WO2007138915A1

WO2007138915A1 - Recording medium

Info

Publication number: WO2007138915A1
Application number: PCT/JP2007/060392
Authority: WO
Inventors: Masahiro Kato; Keiji Katata; Masayoshi Yoshida; Takeshi Koda
Original assignee: Pioneer Corporation
Priority date: 2006-06-01
Filing date: 2007-05-21
Publication date: 2007-12-06

Abstract

A recording medium (100) is provided with a first recording layer (L0) including a first area (105) and a second recording layer (L1) including a second area (115). One end of the second area is at a position shifted from one end of the first area toward the other end. Prerecording areas (121, 122) whereupon recording information is previously recorded are arranged adjacent to the one end of the second area.

Description

Specification

recoding media

Technical field

[0001] The present invention relates to a technical field of a recording medium such as a DVD.

Background art

For example, in information recording media such as CD-ROM (Compact Disc-Read Only Memory), CD-R (Compact Disc Recordable), and DVD-ROM, as described in Patent Documents 1 and 2, etc. An information recording medium such as a multi-layer or dual-layer optical disc in which a plurality of recording layers are laminated or bonded on the same substrate has been developed. In an information recording apparatus such as a DVD recorder for recording on such a dual layer type optical disc, the recording layer located closest to the laser beam irradiation side (ie, the side closest to the optical pickup) is used. (In this application, it is referred to as “L0 layer” as appropriate.) By condensing the laser beam for recording, the thermal change recording method by heating data etc. to the L0 layer! / Or phase change recording method The recording layer located on the far side of the L0 layer (that is, the side far from the optical pickup force) as viewed from the laser beam irradiation side through the L0 layer or the like (referred to as “L1 layer” in this application as appropriate) By condensing the laser beam, information is recorded on the L1 layer by a thermal change recording method such as heating or a phase change recording method.

[0003] On the other hand, Patent Documents 1 and 2 further disclose a technique in which a ROM area in which data is recorded in advance by embossed pits or the like is arranged on a multilayer type or dual layer type optical disc. .

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-304730

Patent Document 2: JP-A-2005-78727

Disclosure of the invention

Problems to be solved by the invention

[0005] However, it is difficult for the user to provide a ROM area such as embossed pits on the information recording medium or an area in which data is recorded in advance before shipping the disk (both referred to as a pre-recording area in the present application). Freely recordable area part (eg user data area) This will lead to a decrease in capacity.

The present invention has been made in view of, for example, the conventional problems described above. For example, a pre-recording area can be arranged without reducing the capacity of an area where a user can freely record data as much as possible. It is an object of the present invention to provide a recording medium that makes it possible.

Means for solving the problem

[0007] Hereinafter, the recording medium of the present invention will be described.

In order to solve the above problems, a recording medium of the present invention includes a first recording layer including a first area and a second recording layer including a second area, and one of the second areas The end of the first area (for example, the inner peripheral side) is located at a position shifted to the other side (for example, the outer peripheral side) different from the one side than the one end of the first area, Adjacent to one end of the second area is a pre-recording area where recording information is recorded in advance.

[0009] According to the recording medium of the present invention, the recording information is recorded in each of the first recording layer and the second recording layer. Specifically, the first recording layer includes at least a first area, and the second recording layer includes at least a second area. The user can freely record the record information in at least the first area and the second area. In other words, the first area and the second area are areas where recording information can be appropriately recorded.

[0010] In the present invention, in particular, the end on one side of the second area is located at a position where the end force on one side of the first area is also shifted to the other side. In other words, the end of one side of the second area is located at a position shifted to the other side of the area partial force of the second recording layer corresponding to the end of one side of the first area. Here, “corresponding” is intended to indicate that it exists at a substantially opposite position (for example, substantially the same radial position) by design, and in an actual recording medium, it is not necessarily opposite due to the influence in the manufacturing process. It is not always in the position to do. In this case, “facing” means a relationship that is actually at the same radial position. A pre-recording area in which recording information is recorded in advance, for example, by embossed pits or actual recording, is arranged adjacent to one end of the second area.

[0011] In this way, the end portion on the one side of the second area is located at the position where the area partial force of the second recording layer corresponding to the end portion on the one side of the first area is shifted to the other side. For example, a positional shift with respect to an area (or area address) on a recording medium due to some cause. Even if such a situation occurs, the end on one side of the second area is not located further on the one side than the end on one side of the first area. That is, even when positional deviation or the like occurs, when recording information is recorded in the second area, laser light is irradiated through the first area. Therefore, if recording information is recorded in the second area after recording information in the first area, the recording conditions of the recording information recorded in the second area can be unified. In other words, it is possible to favorably maintain a recording order that is important in a two-layer or multilayer recording medium.

[0012] In order to maintain the recording order, the pre-recording area is arranged adjacent to the second area that is smaller than the first area. In other words, the prerecorded area is included in the area excluded from the second area in order to maintain the recording coder even though it is included in the second area where the recorded information can be recorded. Can be placed. In other words, there is no need to provide a pre-recording area inside the first area or the second area. As a result, it is possible to arrange a pre-recording area on the recording medium without reducing the capacity of the area portion (that is, the first area or the second area) where the user can freely record the recorded information.

[0013] As described above, pre-recording can be performed while preferably recording information on a two-layer or multilayer recording medium, and reducing as much as possible the capacity of an area where the user can freely record the recording information. The area can be arranged on the recording medium.

[0014] One aspect of the recording medium of the present invention is that at least one end of the second area on the one side of the second area is at least on the other side of the end on the one side of the first area. In addition, each of the second recording layers is located at a position shifted by a tolerance length indicating the sum of an allowable range of positional deviation from the predetermined position of the address to be defined at the predetermined position.

[0015] In this aspect, the one end portion of the second area is at least a tolerance length shifted to the other side of the area partial force of the second recording layer corresponding to the one end portion of the first area. To position. Note that the “tolerance length” is the tolerance of the positional deviation from the predetermined position of the address to be defined at a predetermined position (for example, a predetermined radial position) in the design in each of the first recording layer and the second recording layer. Indicates the sum of ranges. That is, the “tolerance length” is a predetermined position in the first recording layer where the predetermined address is specified by design and the actually manufactured recording medium. The allowable range of positional deviation with respect to the address position, the position of the second recording layer where the predetermined address is specified by design, and the positional deviation between the position of the predetermined address on the actually manufactured recording medium. It is the sum of the allowable range.

[0016] Thereby, even if address misalignment or the like occurs, it is possible to suitably maintain the recording order that is important in a two-layer type or multilayer type recording medium, and the user can record information. The pre-recording area can be arranged on the recording medium without reducing the capacity of the area where recording can be freely recorded.

[0017] As described above, one end of the second area is located at a position shifted at least by the tolerance length from the second recording layer area corresponding to the one end of the first area to the other side. In an aspect of the recording medium, one end portion of the second area has (0) the focal length of the laser beam for recording the recording information on the recording medium in addition to the tolerance length. The allowable maximum value of the spot radius of the laser beam on the first recording layer and the relative tolerance of the relative eccentricity of the GO between the first recording layer and the second recording layer. From the sum of the maximum values, (iii) at least part of the laser beam irradiated to record the recording information on the second recording layer is an area of the first recording layer where the recording information is not recorded. The second recording layer is irradiated through the portion.ヽ but when allowed, it may also be configured to be positioned in the recording information has clearance length shift minus the magnitude of the allowable maximum value of the area portion of the first recording layer is not recorded position

[0018] According to this aspect, in addition to the positional deviation of the address generated in the manufacturing process of the recording medium, the eccentricity deviation is recorded in the area of the laser beam spot size and the recorded information. Each of the first area and the second area is formed in consideration of an allowable value with which laser beams can overlap. Therefore, it is possible to record the recording information on each recording layer more preferably.

[0019] In another aspect of the recording medium of the present invention, an end portion on the other side of the second area is located at a position shifted to one side with respect to an end portion on the other side of the first area. The pre-recording area is disposed adjacent to the other end of the second area.

[0020] According to this aspect, the pre-recording area is arranged so as to be adjacent to both end portions of the second area. Is done. Therefore, the recording order can be suitably maintained at the end portions on both sides of the second area (for example, on each of the inner circumference side and the outer circumference side of the recording medium) (that is, the recording order over the entire surface of the recording medium). In addition, it is possible to arrange a pre-recording area on the recording medium that minimizes the capacity of the area where the user can freely record the recorded information.

[0021] As described above, the other end portion of the second area is located at a position shifted to one side with respect to the other end portion of the first area, and at the other end portion of the second area. In an aspect of the recording medium in which the pre-recording area is arranged adjacently, the other end of the second area is at least one of the first recording to one side of the other end of the first area. In each of the recording layer and the second recording layer, an address to be defined at a predetermined position may be positioned at a position shifted by a tolerance length indicating a sum of an allowable range of positional deviation from the predetermined position. .

[0022] With this configuration, even if address misalignment or the like occurs, the recording order can be suitably maintained at both ends of the second area, and the user can record recording information freely. A pre-recording area that minimizes the capacity of the possible area can be arranged on the recording medium.

[0023] As described above, in the aspect of the recording medium in which the end on the other side of the second area is located at a position shifted to the one side by the tolerance length from the end on the other side of the first area, In addition to the tolerance length, the end on the other side is (0) the first recording layer when the laser beam for recording the recording information on the recording medium is focused on the second recording layer. (Ii) the sum of the allowable maximum values of the relative decentering of the first recording layer and the second recording layer (iii) At least a part of the laser beam irradiated to record the recording information on the second recording layer is recorded with the recording information!,!, Through the area portion of the first recording layer. When the second recording layer is allowed to be irradiated, the recorded information is recorded. Has been a ヽ, it be configured so as to be located at a position clearance length shift by subtracting the maximum allowable size of the area portion of the first recording layer! /,.

With this configuration, the position of the address generated during the manufacturing process of the recording medium, etc. In addition to the misalignment, the first area and the second area take into account the tolerance that the laser beam can be overlapped with the area where the laser beam spot size and recorded information are recorded and the laser beam does not overlap. Each is formed. Therefore, it is possible to more suitably record the recording information on each recording layer.

In another aspect of the recording medium of the present invention, dummy information is recorded in advance in the pre-recording area in addition to the recording information.

[0026] According to this aspect, even if the capacity of the recording information prerecorded in the prerecording area is small, the prerecording area can be arranged by recording dummy information, for example, which is meaningless.

In another aspect of the recording medium of the present invention, the tolerance length is 40 μm in the radial direction of the recording medium.

[0028] According to this aspect, for example, in DVD-R and DVD-RW which are standard recording media, the allowable range of positional deviation in each recording layer is specified as -20 μm to +20 μm. It has been. Therefore, for example, when the positional deviation of the first recording layer is +20 m and the positional deviation of the second recording layer is 20 m, there is a relative distance of 40 m between the first recording layer and the second recording layer. Misalignment occurs. That is, a relative positional shift of 40 m at maximum is allowed between the first recording layer and the second recording layer. Therefore, by forming the first area and the second area based on the tolerance length in consideration of this allowable range, it is possible to suitably enjoy the various benefits described above. Of course, if a different value is defined as an allowable range of misalignment in other standards, it is preferable to use that value instead of 40 μm.

In another aspect of the recording medium of the present invention, the clearance length is 65 μm in the radial direction of the recording medium.

[0030] According to this aspect, for example, a DVD-R or DVD-RW, which is one standard of a recording medium, has a clearance length of, for example, 65 m. Therefore, by forming the first area and the second area based on the clearance length, it is possible to suitably enjoy the various benefits described above. Of course, if a different value is defined as the clearance in other standards, it is preferable to use that value instead of 65 μm.

In another aspect of the recording medium of the present invention, the first recording layer includes the one side or the other The recording information is recorded toward the other side, and the recording information is recorded on the second recording layer toward a side different from the side on which the recording information is recorded in the first recording layer.

[0032] According to this aspect, the above-described various benefits can be enjoyed with the opposite track path type recording medium.

[0033] These effects and other advantages of the present invention will become more apparent from the embodiments described below.

[0034] As described above, in the recording medium of the present invention, the end on one side of the second area is located at a position shifted to the other side from the end on one side of the first area. A pre-recording area in which recording information is recorded in advance is arranged adjacent to one end of the second area. Therefore, for example, the pre-recording area can be arranged without reducing the capacity of the area where the user can freely record data as much as possible.

Brief Description of Drawings

FIG. 1 is a schematic plan view showing a basic structure of an optical disc according to the present embodiment, a schematic sectional view of the optical disk, and a radial direction associated with the schematic sectional view in the radial direction. FIG. 5 is a schematic conceptual diagram of an area structure.

FIG. 2 is a data structure diagram conceptually showing a specific area configuration of the optical disc in the example.

FIG. 3 is a schematic conceptual diagram conceptually showing relative tolerance.

FIG. 4 is a schematic conceptual diagram conceptually showing an eccentric clearance among the clearances.

FIG. 5 is a schematic conceptual diagram conceptually showing spot clearance among clearances.

FIG. 6 is a schematic conceptual diagram conceptually showing overlap clearance among clearances.

FIG. 7 is an area structure diagram conceptually showing a specific address relationship between a data area and a ROM area on an optical disc.

FIG. 8 is a graph used to calculate an address offset.

FIG. 9 is a data configuration diagram conceptually showing another specific area configuration on the optical disc.

FIG. 10 is a data configuration diagram conceptually showing another specific area configuration on the optical disc. FIG. 11 is a data configuration diagram conceptually showing another specific area configuration on the optical disc.

[0036] 100 optical disc

105, 115 Data area

121, 122 ROM area

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described for each embodiment in order with reference to the drawings.

[0038] (1) Basic structure

First, the basic structure of an optical disc as an embodiment of the recording medium of the present invention will be described with reference to FIG. FIG. 1 is a schematic plan view showing the basic structure of the optical disc 100 according to the present embodiment, and is a schematic sectional view of the optical disc 100 and its radial direction associated with the schematic sectional view. It is a schematic conceptual diagram of the area structure in FIG.

As shown in FIG. 1 (a), the optical disc 100 is, for example, a lead-in area 102 or lead-out centered on a center hole 101 on a recording surface on a disc body having a diameter of about 12 cm as in the case of DVD. An area 118, a data area 105 constituting a specific example of “first area” in the present invention, a data area 115 constituting a specific example of “second area” in the present invention, and middle areas 109 and 119 are provided. It has been. In the optical disc 100, a recording layer or the like is laminated on a transparent substrate 110. In each recording area of the recording layer, for example, tracks such as a groove track and a land track are alternately provided in a spiral shape or a concentric shape around the center hole 101. On this track, data is divided and recorded in units of ECC blocks. The ECC block is a data management unit in which recorded information can be error-corrected.

It should be noted that the present invention is not particularly limited to the optical disc having such three areas.

For example, even if the lead-in area 102, the lead-out area 118, or the middle area 109 (119) does not exist, the data structure described below can be constructed. Also, as will be described later In addition, the lead-in area 102, the lead-out area 118, or the middle area 109 (119) may be further subdivided.

In particular, as shown in FIG. 1B, the optical disc 100 according to this example includes, for example, a LO layer that constitutes an example of the first and second recording layers according to the present invention on a transparent substrate 110. And L1 layer has a laminated structure. At the time of recording / reproduction of such a two-layer type optical disc 100, depending on which recording layer the condensing position of the laser beam LB irradiated from the lower side to the upper side in FIG. Data recording / reproduction in the L0 layer is performed or data recording / reproduction in the L1 layer is performed. In particular, in the L0 layer, data is recorded from the inner circumference side to the outer circumference side, while in the L1 layer, data is recorded from the outer circumference side to the inner circumference side. That is, the optical disc 100 according to the present embodiment corresponds to an opposite track path type optical disc. However, even in the case of a parallel track path type optical disc, it is possible to enjoy various benefits described below by adopting the configuration described below.

[0042] In addition, in the special data area 105 (115) of the optical disc 100, data is recorded in the data area 115 of the L1 layer after data is recorded in the data area 105 of the L0 layer in principle. That is, by irradiating the laser beam LB through the data area 105 of the L0 layer where data is recorded, the data is recorded in the data area 115 of the L1 layer. In principle, data is recorded in the same manner for the lead-in area 102, the lead-out area 118, and the middle area 109 (119). This mode of data recording is called “recording order”.

In addition, the optical disc 100 according to the present embodiment may be two-layer single-sided, that is, not limited to dual layers, but may be two-layer double-sided, that is, dual-layer double-side. Furthermore, it is not limited to an optical disc having two recording layers as described above, and may be a multilayer type optical disc having three or more layers.

[0044] In the above description, the middle area 109 (119) has been described as having been fixed in position, but in the actual finalization process, the middle area 109 (119) may be arranged on the inner circumference side. . Even in this case, it is preferable that the area arrangement mode described below is satisfied. [0045] (2) Specific area configuration

Next, a specific area configuration of the optical disc 100 according to the present embodiment will be described with reference to FIGS. Here, the outline of a specific area configuration will be explained using FIG. 2, and supplementary or more detailed explanation will be added as appropriate using FIGS. FIG. 2 is a data structure diagram conceptually showing a specific area configuration of the optical disc 100 according to the present embodiment.

As shown in FIG. 2 (a), the end on the inner periphery side of the data area 115 of the L1 layer and the end portion on the inner periphery side of the data area 105 of the LO layer The relative tolerance that constitutes a specific example of the “tolerance length” of More specifically, the LO layer area portion corresponding to the inner circumferential end of the L1 layer data area 115 and the inner circumferential end of the LO layer data area 105 are relatively opposite in the radial direction. Tolerance is away. In other words, the inner end of the data area 115 in the L1 layer is located at a position that is relatively tolerance shifted from the inner end of the data area 105 in the LO layer toward the outer periphery. Yes.

Furthermore, the outer peripheral end of the L1 layer data area 115 and the outer peripheral end of the LO layer data area 105 are separated from each other in the radial direction. More specifically, the LO layer area portion corresponding to the outer edge of the L 1 layer data area 115 and the outer edge of the LO data area 105 are relatively opposite in the radial direction. Tolerance is away. In other words, the outer end of the data area 115 in the L1 layer is positioned at a position that is relatively tolerance shifted by directing more toward the inner periphery than the outer end of the data area 105 in the LO layer. The

[0048] It should be noted that the relative tolerance is an allowance of a positional deviation between a position where a predetermined address is originally designed in the LO layer and a position where the predetermined address is actually arranged on the optical disc 100. The sum of the range and the allowable range of positional deviation between the position where the predetermined address in the L1 layer should be originally arranged and the position where the predetermined address on the actual optical disc 100 is arranged is shown.

A ROM area 121 constituting a specific example of the “pre-recording area” in the present invention is disposed adjacent to the inner peripheral end of the data area 115 of the L1 layer. That is, the pre-record area 121 is arranged between the data area 115 and the lead-out area 118. The Similarly, a ROM area 122 is disposed adjacent to the outer peripheral end of the data area 115 of the L1 layer. That is, the pre-recording area 122 is arranged between the data area 115 and the middle area 119. Predetermined pre-data is recorded in advance in the ROM areas 121 and 122 when the optical disc 100 is manufactured, for example, by embossed pits or pre-marks.

[0050] The size (in other words, the length in the radial direction) of the ROM areas 121 and 122 may be the same as the relative tolerance, may be shorter than the relative tolerance, or may be longer than the relative tolerance. Also good. In short, the ROM area is arranged adjacent to the data area 115 which is smaller than the data area 105.

[0051] Alternatively, more preferably, as shown in FIG. 2 (b), the inner peripheral end of the L1 layer data area 115 and the inner peripheral end of the L0 layer data area 105 are In the radial direction, they are separated by the sum of relative tolerance and clearance. More specifically, the area portion of the L0 layer corresponding to the inner peripheral end of the data area 115 of the L1 layer and the end of the inner peripheral side of the data area 105 of the L0 layer are relatively relative to each other in the radial direction. Separated by the sum of tolerance and clearance. In other words, the inner edge of the L1 layer data area 115 is the L0 layer data area.

It is located at a position where the relative tolerance and the clearance are shifted together, with the force toward the outer peripheral side rather than the inner peripheral end of 105.

[0052] Further, the outer end of the data area 115 in the L1 layer and the outer end of the data area 105 in the L0 layer are in the radial direction by the sum of relative tolerance and clearance in the radial direction. is seperated. More specifically, the area portion of the L0 layer corresponding to the outer peripheral end portion of the data area 115 of the L1 layer and the end portion of the outer peripheral side of the data area 105 of the L0 layer are in the radial direction. In the radial direction, the sum of the relative tolerance and clearance is separated. In other words, the outer peripheral edge of the data area 115 in the L1 layer is directed to the inner peripheral side rather than the outer peripheral edge of the data area 105 in the L0 layer, so that the sum of relative tolerance and clearance is shifted. Located in

In addition, a ROM area 121 is disposed adjacent to the inner peripheral end of the data area 115 of the L1 layer. That is, the pre-record area 121 is arranged between the data area 115 and the lead-out area 118. Similarly, at the outer edge of L1 layer data area 115 A ROM area 122 is arranged adjacent to the ROM area 122. That is, the pre-record area 122 is arranged between the data area 115 and the middle area 119. The size (in other words, the length in the radial direction) of ROM areas 121 and 122 in Fig. 2 (b) may be the same as the sum of relative tolerance and clearance, or from the sum of relative tolerance and clearance. Can be shorter or longer than the sum of relative tolerance and clearance.

[0054] In the following description, it is preferable to consider such "clearance" even when the description of "relative tolerance" is in progress.

[0055] The clearance in the present embodiment is (i) a clearance related to eccentricity corresponding to a deviation of the center position of the LO layer and L1 layer (hereinafter referred to as "eccentric clearance" as appropriate), GO Based on the sum of the clearances related to the beam spot size of the defocused laser beam (hereinafter referred to as “spot clearance” where appropriate), (iii) when data is recorded on the L1 layer, no data is recorded. The laser beam LB is transmitted when it is allowed to irradiate a part of the laser beam LB to the L1 layer through an area portion of an L0 layer (hereinafter referred to as “unrecorded area” as appropriate). Subtract the maximum allowable value (hereinafter referred to as “overlap clearance” as appropriate) of the size of the unrecorded area of the L0 layer (that is, the laser beam LB force that may overlap the unrecorded area of the L0 layer). It corresponds to the value.

[0056] Here, the relative tolerance and the clearance will be described in more detail with reference to FIGS. Here, FIG. 3 is a schematic conceptual diagram conceptually showing relative tolerance, FIG. 4 is a schematic conceptual diagram conceptually showing an eccentric clearance among clearances, and FIG. FIG. 6 is a schematic conceptual diagram conceptually showing a spot clearance among clearances, and FIG. 6 is a schematic conceptual diagram conceptually showing an overlap clearance among clearances.

As shown in FIG. 3A, it is assumed that the address “X” is defined as the radial position “r” by design. As a result, the layout of the lead-in area 102, the data area 105 (115), the lead-out area 118, and the middle area 109 (119) is defined by design. At this time, a manufacturing error of a stamper or the like for forming a land pre-pit or wobble that defines an address (in other words, a manufacturing error of a disk master for manufacturing a stamper or the generation of the disk master). "X" due to the radial position error of the cutting machine and uneven track pitch) May not be precisely defined at the radial position "r" that should be originally defined. Or, due to individual differences in the thermal contraction of the disk substrate when manufacturing the optical disk 100, the address “X” may not be accurately defined at the radial position “r” that should be defined originally.

Specifically, as shown in FIG. 3B, the address “X + ΔΧ” may be defined at the radial position “r” where the address “X” should originally be defined. At this time, the address “X” may be defined at the radius position “r—Arl”, which is shifted to the inner circumference side by “Arl” from the radius position “r”. This Arl is called a positional shift for each recording layer. This misalignment can occur for each recording layer. That is, the positional deviation in the LO layer and the positional deviation in the L1 layer can occur independently of each other. In this case, it is preferable to define an allowable range of positional deviation from the viewpoint of ensuring a suitable recording operation or reproducing operation. For example, in a two-layer DVD-R or a two-layer DVD-RW that is a specific example of the optical disc 100, the allowable range of positional deviation is set to 20 μm to +20 μm. This allowable range of displacement is referred to as “position tolerance” as appropriate. Based on this allowable range, the maximum value of the sum of the allowable ranges of the positional deviations of the L0 layer and the L1 layer (that is, the sum of the positional tolerances of the L0 layer and the L1 layer) is the relative tolerance. In this case, the relative tolerance is 20 + 20 = 40 m.

Note that the relative tolerance may be the sum of the actual positional deviation of the L0 layer and the actual positional deviation of the L1 layer. That is, the relative tolerance of the optical disc 100 is the sum of the maximum value of the positional deviation actually generated in the L0 layer and the maximum value of the positional deviation actually generated in the L1 layer.

[0060] As shown in FIG. 4 (a), if the optical disc 100 has no relative eccentricity (hereinafter referred to as "relative eccentricity") between the LO layer and the L1 layer, The track specified by the radius “r” and the track specified by the radius “r” of the L1 layer are in a relationship of facing each other over one track. Eccentricity refers to the relative position of the L0 layer and L1 layer, which is caused by misalignment of the center position of each recording layer, misalignment of the center position when the L0 layer and L1 layer are bonded together, etc. Indicates a misalignment.

[0061] On the other hand, as shown in FIG. 4B, in the optical disc 100 in which relative eccentricity exists, the track defined by the radius “r” of the L1 layer and the radius “r” of the L1 layer The track specified in “ It only faces two points during one round of the rack. In other words, the L0 layer track that is originally defined at the opposite position and the L1 layer track do not face each other in most places, and the L0 layer is on the outer peripheral side of the L1 layer. The part which becomes the inner circumference side from the L1 layer occurs. Here "Ar2" is relative eccentricity. Therefore, as shown in Fig. 4 (c), the track radius of the LO layer corresponding to the track specified by the radius "r" of the L1 layer is set to "r + Ar2". Then, as shown in Fig. 4 (d), even if the relative eccentricity "Ar2" occurs, the track specified by the radius "r" of the L1 layer has the radius "r + Ar2" of the LO layer. It will no longer be outside the defined track. “Δι: 2” introduced in Fig. 4 (c) is the “eccentric clearance”. The maximum allowable relative eccentricity value is used as the eccentric clearance value.

Further, as shown in FIG. 5 (a), when the laser beam LB is focused on the L1 layer (focused), the LO layer has a predetermined radius “Ar3”. A beam spot is formed. At this time, as described above, consider the case where data is recorded in the L1 layer by irradiating the laser beam LB through the LO layer in which the data is recorded. As shown in FIG. 5 (a), when data is recorded up to the address “X” of the LO layer, the focus of the laser beam LB is focused on the address “γ” of the L1 layer facing the address “X”. In combination, the left half of the laser beam LB is applied to the L1 layer through the LO layer on which data is recorded, while the right half of the laser beam LB passes through the LO layer on which no data is recorded. The L1 layer is irradiated. Therefore, if data is simply recorded on the L1 layer facing the LO layer on which data has already been recorded, data can be suitably recorded on the L1 layer by irradiating the laser beam LB through the LO layer on which the data has been recorded. I can't do it.

Therefore, as shown in FIG. 5 (b), the focus position of the laser beam LB when data is recorded on the L1 layer is L1 facing the address “X” of the LO layer where the data is recorded. It is necessary to shift from the position indicated by the layer address “Y” to the inner circumference side by a distance corresponding to the radius “Ar3” of the beam spot. Specifically, it is necessary to focus the laser beam LB at the position indicated by the address “Υ—ΔΧ1” shifted inward by the address variable “ΔΧ1” corresponding to the radius “Ar3” of the beam spot. “Ar3” introduced in Fig. 5 (b) is “spot clearance”. The spot clearance value is the maximum allowable radius of the beam spot. [0064] However, as shown in FIG. 6, part of the laser beam LB when data is recorded in the L1 layer is an area of the LO layer in which the data whose width is indicated by Ar4 is not recorded. Even if it overlaps with the part, data can be suitably recorded in the L1 layer. This is because the laser light LB power on the L1 layer does not fluctuate enough to adversely affect data recording even if a portion of the laser light LB overlaps the LO layer where data has not been recorded. Because. In other words, in order to suitably record data in the L1 layer, it is necessary to irradiate the laser beam LB through the LO layer on which the data is recorded. Strictly speaking, a part of the laser beam LB is not yet recorded. The L1 layer may be irradiated through the LO layer of the recording. Specifically, as shown in FIG. 5 (b), the address “Υ-ΔXI” shifted to the inner circumference side by the variable “Δ Δ1” corresponding to the beam spot radius “A r3” is shown. Although it is necessary to focus the laser beam LB on the position, strictly speaking, it is suitable for the L1 layer even if the laser beam LB is focused on the position indicated by the address “Υ— Δ Χ2 (however, Δ Χ2 Δ ΔXI)” Can record data. At this time, a part of the laser beam LB may overlap! /, The maximum value force of the width Δr4 is “overlap clearance”.

[0065] “A r2” in FIG. 4 is changed to the maximum allowable relative eccentricity between the LO layer and L1 layer, and “A r3” in FIG. 5 is changed again to focus the laser beam LB on the L1 layer. If the maximum allowable value of the radius of the beam spot in the LO layer is determined, the maximum value of the width that may overlap the unrecorded area of the laser light LB force LO layer is changed from “A r4” in FIG. If so, the clearance in Fig. 2 is equivalent to "Δ Γ2 + Δ Γ3-Δ Γ4".

Next, with reference to FIG. 7 and FIG. 8, a specific address relationship between the data areas 105 and 115 and the ROM areas 121 and 122 on the optical disc 100 will be described. FIG. 7 is an area structure diagram conceptually showing a specific address relationship between the data areas 105 and 115 and the ROM areas 121 and 122 on the optical disc 100, and FIG. 8 calculates an address offset. It is a graph used for this.

[0067] As shown in FIG. 7 (a), the address of the inner edge of the data area 105 of the L0 layer is defined as "A", and the address of the outer edge of the data area 105 of the L0 layer is Set to "X". The address of the L0 layer and the address of the L1 layer are determined to be interpolated with each other at the same radial position. Specifically, it faces the inner edge of the L0 layer data area 105. The address of the area part of the LI layer is defined as “A-bar (in FIG. 7, the force with a horizontal line at the top of A, which is referred to as A-bar in this specification)” and LO The address of the area facing the outer edge of the layer data area 105 is “X-bar” (in FIG. 7, the force with a horizontal line at the top of X X-bar)). Further, the value obtained by converting the sum of the relative tolerance and the tailorance at the radial position indicated by the address “A” into the data size is defined as Ofs (A), and at the radial position indicated by the address “X”. Of s (X) is the value obtained by converting the sum of relative tolerance and clearance into data size.

In this case, as shown in FIG. 7 (a), the address of the end portion on the inner circumference side of the data area 115 of the L1 layer is “A + Ofs (A), similarly. The address of the outer edge of the layer data area 115 is “X—Ofs (X),”.

[0069] Further, as shown in FIG. 7 (b), the address is determined so that the address of the outer edge of the data area 105 and the address of the outer edge of the data area 115 are in an interpolating relationship. It's okay. Specifically, the address of the outer edge of the data area 115 is defined as “X-bar”.

In this case, as shown in FIG. 7 (b), the address of the area portion of the L1 layer facing the outer edge of the data area 105 is “−1 ^ + 0 £ 5 ()”. Identified. Further, the address of the area portion of the L1 layer facing the inner peripheral end of the data area 105 is specified by “A_bar + Ofs (X)”. Further, the address of the end portion on the inner peripheral side of the data area 115 is “A−bar + Ofs (X) + Ofs (A)”.

Note that FIG. 7 (a) and FIG. 7 (b) differ only in the manner of address assignment, and the arrangement relationship between the data areas 105 and 115 and the ROM areas 121 and 122 is the same.

[0072] 0 £ 3 (eight) and 0 £ 3 () are calculated based on the graphs shown in Figs. 8 (a) and 8 (b). Fig. 8 (a) shows the outermost circumference of an optical disk with a diameter of 12cm, for example (specifically, the position with a radial position force of 8.6mm, for example, near the outer edge of the data areas 105 and 115). 5 is a graph showing the relationship between the sum of relative tolerance (Tls) and clearance (Cls) and the address offset value (ie, the value obtained by converting the sum of relative tolerance and clearance into a data size). Figure 8 (b) is a graph showing the relationship between the radial position of the optical disc 100 and the address offset value when the sum of relative tolerance and clearance is 105 μm. is there.

[0073] The graph shown in FIG.

Ofs = 5. 4668 X (Tls + Cls) · · · · Equation (1)

Have the relationship. For this reason, for example, when Tls = 40 μm and Cls = 65 μm, the address offset value near the outer edge of the data areas 105 and 115 (ie, FIG. 7 (a) and FIG. Ofs (X) in 7 (b) becomes 5.4668 X 105 = 575ECC block.

[0074] The graph shown in FIG.

Ofs = 9. 8254 X radius position · · · · Equation (2)

Have the relationship. For this reason, the address offset value in the vicinity of the inner peripheral edge of the data areas 105 and 115 (that is, Of s (A) in FIGS. 7A and 7B is 9.8254 X 23. 6 = 233 ECC blocks Similarly, the address offset value near the outer edge of the data areas 105 and 115 (that is, Ofs (X) in FIGS. 7A and 7B is 9.8254). X 58. 6 = 575 ECC blocks.

As described above, the address offset value can be easily calculated by referring to the graphs shown in FIGS. 8 (a) and 8 (b). As a result, the data areas 105 and 115, and the RO Addressing of the M areas 121 and 122 can be suitably performed. Needless to say, the size of ROM areas 121 and 122 must also be taken into account when addressing.

The address offset value does not necessarily have to be calculated using the graphs shown in FIGS. 8 (a) and 8 (b). Expressions (1) and (2) may be used, or a conversion table may be used. In short, as long as the sum of relative tolerance and clearance can be suitably converted into an address value, the conversion may be performed by any method.

As described above, the inner peripheral end of the data area 115 is located at a position where the inner peripheral end force of the data area 105 is also shifted to the outer peripheral side. In addition, the end force on the outer peripheral side of the data area 105 is located at the position shifted to the inner peripheral side on the outer peripheral side of the data area 115. For this reason, for example, even if there is an address misalignment (further, eccentricity, etc.) due to some cause, when data is recorded in the data area 115, the data Laser light LB is irradiated through the data area 105. Therefore, if data is recorded in the data area 115 after the data is recorded in the data area 105, the recording conditions of the data recorded in the data area 115 can be unified. In other words, it is possible to favorably maintain a recording order that is important in a two-layer or multilayer recording medium.

The ROM areas 121 and 122 are arranged adjacent to the data area 115 that is smaller than the data area 105 in order to maintain the recording order. That is, the ROM areas 121 and 122 are included in the area portion excluded from the data area 115 in order to maintain the recording order, even though the area may be included in the data area 115 where data can be originally recorded. Can be arranged. In other words, it is not necessary to provide ROM areas 121 and 122 in the data areas 105 and 115 again. As a result, ROM areas 121 and 122 can be arranged on the optical disk 100 without reducing the capacity of the area portion where the user can freely record data (that is, the data areas 105 and 115) as much as possible.

[0079] (3) Other specific area configurations

Next, another specific area configuration will be described with reference to FIGS. FIGS. 9 to 11 are data configuration diagrams conceptually showing other specific area configurations on the optical disc 100, respectively.

[0080] As shown in FIG. 9, it is not necessary to record the entire ROM areas 121 and 122 and necessary data including management data and control data that are referred to when recording and reproducing data. . More specifically, necessary data is recorded in a part of the ROM areas 121 and 122, and the other part of the ROM data areas 121 and 122 is used for recording and playback. Dummy data (for example, 00h data etc.) may be recorded.

As a result, even when the amount of data to be recorded in the ROM areas 121 and 122 is small, the ROM areas 121 and 122 having a certain size can be secured.

[0082] As shown in FIG. 10, the ROM areas 121 and 122 may be smaller than the sum of the relative tolerance and the clearance. Here, the size of the ROM area 121 is “N1”, and the size of the ROM area 122 is “Ml”. Furthermore, the address at the outer edge of ROM area 122 is the data. It is assumed that there is an interpolation relationship with the address of the outer edge of the area 105.

In this case, the address of the end portion on the outer peripheral side of the ROM area 122 is “X-bar”. Further, the address of the end portion on the inner peripheral side of the ROM area 122 is “X-bar-Ml”. In addition, the address of the area portion of the L1 layer facing the outer edge of the data area 105 is “X_bar + Ofs (X) —Ml”.

On the other hand, the address of the area portion of the L1 layer facing the inner peripheral end of the data area 105 is “A−bar−Ml + Ofs (X)”. Further, the address of the outer edge of the ROM area 121 is “A−bar + Ofs (A) −Ml + Ofs (X)”. Further, the address of the inner peripheral end of the ROM area 121 is “A_bar + Ofs (A) —Ml + Ofs (X) —N1”. Further, the area portion of the L1 layer where the address is “A-bar” is located further on the inner peripheral side than the inner peripheral end of the data area 105 where the address is “A”.

[0085] As shown in FIG. 11, the ROM areas 121 and 122 may be larger than the sum of the relative tolerance and the clearance. Here, the size of the ROM area 121 is “N2,” and the size of the ROM area 122 is “M2.” Further, the address of the outer edge of the ROM area 122 is the outer edge of the data area 105. It is assumed that there is an interpolation relationship with the part address.

In this case, the address of the end portion on the outer peripheral side of the ROM area 122 is “X-bar”. The address of the end portion on the inner peripheral side of the ROM area 122 is “X-bar-M2”. Further, the address of the area portion of the L1 layer facing the outer edge of the data area 105 is “X_bar + Ofs (X) —M2”.

On the other hand, the address of the area portion of the L1 layer facing the inner peripheral end of the data area 105 is “8-1) & 1: -1 ^ 2 + 0 £ 5 ()”. Further, the address of the outer peripheral end of the ROM area 121 is “A—bar + Ofs (A) —1 ^ 2 + 0 £ 5 ()”. Further, the address of the inner peripheral end of the ROM area 121 is “A_bar + Ofs (A) —M2 + Ofs (X) —N2”. In addition, the area portion of the L1 layer where the address is “A-bar” is located further on the outer peripheral side than the end portion on the inner peripheral side of the data area 105 where the address is “A”.

As shown in FIGS. 10 and 11, the addresses of the data areas 105 and 115 and the ROM areas 121 and 122 are represented by the same mathematical formula regardless of the sizes of the ROM areas 121 and 122. This is the case when the size of ROM area 121 or 122 is 0 (ie M The same applies if 1 = 0, M2 = 0, N1 = 0 or N2 = 0). For this reason, while the sizes of the ROM areas 121 and 122 can be arbitrarily set, the address assignment can be performed relatively easily.

As a specific example of the “pre-recording area”, the “pre-recording area” can be formed by actual recording before shipping the disc described for the ROM area. In that case, the recording order cannot be maintained because the L0 layer is unrecorded! /, But it is possible to set the recording power on the assumption that the L0 layer is unrecorded and record. Thereby, the “pre-recording area” of the L1 layer can be suitably formed.

In the above-described embodiment, the optical disc 100 has been described as an example of the recording medium. However, the present invention is not limited to the optical disc and its recorder, and other high-density recording or various recordings corresponding to a high transfer rate. It can also be applied to media.

[0091] The present invention is not limited to the above-described embodiments, but can be modified as appropriate without departing from the spirit or idea of the invention which can be read. Recording media are also included in the technical scope of the present invention. Industrial applicability

The recording medium according to the present invention can be used for a recording medium such as a DVD.

Claims

The scope of the claims

[1] a first recording layer including a first area and a second recording layer including a second area;

The one end of the second area is located at a position shifted to the other side different from the one end than the one end of the first area;

A recording medium, wherein a pre-recording area in which recording information is recorded in advance is disposed adjacent to one end of the second area.

[2] The one end of the second area is at a predetermined position at least in each of the first recording layer and the second recording layer to the other side of the one end of the first area. 2. The recording medium according to claim 1, wherein the recording medium is located at a position shifted by a tolerance length indicating a sum of an allowable range of positional deviation from the predetermined position of the address to be defined in the above.

[3] In addition to the tolerance length, (0) the end of the second area on one side is (0) the laser beam for recording the recording information on the recording medium is focused on the second recording layer. An allowable maximum value of the spot radius of the laser beam on the first recording layer, and (ii) an allowable maximum of relative eccentric deviation between the first recording layer and the second recording layer. From the sum of the values, (iii) at least part of the laser beam irradiated for recording the recording information on the second recording layer records the recording information! When the second recording layer is allowed to be irradiated through the area portion of the recording layer, an allowable maximum value of the size of the area portion of the first recording layer where the recording information is not recorded is set. It is located at a position shifted by the pulled clearance length. Recording medium described in item 2.

[4] The other end of the second area is located at a position shifted to one side with respect to the other end of the first area.

The recording medium according to claim 1, wherein the pre-recording area is arranged adjacent to an end portion on the other side of the second area.

[5] The other end of the second area is located at a predetermined position at least in each of the first recording layer and the second recording layer to one side of the other end of the first area. 5. The recording medium according to claim 4, wherein the recording medium is located at a position shifted by a tolerance length indicating a sum of an allowable range of positional deviation from the predetermined position of the address to be defined in the above.

[6] In addition to the tolerance length, (0) the laser beam for recording the recording information on the recording medium is focused on the second recording layer in addition to the tolerance length. An allowable maximum value of the spot radius of the laser beam on the first recording layer, and (ii) an allowable maximum of relative eccentric deviation between the first recording layer and the second recording layer. From the sum of the values, (m) at least part of the laser beam irradiated to record the recording information on the second recording layer is recorded on the recording information! When the second recording layer is allowed to be irradiated through the area portion of the recording layer, an allowable maximum value of the size of the area portion of the first recording layer where the recording information is not recorded is set. It is located at a position shifted by the pulled clearance length. Serial mounting of the recording medium.

7. The recording medium according to claim 1, wherein dummy information is recorded in advance in the pre-recording area in addition to the recording information.

8. The recording medium according to claim 2, wherein the tolerance length is 40 μm in the radial direction of the recording medium.

[9] The recording medium according to claim 3, wherein the clearance length is 65 μm in the radial direction of the recording medium.

[10] The recording information is recorded on the first recording layer toward the one side or the other side, and the recording information is recorded on the first recording layer in the second recording layer. 2. The recording medium according to claim 1, wherein the recording information is recorded toward a side different from a side on which is recorded.