 41 ...... expander lens, 42 ...... hologram plate, 43 ...... multi-lens, 44 ...... photodetector.

Claims (5)

A light source that emits a light beam;
An objective lens for condensing the light beam on a target recording layer among three or more recording layers provided on an optical disc;
A light receiving unit on which the light beam emitted from the light source and reflected by the optical disc is incident;
Two or more optical heads each having
An adjusting unit that adjusts the light beam applied to the target recording layer based on a predetermined adjustment value;
A calibration execution unit for obtaining an optimal adjustment value in the adjustment unit;
The respective optical heads perform calibration in parallel with the first recording layer of the optical disc to obtain an adjustment value, and two or more optical heads each other than the first recording layer of the optical disc. Calibration is performed in parallel on two or more different recording layers to obtain an adjustment value, and the relationship between the adjustment value of the first recording layer of the optical disc and the adjustment value of other recording layers in a predetermined optical head; And an optimum adjustment value calculating unit that calculates an adjustment value of the other recording layer of the optical disc in the other optical head from an adjustment value of the first recording layer of the optical disc in the other optical head. The optimum adjustment value calculation unit
The respective optical heads execute calibration in parallel with the first recording layer of the optical disc to obtain the adjustment value, and are recorded on different recording layers other than the first recording layer of the optical disc. Calibration is performed in parallel to obtain the adjustment value, the relationship between the adjustment value of the first recording layer and the adjustment value of the other recording layer of the optical disc in the predetermined optical head, and the other light The optical disc apparatus according to claim 1, wherein an adjustment value of the other recording layer of the optical disc in the other optical head is calculated from an adjustment value of the first recording layer of the optical disc in the head. The optimum adjustment value calculation unit
The difference between the adjustment value of the first recording layer and the adjustment value of the other recording layer of the optical disk in the predetermined optical head is calculated as the adjustment value of the first recording layer of the optical disk in the other optical head. The optical disc apparatus according to claim 1, wherein the adjustment value of the other recording layer of the optical disc in the other optical head is calculated. The optimum adjustment value calculation unit
The ratio of the adjustment value of the first recording layer of the optical disk to the adjustment value of the other recording layer in the predetermined optical head is defined as the adjustment value of the first recording layer of the optical disk in the other optical head. The optical disc apparatus according to claim 1, wherein the adjustment value of the other recording layer of the optical disc in the other optical head is calculated by multiplying by. A light source that emits a light beam;
An objective lens for condensing the light beam on a target recording layer among three or more recording layers provided on an optical disc;
A light receiving unit on which the light beam emitted from the light source and reflected by the optical disc is incident;
With two or more optical heads each having
A first step of executing, in parallel, a calibration for obtaining an optimal adjustment value when adjusting the light beam applied to the target recording layer on the first recording layer of the optical disc;
A second step of performing calibration in parallel with two or more different recording layers other than the first recording layer of the optical disc by each of the two or more optical heads to obtain the adjustment value;
From the relationship between the adjustment value of the first recording layer of the optical disc and the adjustment value of the other recording layer in the predetermined optical head, and the adjustment value of the first recording layer of the optical disc in the other optical head, the other And a third step of calculating an adjustment value of the other recording layer of the optical disc in the optical head.

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