JP3762027B2 - Optical disc, optical disc playback apparatus, optical disc playback method, and optical disc recording method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disc recording / reproducing apparatus and an optical disc recording / reproducing method for recording data on an optical disc capable of recording data on both a spiral land track and a groove track or reproducing the recorded data.
[0002]
[Prior art]
Some optical discs can record data on only one of a land track and a groove track, and others can record data on both a land track and a groove track.
[0003]
In the latter case, at the time of data recording / reproducing, it is necessary to identify the land track and the groove track and switch between land tracking corresponding to the land track and groove tracking corresponding to the groove track.
Conventionally, a land track and a groove track are identified in an analog manner from the characteristics of a reproduction signal reproduced from an optical disk.
[0004]
[Problems to be solved by the invention]
In the case of analog identification as described above, there is a problem in the identification accuracy because the corn is easily affected by scratches on the optical disk or meandering of the beam. For this reason, land tracking and groove tracking may be erroneously switched due to erroneous detection.
[0005]
An object of the present invention is to provide an optical disc recording / reproducing apparatus and an optical disc recording / reproducing method capable of accurately executing switching between land tracking and groove tracking. .
[0006]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, an optical disc recording / reproducing apparatus of the present invention is configured as follows.
(1) According to the present invention,
A spiral land track and a groove track formed by the land portion and the groove portion, each having a predetermined track length, and a header data area in which header data is recorded and a user data area in which user data is recorded In an optical disc recording / reproducing apparatus for recording data on an optical disc in which a format having a plurality of continuous sector areas is defined or reproducing the recorded data,
Reproducing means for reproducing data recorded on the optical disc;
From the characteristics of the reproduced signal reproduced by the reproducing means, first identifying means for identifying which sector area of the land track or the groove track corresponds to the sector area to be reproduced;
First tracking control means for controlling tracking according to the identification result by the first identification means;
Sector area having the header data from the data reproduced by the reproducing means and identifying data that can identify the sector area corresponding to either the land track or the groove track included in the header data A second identification means for identifying which of the land track and the groove track the sector area corresponds to;
Second tracking control means for controlling tracking according to the identification result by the second identification means;
An optical disc recording / reproducing apparatus characterized by comprising:
[0007]
(2) According to the present invention,
A spiral land track and a groove track formed by the land portion and the groove portion, each having a predetermined track length, and a header data area in which header data is recorded and a user data area in which user data is recorded In an optical disc recording / reproducing apparatus for recording data on an optical disc in which a format having a plurality of continuous sector areas is defined or reproducing the recorded data,
Reproducing means for reproducing data recorded on the optical disc;
From the characteristics of the reproduced signal reproduced by the reproducing means, first identifying means for identifying which sector area of the land track or the groove track corresponds to the sector area to be reproduced;
First tracking control means for switching and controlling land tracking corresponding to the land track and groove tracking corresponding to the groove track in accordance with the identification result by the first identifying means;
It is data reproduced by the reproducing means, and the sector area having these ID data as header data is located on either the land track or the groove track from the relationship of a plurality of ID data included in the header data. A second identification means for identifying the sector area,
A second tracking control means for switching between land tracking corresponding to the land track and groove tracking corresponding to the groove track in accordance with an identification result by the second identifying means;
An optical disc recording / reproducing apparatus characterized by comprising:
[0008]
(3) According to the present invention,
A spiral land track and a groove track formed by the land portion and the groove portion, each having a predetermined track length, and a header data area in which header data is recorded and a user data area in which user data is recorded In an optical disc recording / reproducing apparatus for recording data on an optical disc in which a format having a plurality of continuous sector areas is defined or reproducing the recorded data,
Reproducing means for reproducing data recorded on the optical disc;
From the characteristics of the reproduced signal reproduced by the reproducing means, first identifying means for identifying which sector area of the land track or the groove track corresponds to the sector area to be reproduced;
First tracking control means for switching and controlling land tracking corresponding to the land track and groove tracking corresponding to the groove track in accordance with the identification result by the first identifying means;
The data reproduced by the reproducing means, and when the first and second ID numbers included in the header data have a first ID number> a second ID number, the ID numbers are A sector area having header data is identified as a sector area corresponding to the land track, and when first ID number <second ID number, a sector area having these ID numbers as header data corresponds to the groove track. A second identification means for identifying the sector area;
A second tracking control means for switching between land tracking corresponding to the land track and groove tracking corresponding to the groove track in accordance with an identification result by the second identifying means;
An optical disc recording / reproducing apparatus characterized by comprising:
[0009]
As a result of taking the above-mentioned means, the following operation occurs.
In the optical disk recording / reproducing apparatus of the present invention, the first discriminating whether the sector area to be reproduced is the sector area corresponding to the land track or the groove track from the feature of the reproduced signal reproduced. From the identification means and the identification data that can identify which of the land track and groove track included in the header data, the sector area having this header data is either the land track or the groove track. Since the second identification means for identifying the sector area corresponding to is provided, the sector area corresponding to the land track or the groove track can be identified from the characteristics of the reproduction signal and the identification data. Furthermore, since the first and second tracking control means for controlling tracking according to the identification results by the first and second identification means are provided, tracking control based on the characteristics of the reproduction signal and the identification data is possible. Become.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an optical disc apparatus according to an embodiment of the present invention. This optical disc apparatus records data on an optical disc (DVD-RAM) 1 as an information recording medium using focused light or reproduces recorded data.
[0011]
The optical disc 1 is formed by, for example, forming a circular film of glass or plastics on a surface of a substrate formed of a metal film layer such as tellurium or bismuth in a donut shape, and forming concentric or spiral grooves (recesses) and Phase change type in which data is recorded using both lands (projections) or recorded data is reproduced, and header data (address data, etc.) is recorded at predetermined intervals by a recording mark in the mastering process It is a rewritable disc.
[0012]
As shown in FIGS. 2 and 3, the optical disc 1 includes a lead-in area 2, a data area 3, a lead-out area 4, and the like. The lead-in area 2 includes an embossed data zone 5 composed of a plurality of tracks and a rewritable data zone 6 composed of a plurality of tracks. In the emboss data zone 5, reference signals and control data are recorded at the time of manufacture. The rewritable data zone 6 includes a guard track zone, a disk test zone, a drive test zone, a disk identification data zone, and a replacement management zone as a replacement management area. The data area 3 is composed of a plurality of, for example, 24 zones 3a,. The lead-out area 4 is composed of a plurality of tracks, and is a rewritable data zone similar to the rewritable data zone 6 so that the same recording contents as the data zone 6 can be recorded.
[0013]
As shown in FIG. 2 and FIG. 3, the optical disc 1 includes a data zone 6 that can be rewritten with an embossed data zone 5 in the lead-in area 2, a zone 3a in the data area 3,. It consists of four data zones, and the clock signal for each zone is the same, and the rotational speed (speed) of the optical disc 1 for each zone and the number of sectors for each track are different.
[0014]
In the zones 3a,..., 3x of the data area 3, the rotation speed (speed) decreases and the number of sectors per track increases as it goes from the inner circumference side to the outer circumference side of the optical disc 1. The relationship between the speed data (the number of revolutions) and the number of sectors per track for each of the zones 3a,... 3x, 4, 5, 6 is recorded in a table 10a of the memory 10 described later as shown in FIG. .
[0015]
As shown in FIGS. 2 and 3, the tracks of the zones 3a,..., 3x of the data area 3 are previously stored in units of ECC (error correction code) block data units (for example, 38688 bytes) as data recording units. Data is recorded. As shown in FIG. 2, a header field 11 in which header data such as an address is recorded for each sector is pre-formatted on the tracks of the zones 3a,... 3x of the data area 3 in advance.
[0016]
Here, it returns to description of FIG. 1 again. As shown in FIG. 1, the optical disk 1 is rotated by a motor 23 at, for example, a different number of rotations for each zone. The motor 23 is controlled by a motor control circuit 24.
[0017]
Recording of data on the optical disc 1 or reproduction of data recorded on the optical disc 1 is performed by an optical head 25 as reproduction means. The optical head 25 is fixed to a drive coil 27 that constitutes a movable part of the linear motor 26, and the drive coil 27 is connected to a linear motor control circuit 28.
[0018]
A speed detector 29 is connected to the linear motor control circuit 28, and a speed signal of the optical head 25 is sent to the linear motor control circuit 28.
In addition, a permanent magnet (not shown) is provided in the fixed portion of the linear motor 26, and the optical head 25 moves in the radial direction of the optical disk 1 when the drive coil 27 is excited by the linear motor control circuit 28. It has come to be.
[0019]
An objective lens 30 is supported on the optical head 25 by a wire or a leaf spring (not shown). The objective lens 30 is moved by the drive coil 31 in the focusing direction (the optical axis direction of the lens) and is driven by the drive coil 32. It can be moved in the tracking direction (direction perpendicular to the optical axis of the lens).
[0020]
Further, the laser control circuit 33 drives the semiconductor laser oscillator 39 to generate laser light. The laser control circuit 33 corrects the amount of laser light emitted from the semiconductor laser oscillator 39 in accordance with the monitor current from the monitoring photodiode PD of the semiconductor laser oscillator 39.
[0021]
The laser control circuit 33 operates in synchronization with a recording clock signal from a PLL circuit (not shown). This PLL circuit divides a basic clock signal from an oscillator (not shown) to generate a recording clock signal.
[0022]
The laser light generated from the semiconductor laser oscillator 39 driven by the laser control circuit 33 is irradiated onto the optical disc 1 through the collimator lens 40, the half prism 41, and the objective lens 30, and the reflected light from the optical disc 1. Is guided to the photodetector 44 through the objective lens 30, the half prism 41, the condenser lens 42, and the cylindrical lens 43.
[0023]
The photodetector 44 is composed of four divided photodetector cells 44a, 44b, 44c and 44d.
The output signal of the light detection cell 44a of the light detector 44 is supplied to one end of the adder 46a via the amplifier 45a, and the output signal of the light detection cell 44b is supplied to one end of the adder 46b via the amplifier 45b. The output signal of the photodetection cell 44c is supplied to the other end of the adder 46a via the amplifier 45c, and the output signal of the photodetection cell 44d is supplied to the other end of the adder 46b via the amplifier 45d. It is like that.
[0024]
The output signal of the photodetector cell 44a of the photodetector 44 is supplied to one end of the adder 46c via the amplifier 45a, and the output signal of the photodetector cell 44b is supplied to one end of the adder 46d via the amplifier 45b. The output signal of the photodetection cell 44c is supplied to the other end of the adder 46d via the amplifier 45c, and the output signal of the photodetection cell 44d is supplied to the other end of the adder 46c via the amplifier 45d. It is like that.
[0025]
The output signal of the adder 46a is supplied to the inverting input terminal of the differential amplifier OP2, and the output signal of the adder 46b is supplied to the non-inverting input terminal of the differential amplifier OP2. As a result, the differential amplifier OP2 supplies a signal related to the focus point (focus error signal) to the focusing control circuit 47 in accordance with the difference between the adders 46a and 46b. The output signal of the focusing control circuit 47 is supplied to the drive coil 31 and controlled so that the laser beam is always in the just focus on the optical disc 1.
[0026]
The output signal of the adder 46c is supplied to the inverting input terminal of the differential amplifier OP1, and the output signal of the adder 46d is supplied to the non-inverting input terminal of the differential amplifier OP1. Thus, the differential amplifier OP1 supplies a tracking error signal to the tracking control circuit 48 and the header position detection circuit 60 as tracking control means according to the difference between the adders 46c and 46d. The tracking control circuit 48 creates a track drive signal in accordance with the tracking error signal supplied from the differential amplifier OP1. The header position detection circuit 60 detects the position of the header. Various signals output from the header position detection circuit 60 are supplied to the land / groove switching point detection circuit 70. The land / groove switching point detection circuit 70 detects a switching point between a land and a groove.
[0027]
The track drive signal output from the tracking control circuit 48 is supplied to the drive coil 32 in the tracking direction. The tracking error signal used in the tracking control circuit 48 is supplied to the linear motor control circuit 28.
[0028]
A signal obtained by adding the output signals from the adders 46c and 46d by the adder 46e, that is, the sum signal of the outputs of the photodetection cells 44a to 44d of the photodetector 44 in the state in which focusing and tracking are performed as described above. Reflects the change in reflectance from the pits (recording data) formed on the track. This signal is supplied to the data reproduction circuit 38, and the data reproduction circuit 38 reproduces the recorded data.
[0029]
The reproduction data reproduced by the data reproduction circuit 38 is subjected to error correction by the error correction circuit 52 using the assigned error correction code ECC, and then the optical disk control device 56 as an external device via the interface circuit 55. Is output.
[0030]
When the objective lens 30 is moved by the tracking control circuit 48, the linear motor control circuit 28 moves the linear motor 26, that is, the optical head 25 so that the objective lens 30 is positioned near the center position in the optical head 25. It is supposed to move.
[0031]
In addition, a data generation circuit 34 is provided in front of the laser control circuit 33. The data generation circuit 34 converts ECC block format data as recording data supplied from the error correction circuit 52 into recording ECC block format data to which a synchronization code for ECC block is added. A generation circuit 34a and a modulation circuit 34b for modulating the recording data from the ECC block data generation circuit 34a by the 8-16 code conversion method are provided.
[0032]
The data generation circuit 34 is supplied with record data to which an error correction code is given by the error correction circuit 52 and dummy data for error check read from the memory 10. The error correction circuit 52 is supplied with recording data from an optical disk control device 56 as an external device via an interface circuit 55 and a bus 49.
[0033]
The error correction circuit 52 assigns error correction codes (ECC1, ECC2) in the horizontal direction and the vertical direction to the recording data in units of sectors for every 4 Kbytes to the recording data of 32 Kbytes supplied from the optical disk control device 56. Sector ID (logical address number) is assigned to generate ECC block format data.
[0034]
Further, in this optical disc apparatus, a D / A converter used for transferring information between the focusing control circuit 47, the tracking control circuit 48, the linear motor control circuit 8 and the CPU 50 for controlling the entire optical disc apparatus. 51 is provided.
[0035]
The motor control circuit 24, the linear motor control circuit 28, the laser control circuit 33, the data reproduction circuit 38, the focusing control circuit 47, the tracking control circuit 48, the error correction circuit 53, etc. are controlled by the CPU 50 via the bus 49. The CPU 50 is configured to perform a predetermined operation according to a control program recorded in the memory 10.
[0036]
The memory 10 stores a control program or is used for data recording. The memory 10 has a table 10a in which the relationship between the speed data (number of rotations) and the number of sectors per track is recorded for each of the zones 3a,... 3x, 4, 5, and 6.
[0037]
Next, a method of detecting the switching between the land track and the groove track in an analog manner and switching between the land tracking and the groove tracking (analog tracking control method) will be briefly described.
[0038]
This analog tracking control is performed by the header position detection circuit 60, the land / groove switching point detection circuit 70, and the tracking control circuit 48. The header position detection circuit 60 detects a header position (outer header and inner header) based on the track error signal supplied from the differential amplifier OP1, and outputs a header detection signal, an outer header detection signal, and an inner header detection signal. To do. The land / groove switching point detection circuit 70 detects a land / groove switching point based on the header detection signal, the outer header detection signal, and the inner header detection signal supplied from the header position detection circuit 60. A switching signal is output. The tracking control circuit 48 switches between land tracking and groove tracking based on the land / groove switching signal supplied from the land / groove switching point detection circuit 70.
[0039]
Here, the header position detection circuit 60 and the land / groove switching point detection circuit 70 will be described with reference to FIGS.
As shown in FIG. 12, the header position detection circuit 60 includes a low-pass filter (LPF) 61, a high-pass filter (HPF) 62, a slice level generation unit 63, a differential amplifier 64, an MM 65, an AND circuit 66, an OR circuit 67, and the like. It is comprised by. The header position detection circuit 60 receives a track error signal supplied from the differential amplifier OP1, and the header position detection circuit 60 outputs a header detection signal, an inner header detection signal, and an outer header detection signal. FIG. 13 shows the relationship among these track error signal, header detection signal, inner header detection signal, and outer header detection signal.
[0040]
As shown in FIG. 14, the land / groove switching point detection circuit 70 includes a flip-flop circuit 71, an AND circuit 72, a NAND circuit 73, an OR circuit 74, a NOR circuit 75, an EXOR circuit 76, and the like. . The land / groove switching point detection circuit 70 includes a header detection signal, an inner header detection signal, an outer header detection signal, a clock signal (CLK / 8) and a clock signal (CLK / 256) supplied from the header position detection circuit 60. ) And the land / groove switching point detection circuit 70 outputs a land / groove switching signal. FIG. 15 shows the relationship among these header detection signals, inner header detection signals, outer header detection signals, and land / groove switching signals. FIG. 15 also shows various signals (S1 to S7) generated in the process of generating the land / groove switching signal from the header detection signal, the inner header detection signal, and the outer header detection signal.
[0041]
Next, the sector format will be described with reference to FIG. FIG. 5 is a diagram schematically showing the format of one sector and the format of the header field.
[0042]
As shown in FIG. 5, one sector is composed of approximately 2697 bytes, and is composed of a 128-byte header field 11, a 2-byte mirror field, and a 2567-byte recording field. The channel bits recorded in the sector are in the form of 8-16 code modulation of 8 bits of data into 16 bits of channel bits.
[0043]
The header field 11 is an area where predetermined data is recorded when the optical disc 1 is manufactured. The header field 11 includes four fields, that is, a header 1 field, a header 2 field, a header 3 field, and a header 4 field. The header 1 field and the header 3 field are 46 bytes, the header 2 field and the header 4 field are 18 bytes, a 36-byte or 8-byte synchronization code portion VFO (Variable Frequency Oscillator), a 3-byte address mark AM (Address Mark), a 4-byte address part PID (Position Identifier), a 2-byte error detection code IED (ID Error Detection Code), and a 1-byte postamble PA (Post Ambles).
[0044]
The header 1 field and the header 3 field have a 36-byte synchronization code portion VFO1, and the header field 2 and the header 4 field have an 8-byte synchronization code portion VFO2. The synchronization code portions VFO1 and VFO2 are areas for pulling in the PLL, and the synchronization code portion VFO1 records “010...” In the channel bits for “36” bytes (channel bits of 646 bits) (fixed intervals). The synchronization code portion VFO2 is a recording of “8” bytes (128 bits of channel bits) of continuous “010...” In channel bits.
[0045]
The address mark AM is a “3” byte synchronization code indicating where the sector address starts. As a pattern of each byte of the address mark AM, a special pattern that does not appear in the data portion “0100100000000100” is used.
[0046]
PID1 to PID4 are areas in which sector information (including a PID number) consisting of 4 bytes and a sector number are recorded. This PID will be described in detail later.
[0047]
The error detection code IED is an error (error) detection code for a sector address (including an ID number), and can detect the presence or absence of an error in the read PID.
[0048]
The postamble PA (PA1, PA2) includes state information necessary for demodulation, and also has a role of polarity adjustment so that the header field 11 ends with a space.
[0049]
The mirror field is used for offset correction of a tracking error signal, timing generation of a land / groove switching signal, and the like.
The recording field includes a 10-26 byte gap field, a 20-26 guard 1 field, a 35-byte VFO3 field, a 3-byte PS (pre-synchronous code) field, a 2418-byte data field, and a 1-byte postamble 3 (PA3) field, guard 2 field of 48 to 55 bytes, and buffer field of 9 to 25 bytes.
[0050]
The gap field is an area where nothing is recorded.
The guard 1 field is an area provided in order to prevent the terminal degradation at the time of repeated recording unique to the phase change recording medium from reaching the VFO3 area.
[0051]
The VFO3 field is also an area for PLL lock, but it is also an area intended to synchronize byte boundaries by inserting a synchronization code into the same pattern.
The PS field is a tuning area for connecting to the data area.
[0052]
The data field is an area composed of a data ID, a data ID error correction code IED (Data ID Error Detection Code), a synchronization code, an ECC (Error Collection Code), an EDC (Error Detection Code), user data, and the like. The data ID is sector ID1 to ID16 having a 4-byte (32 channel bit) configuration of each sector. The data ID error correction code IED is an error correction code having a 2-byte (16 bits) configuration for data ID.
[0053]
A PA (post Amble) 3 field includes state information necessary for demodulation, and is an area indicating the end of the last byte of the previous data area.
The guard 2 field is an area provided in order to prevent the terminal degradation at the time of repeated recording unique to the phase change recording medium from reaching the data area.
[0054]
The buffer field is an area provided to absorb rotational fluctuations of a motor that rotates the optical disc 1 so that the data area does not cover the next header field 11.
[0055]
Subsequently, PIDs (PID1 to PID4) in the header field will be specifically described. The PID is composed of a 1-byte (8-bit) sector information field and a 3-byte (24-bit) sector number field (a logical sector number as a logical address indicating a logical position on a track).
[0056]
Further, this sector information is composed of a 2-bit reserve field, a 2-bit PID number field, a 3-bit sector type field, and a 1-bit layer number field.
[0057]
In this embodiment, nothing is recorded in the reserved field.
A PID number is recorded in the PID number field. For example, “00” indicating PID1 is indicated in the PID number field in the header 1 fee field, “01” is indicated in the PID number field in the header 2 fee field, and PID3 is indicated in the PID number field in the header 3 fee field. “10” indicating “ID” and “11” indicating PID4 are recorded in the PID number field in the header 4 field.
[0058]
In the present invention, land tracking and groove tracking are switched based on the relationship between the PID numbers recorded in the PID number field in the header 1 field to the header 4 field. Switching between land tracking and groove tracking using the PID number is called a tracking control method using the PID number, and will be described in detail later.
[0059]
In the sector type field, “000” indicating a read-only sector, “001”, “010”, or “011” indicating a reserved sector (Reserved), a land or groove track “100” indicating the rewritable first sector, “101” indicating the rewritable last sector of the land or groove track, and rewriting of the land or groove track “110” indicating that it is a sector immediately before the last possible sector (Rewritable before last sector), and “111” indicating that it is a rewritable other sector of the land or groove track. To be recorded.
[0060]
In the present invention, land tracking and groove tracking can be switched based on the sector type recorded in the sector type field. This switching between land tracking and groove tracking by sector type is called a tracking control method by sector type and will be described in detail later.
[0061]
In the layer number field, “1” or “0” indicating layer 1 or 0 is recorded.
Next, a tracking control method based on PID numbers will be described with reference to FIGS.
[0062]
First, a tracking control method based on the PID number of the header field 11 provided between the groove sector and the groove sector or between the land sector and the land sector will be described with reference to FIGS.
[0063]
The header field 11 is composed of a plurality of pits P as shown in FIG. The centers of the pits constituting the headers H12-1 and H12-2 are located on the same line as the tangent line between the land sector L02 and the groove sector G12 (or the land sector L01 and the groove sector G11). The centers of the pits constituting the header H22-3 and the header H22-4 are located on the same line as the tangent line of the groove sector G12 and the land sector L22 (or the groove sector G11 and the land sector L21). The centers of the pits constituting the header H32-1 and the header H32-2 are located on the same line as the tangent line between the land sector L22 and the groove sector G32 (or the land sector L21 and the groove sector G31). The centers of the pits constituting the header H42-3 and the header H42-4 are located on the same line as the tangent line of the groove sector G32 and the land sector L42 (or the groove sector G31 and the land sector L41). The centers of the pits constituting the header H52-1 and the header H52-2 are located on the same line as the tangent line between the land sector L42 and the groove sector G52 (or the land sector L41 and the groove sector G51). The centers of the pits constituting the header H62-3 and the header H62-4 are located on the same line as the tangent line of the groove sector G52 and the land sector L62 (or the groove sector G51 and the land sector L61).
[0064]
Also, the PID (physical ID number) number of each header of the header field 11 provided between the groove sectors has a relationship as shown in FIG. For example, description will be made by taking the PID number of each header provided between the groove sector G11 and the groove sector G12 as an example. Between the groove sector G11 and the groove sector G12, a header H12-1 (header 1 field), a header H12-2 (header 2 field), a header H22-3 (header 3 field), and a header H22-4 (header 4) Field). Also, the PID number of the header H12-1 is (n + 3N), the PID number of the header H12-2 is (n + 3N), the PID number of the header H22-3 is (n + 2N), and the PID number of the header H22-4 is (n + 2N). is there. That is, when the PID of each header provided between the groove sector and the groove sector is compared, the relationship of (PID number of header 1 field or header 2 field)> (PID number of header 3 field or header 4 field) is established. To do.
[0065]
On the other hand, the PID number of each header in the header field 11 provided between the land sectors has a relationship as shown in FIG. For example, description will be made by taking the PID number of each header provided between the land sector L21 and the land sector L22 as an example. Between land sector L21 and land sector L22, header H32-1 (header 1 field), header H32-2 (header 2 field), header H22-3 (header 3 field), and header H22-4 (header 4) Field). The PID number of the header H32-1 is (n + N), the PID number of the header H32-2 is (n + N), the PID number of the header H22-3 is (n + 2N), and the PID number of the header H22-4 is (n + 2N). is there. That is, when the PID of each header provided between the land sector and the land sector is compared, the relationship of (PID number of header 1 field or header 2 field) <(PID number of header 3 field or header 4 field) is established. To do.
[0066]
That is, if the relationship of (PID number of header 1 field or header 2 field)> (PID number of header 3 field or header 4 field) is found by header reproduction, the sector after this header is a groove sector. And reproduction processing corresponding to the groove sector can be performed. On the contrary, if the relationship of (PID number of header 1 field or header 2 field) <(PID number of header 3 field or header 4 field) is found by header reproduction, the sector after this header is a land sector. Thus, the reproduction process corresponding to the land sector can be performed.
[0067]
Note that the land sector and the groove sector are identified by the CPU 50 as an identification unit. Further, it is assumed that reproduction processing according to the identification result, that is, land tracking according to the land track, and groove tracking according to the groove sector are performed by a tracking control circuit as tracking control means.
[0068]
Next, a tracking control method based on the PID number of the header field 11 provided between the groove sector and the land sector, that is, at the change of the groove and land will be described with reference to FIGS.
[0069]
The header field 11 is composed of a plurality of pits P as shown in FIG. The centers of the pits constituting the header H20-3 and the header H20-4 are located on the same line as the tangent line between the groove sector G10 and the land sector L20. The centers of the pits constituting the headers H30-1 and H30-2 are located on the same line as the tangent line between the land sector L20 and the groove sector G30 (or the groove sector G1n and the land sector L2n). The centers of the pits constituting the header H40-3 and the header H40-4 are located on the same line as the tangent line between the groove sector G30 and the land sector L40 (or the land sector L2n and the groove sector G3n). The centers of the pits constituting the header H50-1 and the header H50-2 are located on the same line as the tangent line between the land sector L40 and the groove sector G50 (or the groove sector G3n and the land sector L4n). The centers of the pits constituting the header H60-3 and the header H60-4 are located on the same line as the tangent line of the groove sector G50 and the land sector L60 (or the land sector L4n and the groove sector G5n). The centers of the pits constituting the header H70-1 and the header H70-2 are located on the same line as the tangent line between the land sector L60 and the groove sector G70.
[0070]
Also, the PID (physical ID number) number of each header of the header field 11 provided between the land sector and the groove sector (when changing from the land sector to the groove sector) has a relationship as shown in FIG. For example, description will be made by taking as an example the PID number of each header provided between the land sector L2n and the groove sector G30. Between the land sector L2n and the groove sector G30, a header H30-1 (header 1 field), a header H30-2 (header 2 field), a header H40-3 (header 3 field), and a header H40-4 (header 4) Field). The header H30-1 has a PID number (m + 3N), the header H30-2 has a PID number (m + 3N), the header H40-3 has a PID number (m + 2N), and the header H40-4 has a PID number (m + 2N). is there. That is, when the PID of each header provided between the land sector and the groove sector is compared, the relationship of (PID number of header 1 field or header 2 field)> (PID number of header 3 field or header 4 field) is established. To do.
[0071]
On the other hand, the PID number of each header in the header field 11 provided between the groove sector and the land sector (when changing from the groove sector to the land sector) has a relationship as shown in FIG. For example, description will be made by taking the PID number of each header provided between the groove sector G3n and the land sector L40 as an example. Between the groove sector G3n and the land sector L40, a header H50-1 (header 1 field), a header H50-2 (header 2 field), a header H40-3 (header 3 field), and a header H40-4 (header 4) Field). The header H50-1 PID number is (m + N), the header H50-2 PID number is (m + N), the header H40-3 PID number is (m + 2N), and the header H40-4 PID number is (m + 2N). is there. That is, when the PID of each header provided between the groove sector and the land sector is compared, the relationship of (PID number of header 1 field or header 2 field) <(PID number of header 3 field or header 4 field) is established. To do.
[0072]
That is, if the relationship of (PID number of header 1 field or header 2 field)> (PID number of header 3 field or header 4 field) is found by header reproduction, the sector after this header is a groove sector. And reproduction processing corresponding to the groove sector can be performed. On the contrary, if the relationship of (PID number of header 1 field or header 2 field) <(PID number of header 3 field or header 4 field) is found by header reproduction, the sector after this header is a land sector. Thus, the reproduction process corresponding to the land sector can be performed.
[0073]
Note that the land sector and the groove sector are identified by the CPU 50 as an identification unit. Further, it is assumed that reproduction processing according to the identification result, that is, land tracking according to the land track, and groove tracking according to the groove sector are performed by a tracking control circuit as tracking control means.
[0074]
As described above with reference to FIGS. 6 to 9, the subsequent sector is a land sector because of the size relationship between the header 1 field (or header 2 field) and the header 3 field (or header 4 field) obtained by header reproduction. Or a groove sector can be identified. Based on this identification result, the drive coil 32 is driven by the track drive signal output from the tracking control circuit 28, and land tracking and groove tracking are switched.
[0075]
Next, a tracking control method by sector type will be described with reference to FIG.
As shown in FIG. 10, sector type information is recorded in each sector in one track (land track or groove track) as described above. That is, the first sector of the track is the “first sector”, the last sector of the track is the “last sector”, the sector immediately before the last sector of the track is “the last sector”, the first sector of the track and the track In the sector between the sector immediately before the last sector, “other sector” is recorded as sector type information.
[0076]
Therefore, the track change can be detected based on the sector type information recorded in the sectors before and after the change between the tracks, that is, the land track and the groove track. For example, if it is found from the reproduced sector type information that this sector is the last sector, it can be detected that the track is switched after the next sector. If it is found from the reproduced sector type information that this sector is the last sector, it can be detected that the track is switched in the next sector. Furthermore, if it is determined from the reproduced sector type information that this sector is the first sector, it can be detected that the track has been switched. These detections are performed by the CPU 50 as detection means. Further, it is assumed that reproduction processing according to the detection result, that is, land tracking according to the land track, and groove tracking according to the groove sector are performed by a tracking control circuit as tracking control means.
[0077]
In the present invention, switching from a land track to a groove track or from a groove track to a land track can be detected based on the sector type recorded in the sector type field. Based on the detection result, the drive coil 32 is driven by the track drive signal output from the tracking control circuit 28 to switch between land tracking and groove tracking.
[0078]
Next, tracking control using an analog tracking control method, a tracking control method based on a PID number, and a tracking control method based on a sector type will be described with reference to the flowchart of FIG.
[0079]
As shown in FIG. 11, the processing proceeds in the order of seek operation (ST10) and track-on (ST12), and the analog tracking control described above is executed (ST14).
[0080]
Subsequently, header playback is performed (ST16), and when the header is normally played back (ST18, YES), tracking control based on the PID number described above is executed (ST20). The tracking control based on the PID number can be executed if at least one of PID1 and PID2 and at least one of PID3 and PID4 can be reproduced. This is because in tracking control using this PID number, the magnitude relationship between PID1 or PID2 and PID3 or PID4 is the point of control. When tracking control by the PID number is normally executed (ST22, YES), the tracking control ends.
[0081]
When the tracking control by the PID number is not normally executed (ST22, NO) and at least one PID is reproduced (ST24, YES), information on the sector type included in the reproduced PID The tracking control based on the sector type described above is executed (ST26).
[0082]
When the tracking control by the PID number is not normally executed (ST22, NO) and the PID cannot be reproduced (ST24, NO), that is, when the sector type of the current sector cannot be reproduced, The current sector type is predicted from the sector type information of this sector (ST28), and tracking control is performed based on the prediction result. That is, if the previous sector is the last sector, the current sector is predicted to be the first sector, and switching from land tracking to groove tracking or from groove tracking to land tracking is performed (ST30). When the sector type of the current sector and the sector type of the previous sector are unknown, the current sector type is predicted from the sector type information of the previous sector.
[0083]
【The invention's effect】
According to the present invention, it is possible to provide an optical disc recording / reproducing apparatus and an optical disc recording / reproducing method capable of accurately executing switching between land tracking and groove tracking.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an optical disc apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view showing a schematic configuration of an optical disc.
FIG. 3 is a block diagram showing a schematic configuration of an optical disc.
FIG. 4 is a diagram for explaining the number of rotations and the number of sectors per track in each zone of the optical disc.
FIG. 5 shows a layout of a sector field, a header field, a PID field, and a sector information layout.
FIG. 6 is a diagram schematically showing a header field provided between a groove sector and a groove sector, or between a land sector and a land sector.
FIG. 7 is a diagram schematically showing a header field provided between a groove sector and a groove sector, or between a land sector and a land sector.
FIG. 8 is a diagram schematically showing a header field provided between a groove sector and a land sector.
FIG. 9 is a diagram schematically showing a header field provided between a groove sector and a land sector.
FIG. 10 is a diagram for explaining tracking control by sector type.
FIG. 11 is a flowchart for explaining tracking control using analog tracking control, tracking control by PID number, and tracking control by sector type.
FIG. 12 is a diagram showing a schematic configuration of a header position detection circuit.
FIG. 13 is a diagram showing a relationship among a track error signal, a header detection signal, an inner header detection signal, and an outer header detection signal.
FIG. 14 is a diagram showing a schematic configuration of a land / groove switching point detection circuit;
FIG. 15 is a diagram illustrating a relationship among a header detection signal, an inner header detection signal, an outer header detection signal, and a land / groove switching signal.
[Explanation of symbols]
1 ... Optical disc
10 ... Memory
25. Optical head
31, 32 ... Driving coil
33 ... Laser control circuit
38. Data reproduction circuit
48 ... Tracking control circuit
50 ... CPU

Claims (4)

  An optical disc composed of a plurality of concentric zones,
  Each zone has a spiral track formed by land tracks and groove tracks,
  Each of the land track and the groove track has a plurality of sector regions,
  The number of the sector areas included in the land track or the groove track in the same zone is the same, the number of the sector areas included in the land track or the groove track in a different zone is different,
  The sector area includes a header data area in which header data is recorded and a user data area in which user data is recorded,
  The header data area includes a sector type field and a sector number field,
  The sector number field includes an address,
  The sector type field of the sector area located at the end of the land track and the groove track includes data indicating the last sector in one track.
  An optical disc characterized by the above.   An optical disk composed of a plurality of concentric zones, each zone having a spiral track formed by a land track and a groove track, each of the land track and the groove track having a plurality of sector regions. The land track or the groove track in the same zone has the same number of sector regions, the land track in the different zone or the groove track has a different number of sector regions, the sector region, A header data area in which header data is recorded; and a user data area in which user data is recorded.The header data area includes a sector type field and a sector number field.The sector number field includes an address. Land track and It said sector type field of the sector area which is located in the final of the groove track includes data indicating that the last sector in one track, the optical disk reproducing apparatus for reproducing information from the optical disk,
  Reproducing means for reproducing data recorded on the optical disc;
  Identification for identifying whether the sector area having the header data corresponds to the last sector in one track based on the data of the sector type field included in the header data, which is data reproduced by the reproducing means Means,
  Tracking control means for controlling tracking based on the identification result by the identification means;
  An optical disc reproducing apparatus comprising:   An optical disk composed of a plurality of concentric zones, each zone having a spiral track formed by a land track and a groove track, each of the land track and the groove track having a plurality of sector regions. The land track or the groove track in the same zone has the same number of sector regions, the land track in the different zone or the groove track has a different number of sector regions, the sector region, A header data area in which header data is recorded; and a user data area in which user data is recorded.The header data area includes a sector type field and a sector number field.The sector number field includes an address. Land track and It said sector type field of the sector area which is located in the final of the groove track includes data indicating that the last sector in one track, the optical disk reproducing method for reproducing information from the optical disk,
  Play back the data recorded on the optical disc,
  Identifying whether the sector area having the header data corresponds to the last sector in one track based on the data of the sector type field included in the header data, the reproduced data.
  Based on the identification result, tracking is controlled.
  An optical disc reproducing method characterized by the above.   An optical disk composed of a plurality of concentric zones, each zone having a spiral track formed by a land track and a groove track, each of the land track and the groove track having a plurality of sector regions. The land track or the groove track in the same zone has the same number of sector regions, the land track in the different zone or the groove track has a different number of sector regions, the sector region, A header data area in which header data is recorded; and a user data area in which user data is recorded.The header data area includes a sector type field and a sector number field.The sector number field includes an address. Land track and It said sector type field of the sector area which is located in the final of the groove track includes data indicating that the last sector in one track, the optical disk recording method for recording information on this optical disk,
  Play back the data recorded on the optical disc,
  Identifying whether the sector area having the header data corresponds to the last sector in one track based on the data of the sector type field included in the header data, the reproduced data.
  Based on the identification result, tracking is controlled.
  An optical disc recording method.

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