WO2012147129A1

WO2012147129A1 - Optical disk apparatus, optical disk recording and playback method, and optical disk

Info

Publication number: WO2012147129A1
Application number: PCT/JP2011/002463
Authority: WO
Inventors: 無津呂　靖雄; 鈴木　基之; 石飛　竜哉
Original assignee: 日立コンシューマエレクトロニクス株式会社
Priority date: 2011-04-27
Filing date: 2011-04-27
Publication date: 2012-11-01

Abstract

Provided are an optical disk apparatus and optical disk recording and playback method that enable crosstalk from adjacent tracks to be measured and playback adjustments to be easily made for optical disks having a guide layer. At the time of recording, cyclical data is recorded in a portion of a recording layer region (crosstalk amount measurement region) at a position which has nearly the same radial direction and rotational direction as a guide layer address region. At the time of playback, playback is adjusted on the basis of the amount of crosstalk calculated at the crosstalk amount measurement region.

Description

Optical disc apparatus, optical disc recording / reproducing method, optical disc

The present invention relates to an optical disc apparatus for reproducing information from an optical disc using a laser or recording information on the optical disc.

Recently, an optical disc having three or four recording layers has been developed in order to increase the recording capacity. In the future, it is expected that an optical disc having a larger number of recording layers will be developed for the purpose of further increasing the capacity. For example, in Non-Patent Document 1, a layer having a physical groove structure (hereinafter referred to as a guide layer) for performing tracking servo control is provided, and a layer for recording / reproducing (recording layer) does not have a land / groove structure. An optical disc (grooveless disc) is shown, which is easy to manufacture even when a large number of recording layers are stacked.

One of the problems in recording and reproducing the grooveless disk as described above is that crosstalk from adjacent tracks and adjacent layers becomes large, and reproduction adjustment becomes difficult.

The present invention has been made in view of the above-described problems, and an object of the present invention is to measure crosstalk from adjacent tracks in an optical disc having a guide layer, and to easily perform adjustment in reproduction. An information recording / reproducing apparatus and method thereof are provided.

In order to solve the above-described problems, the present invention uses the configuration described in the claims as an example.

According to the present invention, in an optical disc having a guide layer, crosstalk from an adjacent track or an adjacent layer can be measured, and adjustment in reproduction can be easily performed.

FIG. 1 is a diagram showing a configuration example of an optical disc apparatus according to Embodiments 1 to 3 of the present invention. FIG. 2 is a diagram showing a structure example of a grooveless disk according to the first to third embodiments of the present invention. FIG. 3A is a diagram showing an example in which different fixed-period patterns are recorded on adjacent tracks of the fixed-period pattern in the crosstalk measurement area according to the first embodiment of the present invention. FIG. 3B is a diagram illustrating an example in which a mark having a fixed period is recorded on a track adjacent to an unrecorded portion in the crosstalk measurement area according to the first embodiment of the present invention. FIG. 3C is a diagram illustrating an example in which a mark having a fixed period is recorded on an adjacent track of the user data portion in the crosstalk measurement area according to the first embodiment of the present invention. FIG. 4 is a diagram showing the frequency characteristics of the crosstalk measurement region in the first to third embodiments of the present invention. FIG. 5 is a diagram showing an example of focus adjustment in the first to third embodiments of the present invention. FIG. 6 is a diagram showing an example of tilt adjustment in the first and third embodiments of the present invention. FIG. 7 is a diagram showing a configuration example of the decoding circuit in the first to third embodiments of the present invention. FIG. 8 is a diagram showing an example of spherical aberration adjustment in the first to third embodiments of the present invention. FIG. 9A is a diagram showing an example in which different fixed-period patterns are recorded in adjacent layers of the fixed-period pattern in the crosstalk measurement area according to the second embodiment of the present invention. FIG. 9B is a diagram illustrating an example in which marks having a fixed period are recorded in an adjacent layer of an unrecorded portion in the crosstalk measurement area according to the second embodiment of the present invention. FIG. 9C is a diagram illustrating an example in which a fixed-cycle mark is recorded in an adjacent layer of the user data portion in the crosstalk measurement area according to the second embodiment of the present invention. FIG. 10A is a diagram showing an example in which different fixed-period patterns are recorded on adjacent tracks and adjacent layers of the fixed-period pattern in the crosstalk measurement area according to the third embodiment of the present invention. FIG. 10B is a diagram illustrating an example in which marks having a fixed period are recorded on the adjacent track and the adjacent layer of the unrecorded portion in the crosstalk measurement area according to the third embodiment of the present invention. FIG. 10C is a diagram showing an example in which marks having a fixed period are recorded on the adjacent track and the adjacent layer of the non-user data portion in the crosstalk measurement area according to the third embodiment of the present invention. FIG. 11 is a diagram showing an example of the area configuration of the optical disc in the first to third embodiments of the present invention.

FIG. 1 shows a configuration example of an optical disc apparatus as an embodiment of the present invention.

An optical disk device 100 according to the present invention is a device that performs recording or reproduction on a removable optical disk 1 in response to a recording or reproduction request from a host PC 200, and includes an optical pickup 2, a spindle motor 3, a microcomputer 4, an address detection circuit 5, and a cross. The apparatus includes a talk (hereinafter referred to as CT) amount measuring circuit 6, a decoding circuit 7, a memory 8, an encoding circuit 9, and an interface circuit 10.

The optical disc 1 has a guide layer and a recording layer. FIG. 2 schematically shows an example of the structure of the optical disc 1. In the example of FIG. 2, the optical disc 1 has a guide layer 11 and a recording layer 12, and has four recording layers 12. The optical disk apparatus 100 can generate laser spots on the recording layer and the guide layer by the objective lens 21. In FIG. 2, four recording layers are used. However, the number of recording layers is not limited as long as the number of recording layers is one or more. 21, 211, and 212 will be described later.

The optical pickup 2 receives the optical pickup control signal S02 from the microcomputer 4, moves in the radial direction of the optical disc 1 and moves to a recording or reproducing position, and the position of the laser beam focused by the optical pickup control signal S02. Accordingly, the optical disk 1 is irradiated with two laser beams (for example, 405 nm and 650 nm) having different wavelengths for recording or reproduction via the objective lens 21 shown in FIG. The irradiated first laser beam with a wavelength of 650 nm (211 in FIG. 2) is reflected by the guide layer 11 of the optical disc 1 and is not shown in the drawing, which is included in the optical pickup 2 via the objective lens in FIG. Receives the reflected light. The first light receiving unit converts the reflected light into a tracking signal S04 and outputs it to the address detection circuit 5. On the other hand, the irradiated second laser beam having a wavelength of 405 nm (212 in FIG. 2) is reflected by the recording layer 12 of the optical disc 1 during reproduction, and is shown in the optical pickup 2 via the objective lens 21 in FIG. A second light receiving unit not receiving the reflected light. The second light receiving unit converts the reflected light into a reproduction signal S03 and outputs it to the CT amount measuring circuit 6 and the decoding circuit 7. Further, the optical pickup 2 receives the optical pickup control signal S02 from the microcomputer 4 and drives a spherical aberration correction element (not shown) provided in the optical pickup 2 in accordance with the instructed spherical aberration correction amount, thereby converging the laser beam. Control divergence.

The spindle motor 3 receives the motor rotation control from the microcomputer 4 by the motor control signal S01 and rotates the optical disc 1.

The microcomputer 4 controls each circuit of the optical disc device 100. The microcomputer 4 is controlled by software. The microcomputer 4 outputs an optical pickup control signal S02 to the optical pickup 2 at the time of recording / reproduction, and controls the optical pickup 2 to move to the recording / reproducing position by moving in the radial direction of the optical disc 1, thereby adjusting the focus of the laser beam. Control is performed so that the optical disc 1 is irradiated with laser light for recording or reproduction. In addition, the motor control signal S01 is output to the spindle motor 3 to perform motor rotation control and control to rotate the optical disc 1. The microcomputer 4 reads / writes data from / to the memory 8 as appropriate. The number of the microcomputers 4 is not limited to one. For example, a circuit for performing servo control such as the motor control signal S01 and the optical pickup control signal S02 may be provided, and the servo control processing may be separated from the microcomputer 4. Further, the microcomputer 4 controls each circuit of the optical disc apparatus, receives notification of an interrupt signal, a flag signal, etc. from each circuit, and starts processing.

The address detection circuit 5 reads the address information from the tracking signal S04 and outputs a CT amount measurement control signal S05 to the CT amount measurement circuit 6.

The CT amount measurement circuit 6 is controlled by the CT amount measurement control signal S05 to start and end CT amount measurement, calculates a CT amount from the reproduction signal S03, and uses the calculated result as a CT amount calculation result S06. Output to.

The decoding circuit 7 stores the decoding result S07 in the memory 8 by performing analog signal processing such as amplification of the reproduction signal S03 output from the optical pickup 2, digitization, binary data generation and decoding.

The memory 8 is a storage means such as SDRAM (Synchronous Dynamic Random Access Memory) or flash memory, and stores data related to processing in the microcomputer 4.

The encoding circuit 9 performs modulation processing on the recording data S08 in the memory 8 and converts it into binary data stored in the optical disc 1.

The interface circuit 10 communicates with the host PC 200 according to various interface standards such as ATAPI, USB, and IEEE1394, and reads the transmission data S09 from the memory 8 and transmits it to the host PC 200, or receives it from the host PC 200 as reception data S10 in the memory 8. Store.

The recording operation of the optical disc apparatus according to the first embodiment will be described with reference to FIGS.

The recording command and recording data are transmitted from the host PC 200 to the optical disc apparatus 100 and received by the interface circuit 10. The recording data received by the interface circuit 10 is stored in the memory 8 as reception data S10. The reception data S10 stored in the memory 8 is subjected to modulation processing by the encoder circuit 9 and converted into recording data S08. After receiving the recording command reception notification from the interface circuit 10, the microcomputer 4 reads the address information and recording double speed information included in the recording command so that recording can be performed at the recording double speed indicated by the recording double speed information from the position indicated by the address information. A motor control signal S01 and an optical pickup control signal S02 are output to perform recording position control. In the recording position control, the optical pickup 2 emits the first laser light 211 in response to the optical pickup control signal S02. The laser beam 211 is applied to the guide layer 11 of the optical disc 1 through the objective lens 21 and is reflected by the guide layer 11. The reflected light is received by the first light receiving portion of the optical pickup 2 (not shown) via the objective lens 21. The first light receiving section converts the reflected light from the guide layer 11 into a tracking signal S04 and outputs it to the address detection circuit 5. The address detection circuit 5 reads the address from the tracking signal S04 and outputs it to the microcomputer 4. The address is read when the first laser beam is applied to an address area partially provided in the guide layer 11. The microcomputer 4 outputs the optical pickup control signal S02 based on the address and performs recording position control. In the recording position control, the second laser beam 212 may or may not be emitted from the optical pickup 2.

When the microcomputer 4 controls the predetermined recording position, the microcomputer 4 controls the optical pickup 2 so as to record the binary data on the optical disc 1 by the optical pickup control signal S02. In response to the optical pickup control signal S02, the optical pickup 2 emits two types of laser beams having different focal points to the optical disc 1. The first laser beam 211 is applied to the guide layer 11 of the optical disc 1 through the objective lens 21 and is reflected by the guide layer 11. The reflected light is received by the first light receiving portion of the optical pickup 2 (not shown) via the objective lens 21. The first light receiving portion converts the reflected light from the guide layer 11 into a tracking signal S04 and outputs the tracking signal S04. The microcomputer 4 performs the tracking control by outputting the optical pickup control signal S02 based on the tracking signal S04. The tracking signal S04 is also output to the address detection circuit 5. The address detection circuit 5 reads the address from the tracking signal S04 and outputs it to the microcomputer 4. The microcomputer 4 performs address management in the recording operation based on the address and is used for management of the recording data amount. On the other hand, the second laser beam 212 is irradiated onto the recording layer 12 of the optical disc 1 through the objective lens 21 and recorded.

Here, when recording, in the area of the recording layer 12 corresponding to the position of the address area of the guide layer 11, the data to be recorded is not the binary data but the periodic data. FIG. 3A schematically shows the recorded data. In FIG. 3, the same components as those in FIG. Reference numeral 121 in FIG. 3 denotes an area of the recording layer 12 (hereinafter referred to as a CT amount measurement area) corresponding to the position of the address area of the guide layer 11. Reference numeral 1211 denotes periodic data marks recorded in the CT amount measurement area 121. As shown in FIG. 3A, recording is performed such that the period 1211 is different from that of the adjacent track.

FIG. 11 shows a configuration example of the area of the optical disc 1. FIG. 11 shows an example having one guide layer 11 and four recording layers 12. The guide layer 11 includes a guide layer lead-in area 111, a guide layer lead-out area 112, an address area 113, and a guide layer data area 114. Further, the recording layer 12 includes a CT amount measurement region 121, a recording layer lead-in region 122, a recording layer outer region 123, a recording layer inner region 124, a recording layer lead-out region 125, and a recording layer data region 126. The address area 113 of the guide layer and the CT amount measurement area 121 are located at substantially the same address position. The guide layer data area 114 and the recording layer data area 126 are areas for recording user data. The guide layer lead-in area 111, the guide layer lead-out area 112, the recording layer lead-in area 122, the recording layer outer area 123, the recording layer inner area 124, and the recording layer lead-out area 125 are included in the optical disc 1. This is an area for performing test recording and test reproduction for making adjustments for recording and reproduction of control information related to recording and reproduction, and recording and reproduction of user data. With such an optical disc configuration, the CT amount can be calculated for each divided area, and various adjustments can be made in units of areas.

Note that it is not necessary to record periodic data in the area of the recording layer 12 corresponding to the position of all the address areas of the guide layer 11. Instead, the decoding circuit 7 such as user data or management information of the optical disc 1 is used. Decryptable data may be recorded. In this case, the area of the recording layer 12 corresponding to the position of the address area can be effectively used for other purposes.

Next, the reproducing operation of the optical disc apparatus in the first embodiment will be described with reference to FIGS.

The playback command is transmitted from the host PC 200 to the optical disc apparatus 100 and received by the interface circuit 10. After receiving the notification of reception of the reproduction command from the interface circuit 10, the microcomputer 4 reads the address information and reproduction double speed information included in the reproduction command so that reproduction can be performed at the reproduction double speed indicated by the reproduction double speed information from the position indicated by the address information. A motor control signal S01 and an optical pickup control signal S02 are output to perform reproduction position control. Since the operation of the reproduction position control is the same as that of the recording position control, the description is omitted. In the reproduction position control, the second laser beam 212 may or may not be emitted from the optical pickup 2 as in the recording position control.

The microcomputer 4 controls the optical pickup 2 so as to reproduce the optical disc 1 by the optical pickup control signal S02 when the microcomputer 4 controls the predetermined reproduction position. In response to the optical pickup control signal S02, the optical pickup 2 emits two types of laser beams having different focal points to the optical disc 1. Since the operation related to the first laser beam 211 is the same as the operation related to the first laser beam 211 in the recording operation, a description thereof will be omitted. On the other hand, the second laser beam 212 is applied to the recording layer 12 of the optical disc 1 through the objective lens 21 and reflected by the recording layer 12. The reflected light is received by the second light receiving portion of the optical pickup 2 (not shown) via the objective lens 21. The second light receiving unit converts the reflected light from the recording layer 12 into a reproduction signal S03 and outputs it to the decoding circuit 7 and the CT amount measuring circuit 6. The decoding circuit 7 performs analog signal processing such as amplification of the reproduction signal S03, digitization, binary data generation, and decoding to generate a decoding result S07 and stores it in the memory 8. The decoding result S07 stored in the memory 8 is read by the interface circuit 10 and output to the host PC 200. Note that the optical pickup position control at the time of reproduction may be performed by a signal based on the reflected light from the recording layer 12 by the second laser beam 212. In this case, for example, only the second laser beam needs to be emitted in the read-only optical disc apparatus, and it is not necessary to emit the first laser beam, so that the configuration of the optical pickup 2 can be simplified.

Here, during reproduction, CT amount measurement is performed during the time during which the CT amount measurement region 121 shown in FIG. 3 is being reproduced. In the CT amount measurement area 121, periodic data is recorded as described above, and data having a period different from that of adjacent tracks is recorded. The CT amount is calculated based on the frequency characteristics of the reproduction signal S03 obtained when the CT amount measurement region 121 is reproduced. An example of the frequency characteristic of the reproduction signal S03 in the CT amount measurement region 121 is shown in FIG. As shown in FIG. 4, the ideal frequency characteristic is a characteristic having a peak in the frequency (ftarget) of the periodic data on the track being reproduced and the frequency (fside) of the periodic data on the adjacent track. Become. At this time, it is assumed that the signal intensity Pside at fside is the CT amount. The characteristic shown in FIG. 4 is an example of an ideal frequency characteristic, and the signal intensity can actually take a non-zero (not zero) value at other frequencies. In calculating the CT amount, the signal intensity at fside is used as the CT amount. However, the signal intensity that is maximal at the frequency near fside may be used as the CT amount, or the amount obtained by integrating the signal intensity at the frequency near fside is the CT amount. It is also good. The CT amount calculated in this way is output to the microcomputer 4 as a CT amount calculation result S06.

The microcomputer 4 performs various adjustment processes based on the CT amount calculation result S06.

For example, in focus adjustment, reproduction is performed by changing several focus positions, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the focus position where the calculated CT amount is minimized is used as the focus adjustment result. . As the focus position shifts, the spot of the laser beam 212 is blurred and widens in diameter, and the CT amount tends to increase. For this reason, when the CT amount characteristic with respect to the focus position is taken, it becomes a characteristic having a minimum point. Although the CT amount measurement area 121 on the same track is used, as long as the data frequency of the CT amount measurement area 121 is the same, the track may not be the same, or the same CT amount measurement area 121 may be used. Further, when obtaining the focus position at which the CT amount is minimized, the characteristic of the CT amount with respect to the focus position may be obtained, and the focus adjustment result may be calculated by an approximate method. FIG. 5 shows an example of focus adjustment in this case. The CT amounts measured by regenerating the CT amount measurement region 121 by changing the focus position at four positions Fa, Fb, Fc, and Fd are Pa, Pb, Pc, and Pd, respectively. When curve approximation is performed from these four points and the obtained minimum value is Pmini, a focus position Fbest that takes the value of Pmini in the approximate expression is taken as a focus adjustment result.

In tilt adjustment, reproduction is performed by changing the tilt position at several places, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the tilt position where the calculated CT amount is minimized is used as the tilt adjustment result. . When the tilt position is shifted, the spot of the second laser beam 212 is shifted from the track, and the CT amount tends to increase. For this reason, when the CT amount characteristic with respect to the tilt position is taken, it becomes a characteristic having a minimum point. Although the CT amount measurement area 121 on the same track is used, as long as the data frequency of the CT amount measurement area 121 is the same, the track may not be the same, or the same CT amount measurement area 121 may be used. Further, when obtaining the tilt position at which the CT amount is minimized, the characteristic of the CT amount with respect to the tilt position may be obtained, and the tilt adjustment result may be calculated by an approximate method. FIG. 6 shows an example of tilt adjustment in this case. The CT amounts measured by reproducing the CT amount measurement region 121 by changing the tilt position at four locations of Ta, Tb, Tc, and Td are defined as Pa, Pb, Pc, and Pd, respectively. When curve approximation is performed from these four points and the obtained minimum value is Pmini, the tilt position Tbest at which the value of Pmini is obtained in the approximate expression is defined as a tilt adjustment result.

Further, in the power adjustment (hereinafter referred to as read power) of the second laser beam 212 at the time of reproduction, reproduction is performed by changing the read power by several stages, and the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, The read power determined based on the calculated CT amount is taken as a read power adjustment result. Since the signal amplitude also changes when the read power is changed, the ratio of Ptarget to Pside in FIG. 4 (hereinafter referred to as CT ratio) is used as an index for adjusting the read power. When the read power changes, the spot of the second laser beam 212 may increase or change its shape, and the CT ratio may change. For this reason, when the characteristic of the CT ratio with respect to the read power is taken, there may be a characteristic having a minimum point. Although the CT amount measurement area 121 on the same track is used, as long as the data frequency of the CT amount measurement area 121 is the same, the track may not be the same, or the same CT amount measurement area 121 may be used. Further, when obtaining the read power at which the CT ratio is minimized, the characteristics of the CT ratio with respect to the read power may be obtained, and the read power adjustment result may be calculated by an approximate method.

Also, the CT amount is used in the processing in the decoding circuit 7. FIG. 7 shows an example of the configuration of the decoding circuit 7. The analog signal processing circuit 71 that performs analog signal processing such as amplification of the reproduction signal S03 and digitization of the processing result signal of the analog signal processing circuit 71 are shown. An A / D (Analog to Digital) conversion circuit 72 to perform, an adaptive equalization circuit 73 that adaptively equalizes a digital signal output from the A / D conversion circuit 72, and an equalization signal output from the adaptive equalization circuit 73 And an adaptive maximum likelihood decoding circuit 74 that adaptively performs a maximum likelihood decoding algorithm (for example, a Viterbi algorithm) and generates binary data, and a demodulation circuit 75 that performs a demodulation process of the binary data.

Here, in the adaptive equalization circuit 73, the coefficient of each tap of the FIR (Finite Impulse Response) filter is the convolution signal obtained from the target signal of the binarized bit string and the RMS of the equalization signal output from the adaptive equalization circuit 73 ( Root Mean Square) The learning process is performed so as to minimize the error. The tap coefficient convergence speed in the learning process is variably controlled based on the magnitude of the CT amount. For example, when the CT amount is large, the error becomes large and there is a concern that the influence on the learning process will be large. Therefore, the convergence speed of the tap coefficient is slowed down. Conversely, when the CT amount is small, the influence on the learning process is small, so the tap coefficient convergence speed is increased. Although the RMS error is used, an error obtained by another calculation such as an absolute value may be used.

In addition, the adaptive maximum likelihood decoding circuit 74 generates binary data from the equalized signal using a maximum likelihood decoding algorithm such as a Viterbi algorithm. In the Viterbi algorithm, the distance between the target level, which is an amplitude value that can be taken by the target waveform obtained by convolving the target binary signal sequence, and the amplitude value of the equalized signal is sequentially integrated, and the distance 2 is the smallest. Binary data for generating a value code pattern is used. The adaptive maximum likelihood decoding circuit 74 variably controls the target level to follow the target level according to the characteristics of the input equalized signal, and variably changes the follow-up speed based on the CT amount. That is, when the CT amount is large, the distance to the amplitude value of the equalized signal is increased, and there is a concern that the influence on the control processing of the target level is increased. Conversely, when the CT amount is small, the effect on the control process is small, and therefore the follow-up speed is increased.

In the spherical aberration adjustment, the spherical aberration correction amount is reproduced by changing several stages, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the spherical aberration correction amount at which the calculated CT amount is minimized is obtained. The result is a spherical aberration adjustment result. When the spherical aberration correction amount is not optimal, the spot of the laser beam 212 is blurred and widened in diameter, and the CT amount tends to increase. For this reason, when the CT amount characteristic with respect to the spherical aberration correction amount is taken, the characteristic has a minimum point. Although the CT amount measurement area 121 on the same track is used, as long as the data frequency of the CT amount measurement area 121 is the same, the track may not be the same, or the same CT amount measurement area 121 may be used. Further, when obtaining the spherical aberration correction amount that minimizes the CT amount, the characteristic of the CT amount with respect to the spherical aberration correction amount may be obtained, and the focus adjustment result may be calculated by an approximate method. FIG. 8 shows an example of spherical aberration adjustment in this case. The CT amounts measured by reproducing the CT amount measurement region 121 by changing the spherical aberration correction amount at four locations ABa, ABb, ABc, and ABd are Pa, Pb, Pc, and Pd, respectively. When curve approximation is performed from these four points and the obtained minimum value is Pmini, the spherical aberration correction amount ABbest that takes the value of Pmini in the approximate expression is taken as the spherical aberration correction result.

In the present embodiment, the data recorded in the CT amount measurement area 121 has a period of periodic data marks different from that of the adjacent track as shown in FIG. 3A, but as shown in FIG. Alternatively, periodic data marks may be recorded on adjacent tracks of the unrecorded portion. In this case, the CT amount is measured during the time when the unrecorded part is reproduced. At this time, the ideal frequency characteristic has a peak at the frequency of the periodic data on the adjacent track, and the signal intensity of the peak value is the CT amount. In FIG. 3B, an unrecorded portion and a periodic data recording portion are provided in the same track in the CT amount measurement region 121, but an unrecorded portion is present in the same track in the CT amount measurement region 121. However, a periodic data mark recording unit may be provided in another CT amount measurement region 121 on the same track.

In the present embodiment, the data recorded in the CT amount measurement area 121 has a period of periodic data marks different from that of the adjacent track as shown in FIG. 3A, but as shown in FIG. In addition, periodic data marks may be recorded on adjacent tracks in the user data portion. In this case, the CT amount measurement is performed during the time when the user recording unit is being reproduced. At this time, the ideal frequency characteristic has a peak at the frequency of the periodic data on the adjacent track, and the signal intensity is small at other frequencies. Let the signal intensity of the peak value be the CT amount. In FIG. 3C, the user data portion and the periodic data recording portion are provided in the same track in the CT amount measurement region 121, but the user data portion is provided in the same track in the CT amount measurement region 121. However, a periodic data mark recording unit may be provided in another CT amount measurement region 121 on the same track.

The recording operation of the optical disk apparatus in the second embodiment will be described with reference to FIGS.

Since the recording command and the recording data are transmitted from the host PC 200 to the optical disc apparatus 100 and the operation of the optical disc apparatus 100 recording on the optical disc 1 is the same as in the first embodiment except for the recording in the CT amount measurement area, the explanation will be given. Omitted.

In Example 2, when recording is performed, in the area of the recording layer 12 corresponding to the position of the address area of the guide layer 11, data to be recorded is not the binary data but periodic data. FIG. 9A schematically shows the recorded data. In FIG. 9, the same components as those in FIG. As shown in FIG. 9A, recording is performed such that the period of the periodic data mark 1211 is different from the CT amount measurement area 121 of the track at the radial position of the optical disc 1 in which the adjacent layer is substantially equal.

Next, the reproducing operation of the optical disk apparatus according to the second embodiment will be described with reference to FIGS. 1, 2, 4, 5 and FIGS.

Since the playback command is transmitted from the host PC 200 to the optical disc device 100 and the optical disc device 100 performs playback from the optical disc 1 is the same as in the first embodiment except for the playback of the CT amount measurement region, description thereof is omitted.

In Example 2, during reproduction, CT amount measurement is performed during the time during which the CT amount measurement region 121 shown in FIG. 9 is being reproduced. In the CT amount measurement region 121, periodic data is recorded as described above, and data having a period different from the periodic data of the track at the radial position of the optical disc 1 in the adjacent layer that is substantially equal is recorded. The CT amount is calculated based on the frequency characteristics of the reproduction signal S03 obtained when the CT amount measurement region 121 is reproduced. An example of the frequency characteristic of the reproduction signal S03 in the CT amount measurement region 121 can be shown as in FIG. As shown in FIG. 4, the ideal frequency characteristic is that the periodic data on the track at the radial position of the optical disc 1 in the adjacent layer is substantially equal to the frequency (ftarget) of the periodic data on the track being reproduced. It has a characteristic having a peak at the frequency (fside). At this time, it is assumed that the signal intensity Pside at fside is the CT amount. The characteristic shown in FIG. 4 is an example in the case of an ideal frequency characteristic, and the signal intensity can actually take a non-zero value at other frequencies. In calculating the CT amount, the signal intensity at fside is used as the CT amount. However, the signal intensity that is maximal at the frequency near fside may be used as the CT amount, or the amount obtained by integrating the signal intensity at the frequency near fside is the CT amount. It is also good. The CT amount calculated in this way is output to the microcomputer 4 as a CT amount calculation result S06.

For example, in focus adjustment, reproduction is performed by changing several focus positions, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the focus position where the calculated CT amount is minimized is used as the focus adjustment result. . As the focus position shifts, the focal point of the laser beam 212 moves to the adjacent layer side, and the CT amount tends to increase. For this reason, when the CT amount characteristic with respect to the focus position is taken, it becomes a characteristic having a minimum point. Although the CT amount measurement area 121 on the same track is used, as long as the data frequency of the CT amount measurement area 121 is the same, the track may not be the same, or the same CT amount measurement area 121 may be used. Further, when obtaining the focus position at which the CT amount is minimized, the characteristic of the CT amount with respect to the focus position may be obtained, and the focus adjustment result may be calculated by an approximate method. Since the example in this case can be described using FIG. 5 similarly to the first embodiment, the description is omitted.

Also, the CT amount is used in the processing in the decoding circuit 7. A configuration example of the decoding circuit 7 in the second embodiment can be shown in FIG. 7 as in the first embodiment. As in the first embodiment, the adaptive equalization circuit 73 variably controls the tap coefficient convergence speed in the learning process based on the CT amount. In the adaptive maximum likelihood decoding circuit 74, the target level is variably controlled in the same manner as in the first embodiment so as to follow the target level according to the characteristics of the input equalized signal, and is variable based on the CT amount. Change the following speed.

In the spherical aberration adjustment, the spherical aberration correction amount is reproduced by changing several stages, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the spherical aberration correction amount at which the calculated CT amount is minimized is obtained. The result is a spherical aberration adjustment result. If the spherical aberration correction amount is not optimal, the focal point of the laser beam 212 moves to the adjacent layer side, and the CT amount tends to increase. For this reason, when the CT amount characteristic with respect to the spherical aberration correction amount is taken, the characteristic has a minimum point. Although the CT amount measurement area 121 on the same track is used, as in the first embodiment, if the frequency of data in the CT amount measurement area 121 is the same track, the CT track may not be the same track. The region 121 may be used. Further, when obtaining the spherical aberration correction amount that minimizes the CT amount, the characteristic of the CT amount with respect to the spherical aberration correction amount may be obtained, and the spherical aberration adjustment result may be calculated by an approximate method. Since the example in this case can be described using FIG. 8 similarly to the first embodiment, the description is omitted.

In this embodiment, the data recorded in the CT amount measurement area 121 is different from the track of the radial position of the optical disc 1 in which the adjacent layer has substantially the same period as shown in FIG. 9A. However, as shown in FIG. 9B, periodic data marks may be recorded on the track at the radial position of the optical disc 1 that is substantially the same in the adjacent layer of the unrecorded portion. In this case, the CT amount is measured during the time when the unrecorded part is reproduced. At this time, the ideal frequency characteristic is a characteristic having a peak at the frequency of the periodic data on the track at the radial position of the optical disc 1 in the adjacent layer which is substantially equal, and the signal intensity of the peak value is the CT amount. In FIG. 9B, an unrecorded portion and a periodic data recording portion are provided in the same track in the CT amount measurement region 121, but an unrecorded portion is present in the same track in the CT amount measurement region 121. However, a periodic data mark recording unit may be provided in another CT amount measurement region 121 on the same track. Further, when reproducing the unrecorded portion, if the pickup position control is performed with a signal based on the reflected light from the recording layer 12 by the second laser beam 212, the position control becomes unstable, so that the control is performed. Even if the operation is switched so that the parameter is fixed to the parameter value at the time of reproducing the recording part, or only the unrecorded part is controlled by the signal based on the reflected light from the guide layer 21 by the first laser beam 211. good.

In this embodiment, the data recorded in the CT amount measurement area 121 is different from the track of the radial position of the optical disc 1 in which the adjacent layer has substantially the same period as shown in FIG. 9A. However, as shown in FIG. 9C, periodic data marks may be recorded on the track at the radial position of the optical disk 1 that is substantially equal in the adjacent layer of the user data portion. In this case, the CT amount measurement is performed during the time when the user recording unit is being reproduced. At this time, the ideal frequency characteristic has a peak at the frequency of the periodic data on the track at the radial position of the optical disc 1 in the adjacent layer which is substantially equal, and the signal intensity is small at other frequencies. Let the signal intensity of the peak value be the CT amount. In FIG. 9C, the user data portion and the periodic data recording portion are provided in the same track in the CT amount measurement region 121, but the user data portion is provided in the same track in the CT amount measurement region 121. However, a periodic data mark recording unit may be provided in another CT amount measurement region 121 on the same track.

The recording operation of the optical disc apparatus in the third embodiment will be described with reference to FIGS.

In Example 3, when recording is performed, in the area of the recording layer 12 corresponding to the position of the address area of the guide layer 11, the data to be recorded is not the binary data but periodic data. FIG. 10A schematically shows the recorded data. 10, the same numbers are assigned to the same components as those in FIG. As shown in FIG. 10A, the period of the periodic data mark 1211 is recorded so as to be different from the CT amount measurement region 121 of the adjacent track and the track at the radial position of the optical disk 1 that is substantially the same in the adjacent layer. I do.

Next, the reproducing operation of the optical disk apparatus according to the third embodiment will be described with reference to FIGS.

In Example 3, during reproduction, CT amount measurement is performed during the time during which the CT amount measurement region 121 shown in FIG. 10 is being reproduced. In the CT amount measurement area 121, periodic data is recorded as described above, and data having a period different from the periodic data of the adjacent track and the track at the radial position of the optical disc 1 that is substantially the same in the adjacent layer is recorded. Has been. The CT amount is calculated based on the frequency characteristics of the reproduction signal S03 obtained when the CT amount measurement region 121 is reproduced. An example of the frequency characteristic of the reproduction signal S03 in the CT amount measurement region 121 can be shown as in FIG. As shown in FIG. 4, the ideal frequency characteristic is such that the frequency (ftarget) of the periodic data on the track being reproduced and the track on the radial position of the optical disc 1 which is substantially equal to the adjacent track and the adjacent layer. It has a characteristic having a peak at the frequency (fside) of the periodic data. At this time, it is assumed that the signal intensity Pside at fside is the CT amount. The characteristic shown in FIG. 4 is an example in the case of an ideal frequency characteristic, and the signal intensity can actually take a non-zero value at other frequencies. In calculating the CT amount, the signal intensity at fside is used as the CT amount. However, the signal intensity that is maximal at the frequency near fside may be used as the CT amount, or the amount obtained by integrating the signal intensity at the frequency near fside is the CT amount. It is also good. The CT amount calculated in this way is output to the microcomputer 4 as a CT amount calculation result S06.

For example, in focus adjustment, reproduction is performed by changing several focus positions, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the focus position where the calculated CT amount is minimized is used as the focus adjustment result. . As the focus position shifts, the spot of the laser beam 212 blurs and increases in diameter in the layer, and the focal point moves toward the adjacent layer, and the amount of CT from the adjacent track or adjacent layer tends to increase. For this reason, when the CT amount characteristic with respect to the focus position is taken, it becomes a characteristic having a minimum point. Although the CT amount measurement area 121 on the same track is used, as long as the data frequency of the CT amount measurement area 121 is the same, the track may not be the same, or the same CT amount measurement area 121 may be used. Further, when obtaining the focus position at which the CT amount is minimized, the characteristic of the CT amount with respect to the focus position may be obtained, and the focus adjustment result may be calculated by an approximate method. Since the example in this case can be described using FIG. 5 similarly to the first embodiment, the description is omitted.

In tilt adjustment, reproduction is performed by changing the tilt position at several places, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the tilt position where the calculated CT amount is minimized is used as the tilt adjustment result. . Since the tilt adjustment method is the same as that of the first embodiment, description thereof is omitted.

Further, in the power adjustment (hereinafter referred to as read power) of the second laser beam 212 at the time of reproduction, reproduction is performed by changing the read power by several stages, and the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, The read power determined based on the calculated CT amount is taken as a read power adjustment result. Since the read power adjustment method is the same as that of the first embodiment, the description thereof is omitted.

Also, the CT amount is used in the processing in the decoding circuit 7. A configuration example of the decoding circuit 7 in the third embodiment can be shown in FIG. 7 as in the first embodiment. As in the first embodiment, the adaptive equalization circuit 73 variably controls the tap coefficient convergence speed in the learning process based on the CT amount. In the adaptive maximum likelihood decoding circuit 74, the target level is variably controlled in the same manner as in the first embodiment so as to follow the target level according to the characteristics of the input equalized signal, and is variable based on the CT amount. Change the following speed.

In the spherical aberration adjustment, the spherical aberration correction amount is reproduced by changing several stages, the frequency characteristics in the CT amount measurement region 121 on the same track are calculated, and the spherical aberration correction amount at which the calculated CT amount is minimized is obtained. The result is a spherical aberration adjustment result. When the spherical aberration correction amount is not optimal, the spot of the laser beam 212 is blurred and the diameter is widened, and the focal point moves to the adjacent layer side, and the CT amount from the adjacent track and the adjacent layer tends to increase. For this reason, when the CT amount characteristic with respect to the spherical aberration correction amount is taken, the characteristic has a minimum point. Although the CT amount measurement area 121 on the same track is used, as in the first embodiment, if the frequency of data in the CT amount measurement area 121 is the same track, the CT track may not be the same track. The region 121 may be used. Further, when obtaining the spherical aberration correction amount that minimizes the CT amount, the characteristic of the CT amount with respect to the spherical aberration correction amount may be obtained, and the spherical aberration adjustment result may be calculated by an approximate method. Since the example in this case can be described using FIG. 8 similarly to the first embodiment, the description is omitted.

In this embodiment, the data to be recorded in the CT amount measurement area 121 is the track of the radial position of the optical disc 1 in which the period of the periodic data mark is substantially equal between the adjacent track and the adjacent layer as shown in FIG. However, as shown in FIG. 10B, periodic data marks may be recorded on the adjacent track of the unrecorded portion and the track at the radial position of the optical disc 1 that is substantially the same in the adjacent layer. In this case, the CT amount is measured during the time when the unrecorded part is reproduced. At this time, the ideal frequency characteristic is a characteristic having a peak at the frequency of the periodic data on the track at the radial position of the optical disc 1 in which the adjacent track and the adjacent layer are substantially equal, and the signal intensity of the peak value is the CT amount. . In FIG. 10B, in the CT amount measurement region 121, an unrecorded portion and a periodic data recording portion are provided in the same track. However, in the CT amount measurement region 121, an unrecorded portion is provided in the same track. However, a periodic data mark recording unit may be provided in another CT amount measurement region 121 on the same track.

In this embodiment, the data to be recorded in the CT amount measurement area 121 is the track of the radial position of the optical disc 1 in which the period of the periodic data mark is substantially equal between the adjacent track and the adjacent layer as shown in FIG. Although different, as shown in FIG. 10C, periodic data marks may be recorded on the adjacent tracks in the user data portion and the tracks at the radial positions of the optical disc 1 that are substantially equal in the adjacent layers. In this case, the CT amount measurement is performed during the time when the user recording unit is being reproduced. At this time, the ideal frequency characteristic has a peak at the frequency of the periodic data on the track at the radial position of the optical disc 1 in which the adjacent track and the adjacent layer are substantially equal, and the signal intensity is low at other frequencies. Let the signal intensity of the peak value be the CT amount. In FIG. 10C, the user data portion and the periodic data recording portion are provided in the same track in the CT amount measurement region 121, but the user data portion is provided in the same track in the CT amount measurement region 121. However, a periodic data mark recording unit may be provided in another CT amount measurement region 121 on the same track.

In the first to third embodiments, the configuration of the optical disc device 100 is realized by a circuit, but a part may be realized by software. In this case, the same effect as that realized by a circuit can be obtained.

Further, in the first to third embodiments, at least a part of the operation of the software that operates on the microcomputer may be realized by a circuit. In this case, the same effect as that realized by software can be obtained.

In the first to third embodiments, the optical disc apparatus 100 performs the recording operation and the reproducing operation. However, the optical disc apparatus 100 may be an apparatus dedicated to recording or reproduction. If it is a recording-only device, the CT amount measuring circuit 6 and the decoding circuit 7 may be omitted in the configuration of the optical disk device 100 of FIG. Further, the encoding circuit 9 may be omitted if it is a reproduction-only device.

In the first to third embodiments, the adjustment is performed based on the minimum value of the CT amount and the CT ratio in various adjustments such as focus adjustment and tilt adjustment. Adjustments may be made based on being below or below the threshold.

Further, adjustment processing such as focus adjustment in the first to third embodiments may be performed, for example, at the time of setting up the optical disc apparatus, or may be performed in other cases.

DESCRIPTION OF SYMBOLS 100 ... Optical disk apparatus 200 ... Host PC
DESCRIPTION OF SYMBOLS 1 ... Optical disk 11 ... Guide layer 111 ... Guide layer Lead-in area 112 ... Guide layer Lead-out area 113 ... Address area 114 ... Guide layer data area 12 ... Recording layer 121 ... CT amount measurement area 122 ... Recording layer Lead-in Area 123 ... Recording layer Outer area 124 ... Recording layer Inner area 125 ... Recording layer Lead-out area 126 ... Recording layer data area 2 ... Optical pickup 21 ... Objective lens 211 ... First laser beam 212 ... Second laser beam 3 DESCRIPTION OF SYMBOLS ... Spindle motor 4 ... Microcomputer 5 ... Address detection circuit 6 ... Crosstalk amount measurement circuit 7 ... Decoding circuit 8 ... Memory 9 ... Encoding circuit 10 ... Interface circuit S01 ... Motor control signal S02 ... Optical pick-up control signal S03 ... Reproduction signal S04 ... Tracking signal S05 CT amount measurement control signal S06 ... CT value calculation result S07 ... decoding result S08 ... recording data S09 ... transmission data S10 ... Receive Data

Claims

In an optical disc apparatus for reproducing an optical disc medium having a guide layer and n recording layers (n ≧ 1 natural number),
An optical pickup that emits laser light that irradiates the recording layer of the optical disc medium, converts the reflected light reflected by the recording layer into an electrical signal, and outputs the electrical signal;
A decoding circuit that generates a binary data by performing a decoding process based on the electric signal output from the optical pickup or a signal obtained by performing a signal process on the electric signal;
A crosstalk amount measuring circuit for calculating a crosstalk amount based on the electrical signal output from the optical pickup or a signal obtained by performing signal processing on the electrical signal;
A control circuit for controlling reproduction adjustment processing for reproducing the optical disk medium based on the crosstalk amount calculated by the crosstalk amount measuring circuit;
The optical disk apparatus, wherein the crosstalk amount measuring circuit calculates a crosstalk amount based on a frequency characteristic of the electrical signal or an electrical signal obtained by performing signal processing on the electrical signal.
The crosstalk amount measuring circuit calculates a frequency spectrum of the electrical signal or an electrical signal obtained by performing signal processing on the electrical signal, and the second largest signal strength value or the largest signal strength value in the frequency spectrum. 2. The optical disk apparatus according to claim 1, wherein a crosstalk amount is used.
The crosstalk amount measurement circuit calculates a frequency spectrum of the electrical signal or an electrical signal obtained by performing signal processing on the electrical signal, and the periodic data recorded on the track being reproduced in the frequency spectrum. The integrated value of the signal intensity at a frequency excluding the frequency substantially equal to the frequency of the signal, or the signal intensity at a frequency substantially equal to the frequency of the periodic data recorded on the track being reproduced is used as the crosstalk amount. The optical disc apparatus according to claim 1.
The control circuit is characterized in that a focus position at which the crosstalk amount is substantially minimized is set as a focus adjustment result, or a spherical aberration correction position at which the crosstalk amount is substantially minimized is set as a spherical aberration correction result. The optical disk apparatus according to claim 1, wherein a tilt position where the crosstalk amount is substantially minimum is set as a tilt adjustment result.
The decoding circuit includes an adaptive equalization circuit that adaptively performs equalization of the electric signal output from the optical pickup or a signal obtained by performing signal processing on the electric signal, and the tap coefficient of the adaptive equalization circuit An adaptive method for generating a binary data from an equalized signal output from an adaptive equalization circuit or a signal obtained by signal processing the equalized signal, wherein the convergence speed is changed based on the crosstalk amount A maximum likelihood decoding circuit is provided, and the speed at which the target level in the adaptive maximum likelihood decoding circuit is made to follow the target level according to the characteristics of the input equalized signal is changed based on the crosstalk amount. 1. An optical disc device according to 1.
In an optical disc apparatus for recording data on an optical disc medium having a guide layer and n recording layers (n ≧ 1 natural number),
An optical pickup that emits a laser beam that irradiates the guide layer of the optical disc medium and a laser beam that irradiates one of the recording layers, converts the reflected light reflected by the guide layer into an electrical signal, and outputs the electrical signal. When,
An address detection circuit for detecting an address based on the signal obtained by performing signal processing on the electrical signal or the electrical signal by the reflected light in the address region of the guide layer;
A control circuit for controlling the optical pickup to emit the laser beam for recording data on the recording layer;
The control circuit records periodic data in a part of the area of the recording layer (crosstalk amount measurement area) at a position in the radial direction and rotation direction substantially equal to the address area detected by the address detection circuit. An optical disc apparatus for controlling the optical pickup so as to emit the laser beam for the purpose.
The control circuit records data having different periods on adjacent tracks of a part of periodic data in the crosstalk amount measurement area, or has m recording layers (m ≧ 2 natural number). 7. The optical disc apparatus according to claim 6, wherein data having a different period is recorded on a track of an adjacent layer of a part of periodic data in the crosstalk amount measurement area in the optical disc medium having the optical disc medium.
The control circuit records periodic data on an adjacent track of non-periodic data in the crosstalk amount measurement region, or has m recording layers (m ≧ 2 natural number). 7. The optical disc apparatus according to claim 6, wherein periodic data is recorded on a track of an adjacent layer of non-periodic data in the crosstalk amount measurement area in the optical disc medium.
The control circuit records periodic data on a track adjacent to a track on which no data is recorded in the crosstalk amount measurement area, or has m recording layers (m ≧ 2 natural number). 7. The optical disc apparatus according to claim 6, wherein periodic data is recorded on a track in a layer adjacent to a track on which no data is recorded in the crosstalk amount measurement area in the optical disc medium.
In an optical disc reproducing method for reproducing an optical disc medium having a guide layer and n recording layers (n ≧ 1 natural number),
Emitting a laser beam that irradiates the recording layer of the optical disc medium, and converting the reflected light reflected by the recording layer into an electrical signal;
Decoding processing is performed based on the electric signal or a signal obtained by signal processing of the electric signal, binary data is generated, and the frequency characteristics of the electric signal or the signal obtained by signal processing of the electric signal Calculate the amount of crosstalk based on
An optical disc reproducing method for performing reproduction adjustment processing for reproducing the optical disc medium based on the crosstalk amount.
In the measurement of the crosstalk amount, a frequency spectrum of the electric signal or an electric signal obtained by performing signal processing on the electric signal is calculated, and the second largest signal intensity value or the largest signal intensity value in the frequency spectrum 11. The method of reproducing an optical disk according to claim 10, wherein a crosstalk amount is used.
In the measurement of the crosstalk amount, a frequency spectrum of the electrical signal or an electrical signal obtained by performing signal processing on the electrical signal is calculated, and periodic data recorded on the track being reproduced in the frequency spectrum. The integrated value of the signal intensity at a frequency excluding the frequency substantially equal to the frequency of the signal, or the signal intensity at a frequency substantially equal to the frequency of the periodic data recorded on the track being reproduced is used as the crosstalk amount. The optical disk reproducing method according to claim 10.
In the reproduction adjustment processing, a focus position at which the crosstalk amount is substantially minimized is set as a focus adjustment result, or a spherical aberration correction position at which the crosstalk amount is substantially minimized is set as a spherical aberration correction result. 11. The optical disk reproducing method according to claim 10, wherein a tilt position at which the crosstalk amount is substantially minimized is set as a tilt adjustment result.
In the decoding process, an adaptive equalization process that adaptively performs equalization of the electric signal output from the optical pickup or a signal obtained by signal processing of the electric signal, and tap coefficients in the adaptive equalization process The convergence speed is changed based on the crosstalk amount, or binary data is generated from an equalized signal that is an adaptive equalization processing result or a signal obtained by signal processing the equalized signal The adaptive maximum likelihood decoding process is performed, and the speed at which the target level in the adaptive maximum likelihood decoding process follows the target level according to the characteristics of the input equalized signal is changed based on the crosstalk amount. The optical disc reproducing method according to 10.
In an optical disc recording method for recording data on an optical disc medium having a guide layer and n recording layers (n ≧ 1 natural number),
Emitting laser light applied to the guide layer of the optical disc medium and laser light applied to any one of the recording layers, and converting the reflected light reflected by the guide layer into an electrical signal;
Detecting an address based on the signal obtained by signal processing the electrical signal or the electrical signal by the reflected light in the address region of the guide layer;
Emitting the laser beam for recording data on the recording layer;
The laser beam for recording periodic data is emitted to a part of the area of the recording layer (crosstalk amount measuring area) at a position in the radial direction and rotational direction substantially equal to the address area for detecting the address. An optical disc recording method.
In the optical disk medium having m recording layers (m ≧ 2 natural number), data having different periods are recorded on adjacent tracks of some periodic data in the crosstalk amount measurement region 16. The optical disk recording method according to claim 15, wherein data having a different period is recorded on a track of an adjacent layer of a part of periodic data in the crosstalk amount measurement region.
In the crosstalk amount measurement area, periodic data is recorded on an adjacent track of non-periodic data, or the crossing in the optical disk medium having m recording layers (m ≧ 2 natural number) 16. The optical disk recording method according to claim 15, wherein the periodic data is recorded on the track of the adjacent layer of the non-periodic data in the talk amount measurement area.
In the crosstalk amount measurement region, periodic data is recorded on a track adjacent to a track on which no data is recorded, or in the optical disk medium having m recording layers (m ≧ 2 natural number) 16. The optical disk recording method according to claim 15, wherein periodic data is recorded on a track in a layer adjacent to a track on which no data is recorded in the crosstalk amount measurement region.
In an optical disc medium having a guide layer and n recording layers (n ≧ 1 natural number), periodic data is recorded in a part of the recording layer region at a position in the radial direction and the rotational direction substantially equal to the address region of the guide layer. Recorded optical disk medium.