JP3693545B2 - Optical disc media - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk medium and a reproducing method thereof , and more specifically, signals are supplied to both a concave recording track formed by a guide groove on the disk and a convex recording track formed between the guide grooves. The present invention relates to an optical disc medium for recording the above and a reproducing method thereof .
[0002]
[Prior art]
In recent years, as a recording method for a large-capacity rewritable optical disk medium, data is recorded in both the groove portion (also referred to as groove: G) and the groove portion (also referred to as land: L) in order to improve the recording density. A so-called land / groove recording system is being studied. Since the track pitch can be halved with the same groove pitch disk, the effect of increasing the density is great. As described above, the groove portion and the inter-groove portion may be referred to as a concave portion and a convex portion, respectively, as described above.
[0003]
First, a conventional land / groove recording type optical disc apparatus will be described. FIG. 9 is a block diagram showing a configuration of a conventional optical disc apparatus described in Japanese Patent Laid-Open No. 6-176404. In FIG. 9, 100 is an optical disk, 101 is a semiconductor laser, 102 is a collimating lens that converts laser light from the semiconductor laser 101 into parallel light, 103 is a half mirror, and 104 is a light beam that condenses parallel light that has passed through the half mirror 103 on the optical disk. An objective lens 105 is a photodetector that receives reflected light from the optical disc 100 that has passed through the objective lens 104 and the half mirror 103, and is divided into two in parallel with the track direction of the disc to obtain a tracking error signal. It consists of two light receiving parts. Reference numeral 106 denotes an actuator that supports the objective lens 104. A portion 107 surrounded by a dotted line is attached to the head base, and constitutes an optical head. 108 is a differential amplifier to which a detection signal output from the photodetector 105 is input, 109 is a tracking error signal from the differential amplifier 108, and a control signal T1 is input from a system control unit, which will be described later, to the tracking control unit 110. A polarity inversion unit that outputs a tracking error signal. Here, regarding the polarity of the tracking control, when the tracking error signal is input from the differential amplifier 108 to the tracking control unit 110 with the same polarity, tracking pull-in is performed on the recording track of the groove. A tracking control unit 110 receives an output signal from the polarity inversion unit 109 and a control signal T2 from a system control unit 121 (to be described later) and outputs a tracking control signal to the driving unit 120 and the traverse control unit 116 (to be described later). Reference numeral 111 denotes an addition amplifier that receives a detection signal output from the photodetector 105 and outputs a sum signal. Reference numeral 112 denotes a high-frequency component input from the addition amplifier 111, and a digital signal is input to a reproduction signal processing unit 113 and an address reproduction unit 114 described later. The waveform shaping unit 113 outputs a reproduction data to an output terminal. Reference numeral 114 denotes a digital signal input from the waveform shaping unit, and an address reproduction unit that outputs an address signal to an address calculation unit 115 described later. Reference numeral 115 denotes an address signal from the address reproduction unit 114 and control signal T1 from the system control unit 121. The address calculation unit outputs an accurate address signal to the system control unit 121. Reference numeral 116 denotes a traverse control unit that outputs a drive current to a traverse motor 117 described later in response to a control signal T3 from a system control unit 121 described later. Reference numeral 117 denotes a traverse motor that moves the optical head 107 in the radial direction of the optical disc 100. A recording signal processing unit 118 receives recording data and outputs a recording signal to a laser (LD) driving unit 119, which will be described later. 119 receives a control signal T4 from a system control unit 121, which is described later, and a recording signal from a recording signal processing unit 118. Is a laser drive unit that inputs a drive current to the semiconductor laser 101. A driving unit 120 outputs a driving current to the actuator 106. Reference numeral 121 denotes a control signal T1 to T4 output to the tracking control unit 110, traverse control unit 116, address calculation unit 115, polarity inversion unit 109, recording signal processing unit 118, and LD drive unit, and an address signal is input from the address calculation unit 115. System control unit.
[0004]
The operation of the conventional optical disc apparatus configured as described above will be described with reference to FIG. The laser beam output from the semiconductor laser 101 is collimated by the collimator lens 102 and converged on the optical disc 100 by the objective lens 104 through the beam splitter 103. The laser beam reflected by the optical disc 100 has information on the recording track, and is guided onto the photodetector 105 by the beam splitter 103 through the objective lens 104. The photodetector 105 converts the change in the light amount distribution of the incident light beam into an electrical signal, and outputs the electrical signal to the operation amplifier 108 and the addition amplifier 111, respectively. The differential amplifier 108 performs a current-voltage conversion (IV conversion) on each input current, takes a difference, and outputs it as a push-pull signal. The polarity inversion unit 109 recognizes whether the track being accessed is a land or a groove by the control signal T1 from the system control unit, and inverts the polarity only when the track is a land, for example. The tracking control unit 110 outputs a tracking control signal to the driving unit 120 according to the level of the input tracking error signal, and the driving unit 120 sends a driving current to the actuator 106 according to this signal to record the objective lens 104. Position control in the direction across the track. As a result, the light spot correctly scans the track. On the other hand, the addition amplifier 111 performs addition after current-voltage conversion (IV conversion) of the output current of the light receiving unit 105 and outputs the sum as a sum signal to the waveform shaping circuit 112. The waveform shaping circuit 112 data-slices the analog waveform data signal and the address signal with a certain threshold value to form a pulse waveform, and outputs the pulse waveform to the reproduction signal processing unit 113 and the address reproduction unit 114. The reproduction signal processing unit 113 demodulates the input digital data signal, and thereafter performs processing such as error correction and outputs it as reproduction data. The address reproducing unit 114 demodulates the input digital address signal and outputs it to the address calculating unit 115 as position information on the disk. The address calculation unit 115 calculates the address of the accessed sector from the address signal read from the optical disc 100 and the land / groove signal from the system control unit 121. The calculation method will be described later. Based on this address signal, the system control unit 121 determines whether the current light beam is at a desired address. The traverse control unit 116 outputs a drive current to the traverse motor 117 according to the control signal T3 from the system control unit 121 when the optical head is moved, and moves the optical head 107 to the target track. At this time, the tracking control unit 110 temporarily suspends the tracking servo by the control signal T2 from the system control unit 121. During normal reproduction, the traverse motor 117 is driven in accordance with the tracking error signal input from the tracking control unit 110, and the optical head 107 is gradually moved in the radial direction along with the progress of reproduction. The recording signal processing unit 118 adds an error correction code or the like to the recording data input at the time of recording, and outputs it to the LD driving unit 119 as an encoded recording signal. When the system control unit 121 sets the LD driving unit 119 to the recording mode by the control signal T4, the LD driving circuit 119 modulates the driving current applied to the semiconductor laser 101 according to the recording signal. As a result, the intensity of the light spot irradiated onto the optical disc 100 changes according to the recording signal, and a recording pit is formed. On the other hand, at the time of reproduction, the LD drive unit 119 is set to the reproduction mode by the control signal T4, and the drive current is controlled so that the semiconductor laser 101 emits light with a constant intensity. As a result, the recording pits and pre-pits on the recording track can be detected.
[0005]
Next, the single spiral land groove format will be described. In a conventional land / groove recording type optical disk, the groove portions are continuously connected on the disk, and therefore the inter-groove portions are also continuously connected on the disk. FIG. 10 is a diagram showing an optical disc having a format in which a recording track in a conventional groove portion and a recording track in the groove portion are alternately connected to form one recording spiral. As shown in FIG. 10, an optical disc having a format in which a recording track in a groove portion and a recording track in the groove portion are alternately connected to form one recording spiral is disclosed in Japanese Patent Laid-Open No. 4-38633. Yes. An optical disc having such a format is referred to herein as a single spiral / land groove format: SS-L / G format.
In order to apply tracking servo to an SS-L / G format disk, the connection point where the recording track of the groove portion and the recording track of the groove portion are alternately connected is accurately detected, and the tracking servo is then detected in the groove portion. It is necessary to switch the servo polarity to be applied to the recording track or to the recording track between the grooves.
[0006]
Now, a description will be given of how to insert an identification signal prepit in an optical disk medium driven by the land / groove recording type optical disk apparatus described above. In the land / groove recording method, there are three known methods for inserting the identification signal prepit as shown in FIG. In the method shown in FIG. 11A, which is also called a land / groove independent address system, a unique sector address is assigned to each of the land track sector and the groove track sector. If the pit width representing the identification signal is the same as the groove width, the identification signal pre-pits of the sectors of adjacent tracks are connected and the signal cannot be detected. Therefore, the pit width of the identification signal is narrower than the groove width. , About half of the groove width. However, at this time, grooves and prepits having different widths cannot be continuously formed unless the beam diameters of the beam for cutting the prepit and the beam for cutting the groove are changed in the optical disk master production process. Therefore, the master disk must be cut using two beams, a groove cutting beam and a pit cutting beam. If the centers of the two beams are deviated, a tracking offset occurs during the reproduction of the identification signal prepit and during the recording / reproduction of the information recording signal, which deteriorates the quality of the reproduced data. Specifically, the error rate increases due to the tracking error, leading to a decrease in data reliability. For this reason, high accuracy is required for the alignment of the two beams, which causes a cost increase in the disk master production process.
[0007]
Considering such circumstances, the method shown in FIG. 11B or FIG. 11C in which grooves and pits can be cut with a single beam is preferable from the viewpoint of accuracy and cost of disk manufacture. FIGS. 11B and 11C show a method of adding an identification signal pre-pit that can make the groove width and the pre-pit width substantially equal.
FIG. 11B shows a conventional optical disk described in JP-A-6-176404, which is also called a land / groove shared address system. In this system, identification signal prepits are arranged near the center of a pair of adjacent groove tracks and land tracks, and the same identification signal prepits are shared by both tracks.
[0008]
FIG. 11C shows a time division L / G independent address system. An independent address is added to each of the land track and the groove track, but the prepits of the identification signals are shifted in the direction parallel to the tracks so that the prepits of the identification signal are not adjacent to each other in adjacent tracks. It is. An example is disclosed in JP-A-5-282705.
[0009]
When applying the sector address assignment method applied to the conventional land / groove disk to the optical disk having the SS-L / G format shown in FIG. 10, the following problems arise. For example, the identification signal pre-pit is shifted by a certain amount (such as 1/4 of the track pitch) in the radial direction from the center of the groove by the method shown in FIG. Consider the case. In the SS-L / G format optical disk, the recording track in the groove and the recording track in the groove are connected once per recording track. FIG. 12 shows an arrangement diagram of recording tracks on the disk before and after the connection point in this case. In the recording sector, an identification signal pre-pit is added to the front of the recording track in the groove, and the identification signal pre-pit is displaced from the groove center in the radial direction, for example, by 1/2 of the groove width from the outer periphery side. Will be placed. Although nothing is recorded at the position of the identification signal prepit of the recording track in the groove portion, the identification signal of the adjacent track (recording track in the groove portion) on the inner peripheral side protrudes. A light spot scans the recording track in order to record / reproduce information. The identification signal of the recording track in the groove is detected because the outer half of the light spot is modulated by the identification signal preformatted. During scanning of the recording track in the groove portion, the identification signal of the track in the groove portion on the inner circumference side is detected by modulating the inner half portion of the light spot. Therefore, the same identification signal is read by the recording track in the groove portion and the recording track in the groove portion adjacent to the outer peripheral side thereof. Since the system controller 121 recognizes whether the optical disk apparatus scans the groove portion or the inter-groove portion with the light spot (that is, the polarity of tracking), the recording sector is identified by the output of the address reproducing unit 114. This can be done by the address calculation unit 115 by using address information obtained from a certain identification signal and a control signal T2 coming from the system control unit.
[0010]
As shown in the figure, the address of the recording sector of the recording track in the groove next to a certain connection point is assumed to be #n. Assuming that the number of sectors of one recording track is N, when the recording track in the groove on the disk is traced once, the address of the sector of the recording track in the groove before the next connection point is # (n + N-1). . This sector is connected to the sector of the recording track in the groove portion through the connection point. Since the address of the sector in the groove portion is the same as the sector of the groove portion in contact with the inner peripheral side, Return. Similarly, when the recording track in the groove portion is traced once on the disk, the address becomes # (n + N-1) in the recording sector in the groove portion before the next connection point. This sector is connected to the sector of sector address # (n + N) of the recording track in the groove through a connection point. In the same manner, N recording sectors in the groove and N recording sectors in the groove are continuously connected alternately. FIG. 13 shows the change of the recording sector address when the recording spiral is traced in this way.
[0011]
In conventional optical discs such as compact discs and magneto-optical discs, only one of the grooves or the inter-groove portions is used as a recording track, so the information track generally forms one spiral, and the recordings are arranged on the spiral. Address numbers are assigned to the sectors in order. When accessing a sector, the relationship between the address number and the order before and after the sector was very easy to understand. On the other hand, when the conventional technique is applied to the SS-L / G recording disk, the sector address value and the position on the recording spiral do not change monotonously as shown in FIG. Hateful. The read recording sector address is temporarily replaced with an address value representing the sector order in consideration of the tracking polarity recognized by the apparatus, and the arrangement order on the recording spiral is known for the first time. Whenever a specific sector of such an optical disk is to be accessed on the optical disk device, such an address calculation is required. When performing random access, complicated address calculation is required every time, and the burden on the apparatus is large.
[0012]
This burden becomes more prominent in the format adopted for the high-density optical disc. The optical disk surface is divided into a plurality of zones, and the so-called ZCAV (Zoned Constant Angular Velocity) format or ZCLV (Zoned Constant Linear Velocity) format is used to increase the number of recording sectors constituting one recording track in the outer peripheral zone. In the disk, the number N of sectors per track shown in FIGS. 12 and 13 varies depending on the radial position on the disk. Therefore, as described above, the recording sector address and the tracking polarity are arranged in the order of arrangement on the recording spiral. The calculation for calculating the corresponding address is further complicated.
[0013]
Here, it is also conceivable to apply the L / G independent address system as shown in FIG. In the conventional example, Japanese Patent Laid-Open No. 5-282705 does not disclose any information on how to give an address, so the specific implementation method is unknown, but as an example, the groove part and the groove part are independent of each other. It is easily conceivable to assign consecutive addresses to. At this time, the relationship between the position on the recording spiral and the recording sector address is the same as that of the land / groove shared address method shown in FIG. The change is as shown in FIG.
However, unlike the case of FIG. 11B, it is not necessary to discriminate the land sector / groove sector from the tracking polarity on the drive device side, and it is slightly different in that it can be discriminated by the identification signal reproduced from the disk surface. Although it can be said that there has been progress, it has not yet solved the above-mentioned problem of complicated address calculation.
[0014]
Next, I will point out problems related to the servo system. In the SS-L / G system, recording is performed on both the land and the groove, so that the track density is high. For this reason, when the tracking offset is increased, the reproduction signal quality deteriorates due to crosstalk from the adjacent track, for example, the error rate increases due to an increase in jitter, or the cross erase that erases a part of the adjacent track occurs during recording. To do. The error signal causing the tracking offset is generated in combination by the optical head system, the track arrangement on the disk, and the servo circuit system, and therefore generally has different sizes for the land track and the groove track. In order to eliminate crosstalk and cross erase, it is necessary to perform offset compensation of different sizes for each land and groove track. In the conventional land / groove method, that is, a method in which only one groove track and one land track constitute each recording spiral, each track is continuously tracked for offset compensation according to each land / groove track. During the process, it took some time, and after the adjustment, the compensation amount could be maintained, so that the offset compensation could be easily performed. However, in the SS-L / G disc, the switching of the tracking polarity between the land track and the groove track is performed at a high frequency of once per rotation of the disc, so that it is necessary to accurately perform the tracking offset compensation in a short time. .
[0015]
In the conventional method of inserting the identification signal into the land / groove recording described above, such offset compensation is not taken into consideration. For example, in the case of the land / groove shared address system shown in FIG. 11B, the pit is only on one side during the reproduction of the identification signal, so that the tracking offset is increasing. Further, in the case of the L / G independent address system as shown in FIG. 11C, the same applies to the case shown in FIG. 11B, but it is difficult to detect the tracking offset.
[0016]
[Problems to be solved by the invention]
Since the conventional land / groove recording optical disk medium is configured as described above, the calculation of the recording sector address becomes complicated when the identification signal adding method is applied to the single spiral land / groove recording format as it is. was there.
[0017]
In addition, the single spiral land groove recording format has a problem that it is difficult to detect a tracking offset while it is necessary to perform tracking offset compensation accurately in a short time.
[0018]
Further, in the single spiral land / groove recording format, a method capable of easily detecting the connection point between the land track and the groove track is required.
[0019]
The present invention has been made to solve the above problems, and is an optical disc in which recording tracks in grooves and recording tracks in grooves are alternately connected to form one recording spiral. An object of the present invention is to provide a method of creating an optical disc master for obtaining an optical disc in which the sector addresses of all the recording sectors are numbered in the order arranged on the recording spiral.
[0020]
In addition, an optical disk capable of accurately performing tracking offset compensation in a short time is obtained in an optical disk in which recording tracks in the groove and recording tracks in the groove are alternately connected to form one recording spiral. An object of the present invention is to obtain a method for creating an original optical disc.
[0021]
Further, in the optical disk in which the recording track in the groove portion and the recording track in the groove portion are alternately connected to form one recording spiral, an optical disk capable of easily detecting the connection point between the land track and the groove track is obtained. An object of the present invention is to obtain a method for creating an original optical disc.
[0022]
[Means for Solving the Problems]
The optical disk medium of the present invention is an optical disk medium in which groove tracks and groove tracks are alternately connected to form a continuous recording spiral, and the groove tracks and groove tracks adjacent to each other are aligned in the radial direction. The sector address information of each sector is recorded in one identification information area shared by the sectors aligned in the radial direction.
[0025]
Furthermore, when an integer value equal to or larger than the number of recording sectors constituting one recording track of the outermost zone is J, it is divided into a plurality of zones, and adjacent tracks in each zone in the radial direction. The difference between the aligned address values is J as described above.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings.
[0028]
Embodiment 1 FIG.
In the following embodiments, an optical disk having a single spiral land / groove recording (SS-L / G) format will be described. First, the physical layout is shown. FIG. 1 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in a recording sector of an optical disk medium according to Embodiment 1 of the present invention. In an SS-L / G format disc, there are two types of recording tracks, groove portions (grooves, concave portions) and groove portions (lands, convex portions), and the two recording tracks are alternately connected to form one recording spiral. The structure is designed to form. The recording sector includes a pre-pit identification signal and an information recording unit capable of recording user data and various management information. The identification signal consists of two parts, a front part and a rear part in the scanning direction, and the front part is displaced from the groove part to the outer peripheral side by 1/2 of the groove width. The rear part is displaced from the groove part to the inner peripheral side by ½ of the groove width.
[0029]
Next, a method for adding the address value of the identification signal will be described. The address of the groove is added to the identification signal immediately before the information recording unit, to the front identification signal that is displaced from the groove center to the outer circumference by ½ of the groove width. Further, the address of the groove part is the inner circumference side of the groove part from the groove center in the identification signal immediately before the information recording part of the recording track of the groove part on the outer peripheral side of the recording track in the groove part. Is added to the rear identification signal which is displaced. As a result, the address of the groove portion is added to the identification signal immediately before the information recording portion added to the rear portion identification signal that is displaced from the center of the groove portion to the outer peripheral side by 1/2 of the groove width. Become.
[0030]
This is because it is considered that the tracking offset generated when the disc master is cut is smaller when cutting the groove track and the groove address at the same time when cutting the recording track of the groove. From the viewpoint of tracking offset characteristics, if the tracking offset is smaller when cutting the groove track when cutting the groove track, and cutting the groove track when cutting the groove track, separately Cut it out.
As shown in the figure, when an address of a recording sector (groove portion in this figure) is #m (integer), and the number of sectors constituting one track is M (integer), the track goes around from the sector of address #m. The sector address is # (m + M). In the case of one more turn, # (m + 2M), thereafter # (m + 3M), # (m + 4M), the physical shape of the sector alternately changes between the groove and the inter-groove, but the address value changes linearly.
[0031]
Next, a description will be given of a method of adding an address at the connection portion between the land and the groove that are aligned in the radial direction of the disk once per disk. FIG. 2 is a schematic diagram for explaining the arrangement of the identification number prepits in the recording sector and the address values thereof at the boundary line between the optical disk medium land and the groove according to the first embodiment of the present invention. In the SS-L / G format disc, there is a boundary line connecting a recording track at one groove portion and a recording track at an inter-groove portion in the radial direction. Similar to the arrangement of the identification signals other than the boundary portion, the identification signal is arranged so that the front portion is displaced from the groove portion to the outer peripheral side by ½ of the groove width. The rear part is displaced from the groove part to the inner peripheral side by ½ of the groove width. In addition to the addition of the address value, the address of the groove part is added to the front identification signal which is displaced from the groove part immediately before the information recording part to the outer periphery by 1/2 of the groove width. In addition, the address of the inter-groove portion is added to a rear identification signal that is disposed by being displaced from the inter-groove portion immediately before the information recording portion to the outer peripheral side by ½ of the groove width.
[0032]
As shown in the figure, when the address of a certain recording sector (groove in this figure) is #n (integer), and the number of sectors in one track is N (integer), the track is circled from the sector of address #n. The sector address is # (n + N). In the case of one more revolution, # (n + 2N), # (n + 3N), # (n + 4N), and the physical shape of the sector are alternately changed between the groove and the groove, but the address value changes linearly. To do. Also, when looking at the continuity before and after the boundary, the sector of the groove part is the identification signal of the first half displaced from the groove part to the outer peripheral side by 1/2 of the groove width, and the sector of the groove part is the groove from the groove part to the groove part. The address can be specified from the identification signal in the latter half that is displaced to the outer circumference by ½ of the width.
[0033]
FIG. 3 is a diagram showing the relationship between the position on the recording spiral and the recording sector address of the optical disk medium according to Embodiment 1 of the present invention. Regardless of the tracking polarity, that is, whether the track is a groove or a groove, a one-to-one address value is obtained. In a conventional optical disk apparatus that drives a land / groove optical disk medium, there are two types of corresponding areas, a groove and an inter-groove, for one physical address.
[0034]
Next, an apparatus for recording / reproducing the optical disk medium will be described. FIG. 4 is a block diagram showing the configuration of the optical disc apparatus according to Embodiment 1 of the present invention. In FIG. 4, 100 is an optical disk, 101 is a semiconductor laser, 102 is a collimating lens, 103 is a half mirror, 104 is an objective lens, 105 is a photodetector, 106 is an actuator, 107 is an optical head, 108 is a differential amplifier, 109 is Polarity inversion unit, 110 tracking control unit, 111 addition amplifier, 112 waveform shaping unit, 113 reproduction signal processing unit, 114 address reproduction unit, 116 traverse control unit, 117 traverse motor, 118 recording signal processing 119 is a laser drive unit, 120 is a drive unit, and the above is basically the same as the conventional optical disc apparatus shown in FIG. Omitted.
[0035]
A configuration of a portion different from FIG. 9 will be described. Reference numeral 1 denotes an address extraction unit that receives a digital signal from the waveform shaping unit, a tracking error signal from the differential amplifier 108, and a control signal T1 from the system control unit, and outputs an address signal to the address reproduction unit 114. is there. 2 outputs control signals T1 to T4 to the address extraction unit 1, polarity inversion unit 109, tracking control unit 110, traverse control unit 116, LD drive unit and recording signal processing unit 118, and inputs an address signal from the address calculation unit 115. System control unit.
[0036]
The operation of the optical disk apparatus according to the first embodiment configured as described above will be described focusing on an address recognition method. Now, assume that the light spot is scanning the groove. At this time, the system control unit 2 outputs an L level signal corresponding to the groove portion to the control signal T1 indicating the polarity. The address extraction unit receives this control signal T1, and recognizes that the first half of the identification signal is the sector address between the next grooves. The tracking error at this time indicates that the identification signal of the first half is shifted to the outer periphery of the disk by 1/2 of the groove width with respect to the groove, so that the tracking error signal is greatly shifted to the inner periphery. This also confirms that the read identification mark is correct.
[0037]
On the contrary, it is assumed that the light spot scans between the grooves. At this time, the system control unit 2 outputs an H level signal corresponding to the groove portion as a control signal T1 representing polarity. The address extraction unit receives this control signal T1 and recognizes that the latter half of the identification signal is the sector address between the next grooves. The tracking error at this time indicates that the identification signal in the latter half is shifted to the outer periphery of the disk by ½ of the groove width with respect to the inter-groove portion, so that the tracking error signal is greatly shifted to the inner periphery. This also confirms that the read identification mark is correct.
[0038]
The address data output from the address extracting unit has a one-to-one correspondence with the physical sector address, and the address of the recording sector is uniquely determined by the read address data regardless of the groove portion and the groove portion. Can be determined.
[0039]
As described above, the first address information part, which is a part of the identification signal, is arranged with a certain amount of displacement from the center of the groove part in one radial direction, and the first address information part, which is the other part of the identification signal. The second address information portion is disposed in the other radial direction from the center of the groove portion, being displaced by the same amount as the predetermined amount, and the first address information portion represents the address of the recording sector of the groove portion, By expressing the address of the recording sector in the inter-groove part adjacent to the groove part in the second address information part, regardless of whether the address value obtained from the identification signal is the groove part or the inter-groove part, Since there is a one-to-one correspondence, there are no two sectors with the same address, such as k in the groove address (k is an integer) and k in the groove address. Address groove It is possible to uniquely determine regardless the land part.
[0040]
In addition, by assigning the address of the recording sector so as to monotonously increase or monotonously decrease in the order arranged on the recording spiral, regardless of whether the recording sector is a recording sector in a groove portion or a recording sector in an inter-groove portion. The address calculation becomes very simple, and the control program of the device and the access control circuit can be simplified.
[0041]
Furthermore, as another function and effect, the track offset correction will be described. The tracking offset amount can be detected by providing a pair of track offset detection pits displaced by a certain amount from the track center to the left and right as used in the sample servo optical disk. When the light beam passes through the middle of the track offset detection pit pair, the reproduction signal amplitude of the detection pit pair becomes equal. When off-tracking on one side, the playback signal amplitude of the pit on one side increases and the playback signal amplitude of the pit on the other side decreases, so that the track offset amount of the light beam can be detected and corrected. The light beam can be controlled to pass through the center of the track. In the present invention, the same principle and effect can be incorporated into the single spiral land groove recording format.
[0042]
Assume that the light beam enters the identification signal area of the next groove recording sector from the information recording area in the specific groove recording sector. Since the head of the identification signal is shifted by ½ of the groove width on the outer periphery of the disk, a corresponding tracking error signal is output. After a while, since there is an identification signal shifted by ½ of the groove width on the inner circumference of the disk, a tracking error signal corresponding to it is output. If these two error signals are ideally detected in contrast, the track center is scanned. Therefore, it becomes possible to control the servo to the center of the track by repeating the identification signal shifted to the inner periphery and the outer periphery.
[0043]
Embodiment 2. FIG.
The optical disk recording medium according to the second embodiment will be described below. FIG. 5 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in the recording sector of the optical disk medium according to the second embodiment of the present invention. The second embodiment is characterized in that identification signals are multiplexed. As shown in the figure, the identification signal is a record in which address information is recorded twice in each of the two identification signals (identification signal pairs) at the front and rear in the scanning direction shown in FIG. is there. The front part of the identification signal pair is displaced from the groove part to the outer peripheral side by 1/2 of the groove width, and the rear part of the identification signal pair is displaced from the groove part to the inner peripheral side by 1/2 of the groove width. This is the same as in the previous embodiment. Further, in the present embodiment, the data is recorded in a duplex manner, but a triple or quadruple configuration may be used.
[0044]
By adopting such a configuration, since the address information is multiplexed and recorded, the read error rate of the address information in the identification signal is reduced.
[0045]
Embodiment 3 FIG.
An optical disk recording medium according to Embodiment 3 will be described below. FIG. 6 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in the recording sector of the optical disk medium according to Embodiment 3 of the present invention. The third embodiment is characterized in that identification signals are multiplexed. As shown in the figure, the identification signal is a double recording of two identification signals (identification signal pairs) at the front and rear in the scanning direction shown in FIG. 1 of the first embodiment. The front part of the identification signal pair is displaced from the groove part to the outer peripheral side by 1/2 of the groove width, and the rear part of the identification signal pair is displaced from the groove part to the inner peripheral side by 1/2 of the groove width. This is the same as in the previous embodiment. Further, in the present embodiment, the data is recorded in a duplex manner, but a triple or quadruple configuration may be used.
[0046]
By adopting such a configuration, since the address information is multiplexed and recorded, the read error rate of the address information in the identification signal is reduced. The difference from the second embodiment is that the address information is improved because the addresses of the groove portions and the inter-groove portions are multiplexed and recorded at separate locations. However, since each address information section has to start from the synchronization pull-in of the reproduction signal, there is a disadvantage that the overhead on the format is large.
[0047]
As another function and effect, it goes without saying that the same principle and effect used in the sample servo type optical disk can be incorporated into the single spiral land groove recording format as shown in the first embodiment. Yes. At this time, by alternately recording a plurality of sets of the first address information portion and the second address information in the identification signal, it is possible to extend the time for detecting the tracking error and improve the accuracy. The identification signal can be used to make the servo track king correction easier and more accurate.
[0048]
Embodiment 4 FIG.
In the first embodiment, when one recording track is composed of N recording sectors, the address is set so as to increase the recording sector address by N when the recording spiral is followed by one track. . However, if the position on the recording spiral and the recording sector address are given so as to monotonously increase or monotonously decrease, the address calculation is considerably simplified. When it is easier to create an access system as a system by skipping the recording sector address in the middle of the system configuration, it is possible to assign a recording sector address as shown in FIG. FIG. 8 shows the relationship between the position on the recording spiral and the recording sector address.
[0049]
In the fourth embodiment, an example is shown in which the address is set so that the address of the recording sector is increased by (N + k) when the recording spiral is followed by one track. When two tracks are traced on the recording spiral, the address of the recording sector increases by (2N + 2k). For example, (N + k) is set to a constant value larger than the recording sector constituting one recording track of the outermost zone, and k is reversed by an amount corresponding to the change in the number N of recording sectors per recording track in each zone. It is also possible to change the sector address difference between adjacent tracks to be always constant. Since the light spot always reads the address information of one adjacent sector during tracking the track in the groove part and tracking the track in the groove part, if such a mechanism is incorporated, the address of the own sector will be read. When information cannot be read due to an error, it can be referred to and supplemented. It can also be used to constantly read both addresses and increase the degree of multiplexing of address information.
[0050]
In the ZCAV format and the ZCLV format, the number of recording sectors per track differs depending on the zone on the disk. However, if the length of one track varies depending on the zone, the address management of the connection point between the land track and the groove track becomes complicated. At this time, the address management can be simplified by adopting the method shown in the fourth embodiment.
[0051]
Even in this case, the address and the recording sector have a one-to-one correspondence regardless of whether the address value obtained from the identification signal is a groove portion or an inter-groove portion. The fact that there are no two address sectors and the sector address can be uniquely determined regardless of the groove part and the groove part is not lost.
[0052]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0053]
In the optical disk medium of the present invention , address information is made to correspond to a sector on a one-to-one basis, and a sector address can be uniquely determined regardless of whether it is a groove recording track or a groove recording track.
[0055]
Further, when the address information of the target sector cannot be read due to a read error, it can be complemented by referring to the address information of the sector of the adjacent track. It is also possible to always read both addresses and increase the degree of multiplexing of the address information, so that the read reliability of the address information can be improved. Further, the address management of the connection point between the land track and the groove track can be simplified with the ZCAV formatter and the ZCLV format.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in a recording sector of an optical disk medium according to Embodiment 1 of the present invention.
FIG. 2 is a schematic diagram for explaining an arrangement of identification number prepits in a recording sector and an address value thereof at a boundary line between an optical disk medium land and a groove according to the first embodiment of the present invention.
FIG. 3 is a diagram showing a relationship between a position on a recording spiral and a recording sector address of the optical disk medium according to the first embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of an optical disc apparatus according to Embodiment 1 of the present invention.
FIG. 5 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in a recording sector of an optical disk medium according to Embodiment 2 of the present invention.
FIG. 6 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in a recording sector of an optical disc medium according to Embodiment 3 of the present invention.
FIG. 7 is a schematic diagram for explaining the arrangement of identification number prepits and their address values in a recording sector of an optical disk medium according to Embodiment 4 of the present invention.
FIG. 8 is a diagram showing a relationship between a position on a recording spiral of an optical disk medium according to Embodiment 4 of the present invention and a recording sector address.
FIG. 9 is a block diagram showing a configuration of a conventional optical disc apparatus.
FIG. 10 is a diagram showing an optical disc having a format in which a recording track of a conventional groove portion and a recording track of the inter-groove portion are alternately connected to form one recording spiral.
FIG. 11 is a diagram showing how to insert an identification signal pre-pit in the conventional land / groove recording method.
FIG. 12 is a schematic diagram for explaining an arrangement of identification number prepits in a recording sector and an address value thereof at a boundary line between a conventional optical disc medium land and groove.
FIG. 13 is a diagram showing a relationship between a position on a recording spiral of a conventional optical disc medium and a recording sector address.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Address extraction part, 2 System control part, 100 Optical disk, 101 Semiconductor laser, 102 Collimate lens, 103 Half mirror, 104 Objective lens, 105 Photo detector, 106 Actuator, 107 Optical head, 108 Differential amplifier, 109 Polarity inversion part , 110 tracking control unit, 111 addition amplifier, 112 waveform shaping unit, 113 reproduction signal processing unit, 114 address reproduction unit, 115 address calculation unit, 116 traverse control unit, 117 traverse motor, 118 recording signal processing unit, 119 laser driving unit , 120 drive unit, 121 system control unit.

Claims (1)

Sector address information of each of the radially aligned sectors of the groove track and the groove track adjacent to each other in the optical disk medium in which the groove track and the groove track are alternately connected to form a continuous recording spiral Are recorded in one identification information area shared by the sectors aligned in the radial direction, and are divided into a plurality of zones, and the same as or more than the number of recording sectors constituting one recording track of the outermost zone An optical disc medium, wherein a difference between address values aligned in the radial direction of adjacent tracks in each zone is J, where J is a larger integer value .

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