JP2006209915A - Recording apparatus and recording method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform appropriately tracking processing using a three beams tracking system for a multi-layer disk having a plurality of recording layers in which data recording directions are different with each other. <P>SOLUTION: The apparatus is provided with: a recording means (11) recording data by irradiating a recording medium (100) in which a first recording layer (L0) recording data toward one direction and a second recording layer (L1) recording data toward the other direction are layered with a light beam (B); a diffraction means (12) arranged between the recording means and the recording medium and generating a main beam and a plurality of sub-beams by diffracting the light beam; a selecting means (60) selecting at least two sub-beams out of the plurality of sub-beams; and a tracking means (44) performing tracking processing by a tracking signal generated from the selected sub-beams. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technical field of a recording apparatus and method such as a DVD recorder, and a computer program that causes a computer to function as such a recording apparatus.

  Conventionally, optical discs capable of writing data such as DVD ± R or DVD ± RW have a plurality of recording layers in addition to a single-layer optical disc in which only one recording layer for recording recording data is formed. Multi-layer optical discs exist. For example, what is currently commercialized includes a single-sided single-layer DVD having only one recording layer, and a single-sided dual-layer DVD having two recording layers on one side. This single-sided single layer DVD has a maximum recording capacity of about 4.7 GB, whereas a single-sided double-layered DVD has a maximum recording capacity of about 8.5 GB. Thus, the maximum recording capacity of the optical disc increases as the recording layer increases.

  On the other hand, when data is recorded on a single-layer optical disk, a semiconductor laser tracking process (tracking control) is performed. As a specific example of the tracking process, there is a three-beam tracking system described in Non-Patent Document 1. The three-beam tracking method generates a main beam mainly used for data recording and two sub-beams mainly used for tracking processing by making a light beam irradiated from an optical pickup incident on a diffraction grating, This is a technique for performing tracking processing using these sub-beams. On the recording surface of a single-layer optical disc, the spots of the two sub beams are shifted by half the track pitch compared to the spot of the main beam, and the reflected light of the two sub beams is received by, for example, a two-divided photodetector. Tracking processing is performed by detecting the difference in the amount of light (or phase) obtained by doing so.

“Optical Head for Magneto-Optical Disk”, Electronic Materials, Industrial Research Committee, issued July 1, 1988, Vol. 27, No. 7, p. 73-74

  However, a multilayer optical disc having a plurality of recording layers has a technical problem that the tracking process using the above-described three-beam tracking method cannot be suitably executed. Specifically, in a multilayer optical disc having a plurality of recording layers, the recording direction of data may be different for each recording layer. Therefore, the three-beam tracking method in a single-layer optical disc having a single recording layer is used. There is a technical problem that it cannot be used as it is. The same problem occurs when three or more sub-beams are used.

Further, even in a single-layer optical disc, the technical problems described above become an obstacle to a suitable tracking process if there are various data recording modes on the single-layer optical disc. That is, in the case of a single-layer optical disc in which data is recorded in a mode other than the recording mode originally intended by the three-beam tracking method, the above-described technical problem becomes an obstacle to a suitable tracking process. Examples of problems to be solved include the above. It is an object of the present invention to provide a recording apparatus and method, and a computer program capable of suitably performing tracking processing using a plurality of light beams on recording media having different data recording modes. .

  In order to solve the above-described problem, the recording apparatus according to claim 1 is disposed between a recording unit that records data by irradiating a recording medium with a light beam, the recording unit, and the recording medium. Diffracting means for diffracting the light beam to generate the main beam used for recording the data and performing tracking processing, and a plurality of sub beams used for performing the tracking processing; Selection means for selecting at least two sub-beams out of the sub-beams, and tracking means for executing the tracking process by a tracking signal generated from the main beam and the selected at least two sub-beams.

  In order to solve the above-described problem, the recording apparatus according to claim 9 irradiates a recording medium on which a concentric or spiral recording track for recording data is formed with a light beam. A recording means for recording data, a main beam disposed between the recording means and the recording medium and used for recording the data by diffracting the light beam and for performing a tracking process; Diffraction means for generating at least two sub-beams used for performing the tracking process and having at least one recording track positioned between the main beam and the reflected light of the main beam and the at least two sub-beams Tracking means for executing the tracking process according to the tracking signal Obtain.

  In order to solve the above problem, the recording method according to claim 12 is arranged between a recording unit that records data by irradiating a recording medium with a light beam, and between the recording unit and the recording medium, A recording apparatus comprising: a main beam used for recording the data by diffracting the light beam and performing a tracking process; and a diffractive means for generating a plurality of sub beams used for performing the tracking process. The recording method according to claim 1, wherein a selection step of selecting at least two sub-beams among the plurality of sub-beams, and tracking for executing the tracking processing by a tracking signal generated from the main beam and the at least two selected sub-beams. A process.

  In order to solve the above problem, the recording method according to claim 13 is characterized in that the recording medium on which concentric or spiral recording tracks for recording data are irradiated with a light beam to irradiate the recording medium. A recording means for recording data, a main beam disposed between the recording means and the recording medium and used for recording the data by diffracting the light beam and for performing a tracking process; A recording method in a recording apparatus, comprising: diffractive means for generating at least two sub-beams that are used to perform the tracking process and in which at least one recording track is located between the main beam and the main beam; A control step of controlling the recording means to irradiate, the main beam and the at least two The tracking signal generated from the reflected light of Bubimu and a tracking step of executing the tracking process.

  In order to solve the above problem, a computer program according to claim 14 is a computer program for recording control for controlling a computer provided in the recording apparatus according to any one of claims 1 to 8. The computer is caused to function as at least a part of the selection unit and the tracking unit.

  In order to solve the above problem, a computer program according to claim 15 is a computer program for recording control for controlling a computer provided in the recording apparatus according to any one of claims 9 to 11. , Causing the computer to function as the tracking means.

  The operation and other advantages of the present invention will become apparent from the embodiments described below.

  Hereinafter, description will be given of embodiments of the recording apparatus and the recording method and the computer program of the present invention.

(Embodiment of recording apparatus)
According to a first embodiment of the recording apparatus of the present invention, a recording unit that records data by irradiating a recording medium with a light beam, the recording unit is disposed between the recording unit and the recording medium, and the light beam is Diffracting means for generating a plurality of sub-beams used for recording the data by performing diffraction and performing tracking processing, and a plurality of sub-beams used for performing the tracking processing, and at least two of the plurality of sub-beams Selecting means for selecting one sub-beam, and tracking means for executing the tracking process by a tracking signal generated from the main beam and the selected at least two sub-beams.

  According to the first embodiment of the recording apparatus of the present invention, a light beam is irradiated onto a recording medium such as an optical disk by the operation of the recording means. As a result, data can be recorded on the recording medium.

  Particularly in the first embodiment, a diffractive means is disposed between the recording means and the recording medium. The light beam emitted from the recording means is incident on the diffracting means and then condensed on a recording medium (specifically, for example, a recording layer for which data recording is desired). The diffracting means diffracts the light beam emitted from the recording means, so that a main beam used mainly for tracking processing during data recording and recording operations and a plurality of tracking beams used mainly during tracking processing during recording operations are used. Generate a sub-beam. As a result, data is recorded by focusing the main beam on the recording medium.

  On the other hand, at least two sub-beams used for performing tracking processing are selected from among the plurality of sub-beams by the operation of the selection means. That is, in this embodiment, the tracking process is performed by irradiating the recording medium with the main beam and a plurality of sub beams. The “tracking signal” here has a broad meaning indicating a signal obtained from each of the main beam and the plurality of sub beams or at least one reflected light in order to perform tracking processing. At this time, there is a sub-beam that can perform a suitable tracking process depending on the type of recording medium, the configuration and state of the recording layer that is the target of the recording operation, and the data recording mode such as the direction of data recording. It is selected appropriately. A tracking signal for controlling the tracking process is generated from the reflected light of the main beam and the at least two sub beams selected by the selection means. After that, tracking processing is performed by using the tracking signal generated from the reflected light of the main beam and at least two sub beams selected by the selection unit by the operation of the tracking unit.

  In general, when tracking processing is performed using a plurality of light beams in each recording medium, the mode or state of the recording area where the sub beam is condensed when data is recorded on one recording medium, and other recording There may be a case where the mode or state of the recording area where the sub beam is condensed when data is recorded on the medium is different. This will be described in detail with reference to the drawings in the embodiments to be described later, but is caused by the fact that the recording direction of data is different (specifically, reversed) for each recording medium. . At this time, tracking signals obtained in the respective recording media may be different. Specifically, for example, even if a suitable tracking signal is obtained on one recording medium, a suitable tracking signal may not be obtained on the other recording medium. However, in this embodiment, at least two sub beams are selected such that a plurality of sub beams are irradiated onto the recording medium and a suitable tracking process can be performed on each recording medium. Since the tracking signal is generated using the selected sub beam, the tracking process can be performed on each recording medium without causing any particular inconvenience.

  As a result, according to the recording apparatus according to the first embodiment, tracking processing using a plurality of light beams can be appropriately performed on recording media having different data recording modes.

  According to one aspect of the first embodiment of the recording apparatus of the present invention, the selection unit selects the at least two sub beams according to the recording direction of the data on the recording medium.

  According to this aspect, it is possible to change which sub-beam is selected for each recording medium in consideration of the difference in the data recording direction. Accordingly, tracking processing using a plurality of light beams can be performed on recording media having different data recording modes (particularly, data recording directions and the like).

  In another aspect of the first embodiment of the recording apparatus of the present invention, the recording medium records data in one direction (for example, the direction from the inner circumference side to the outer circumference side of the recording medium). A second recording layer for recording the data in a different direction (for example, a direction from the outer peripheral side to the inner peripheral side of the recording medium) different from the one direction, and the recording unit includes: The data is recorded on the recording medium by irradiating a light beam so as to be focused on the first recording layer or the second recording layer.

  According to this aspect, the light beam is irradiated to the recording layer for which data recording is desired, of the first recording layer and the second recording layer. When recording data on the first recording layer, the light beam is condensed on the first recording layer, and when recording data on the second recording layer, the light beam is condensed on the second recording layer. . As a result, data can be recorded on each of the first recording layer and the second recording layer.

  In this mode, the data is recorded on either the first recording layer or the second recording layer, or the data recording mode of each of the first recording layer and the second recording layer (particularly, the data recording mode). Depending on the direction and the like, it is possible to change which sub-beam is selected for each recording medium. Accordingly, it is possible to appropriately perform tracking processing using a plurality of light beams on a multilayer recording medium having a plurality of recording layers having different data recording directions.

  As described above, in the aspect of the recording apparatus that records data on the recording medium including the first recording layer and the second recording layer, the selection unit includes the light beam on either the first recording layer or the second recording layer. The at least two sub-beams may be selected from the plurality of sub-beams depending on whether they are condensed.

  According to this configuration, the sub beam to be selected is appropriately determined in consideration of the difference in the data recording mode for each recording layer. Accordingly, the tracking process can be suitably performed in each of the plurality of recording layers having different data recording directions.

  In another aspect of the first embodiment of the recording apparatus of the present invention, a concentric or spiral recording track for recording the data is formed on the recording medium, and the selection means includes: At least two sub-beams, one sub-beam in which the recording track on which the data has been recorded is arranged at both ends of the spot to be condensed (that is, formed by condensing), and the focused spot And other sub-beams in which recording tracks on which the data is not recorded are arranged at both end portions.

  According to this aspect, the recording aspects of the both end portions of each spot of at least two sub-beams selected by the selection means are substantially the same. Specifically, for example, in the selected spot of one sub beam, a recording track on which data has been recorded is located on each of one side and the other side with respect to the traveling direction of the main beam, For example, in the selected spot of the other sub beam, a recording track on which data is not recorded is located on one side and the other side with respect to the traveling direction of the main beam. In other words, in each selected sub-beam, recording tracks having different recording modes are not arranged at both end portions. For this reason, for example, when the reflected light of the sub beam is received by a light receiving element having two light receiving parts divided along the traveling direction of the main beam, the amount of reflected light in each light receiving part is substantially the same. Therefore, a suitable tracking process can be performed as will be described later.

  In another aspect of the first embodiment of the recording apparatus of the present invention, a concentric or spiral recording track for recording the data is formed on the recording medium. i) between the main track that is the recording track on which the main beam is focused and each of the two first adjacent tracks that are the recording tracks adjacent to the main track; and (ii) the first adjacent track. And the plurality of sub-beams collected at substantially the center between each of the two second adjacent tracks which are the recording tracks adjacent to the first adjacent track.

  According to this aspect, a total of four sub-beams are collected, one between the main track and each of the two first adjacent tracks and one between each of the first adjacent track and the second adjacent track. Is done. Therefore, as will be described in detail in the following embodiments, the mode or state of the recording area where the sub-beam is condensed when data is recorded on one recording medium (or the first recording layer), and the other Even when the mode or state of the recording area where the sub-beam is condensed when data is recorded on the recording medium (or the second recording layer), a suitable tracking process can be performed.

  In another aspect of the first embodiment of the recording apparatus of the present invention, a concentric or spiral recording track for recording the data is formed on the recording medium. It is substantially the center between the main track, which is the recording track on which the main beam is condensed, and each of the two adjacent tracks, which are the recording tracks adjacent to the main track, and the main beam is condensed. The plurality of sub-beams that are focused in the traveling direction of the main beam and in the direction opposite to the traveling direction are generated.

  According to this aspect, between the main track and the two first adjacent tracks, one on the traveling direction side of the main beam and the traveling direction of the main beam with respect to the position where the main beam is focused. A total of four sub-beams are collected, one on the opposite direction side. That is, a plurality of sub beams are condensed so as to draw X on the recording surface. Therefore, as will be described in detail in the following embodiments, the mode or state of the recording area where the sub-beam is condensed when data is recorded on one recording medium (or the first recording layer), and the other Even if the mode or state of the recording area where the sub-beam is condensed when data is recorded on the tail of the recording medium (or the second recording layer), a suitable tracking process can be performed.

  In another aspect of the first embodiment of the recording apparatus of the present invention, the diffraction means is controlled so that the recording medium is selectively irradiated with the at least two selected sub-beams among the plurality of sub-beams. And a control means.

  According to this aspect, it is not necessary to irradiate the sub beam not selected by the selection unit from the recording unit. Therefore, the load on the recording apparatus can be reduced.

  In a second embodiment of the recording apparatus of the present invention, recording is performed by recording the data by irradiating a recording medium provided with concentric or spiral recording tracks for recording data. And a main beam disposed between the recording means and the recording medium and used for recording the data and performing tracking processing by diffracting the light beam and performing the tracking processing A diffractive means for generating at least two sub-beams, wherein at least one recording track is located between the main beam and a tracking signal generated from reflected light of the main beam and the at least two sub-beams. Tracking means for executing the tracking process.

  According to the second embodiment of the recording apparatus of the present invention, similarly to the recording apparatus according to the first embodiment described above, data can be recorded on the recording medium on which the recording track is formed by the operation of the recording means. it can. In addition, a main beam and at least two sub beams are generated in the diffractive unit on which the light beam emitted from the recording unit is incident.

  Particularly in the second embodiment, at least one recording track is disposed between each of the at least two sub beams and the main beam. For example, as described later, in a recording medium in which a groove track and a land track are formed and data is recorded on the groove track, at least one groove track is disposed between the main beam and the sub beam. . By generating such a sub-beam, a suitable tracking process can be performed as will be described in detail in a later embodiment. That is, the mode or state of the recording area where the sub beam is condensed when data is recorded on one recording medium, and the recording area where the sub beam is condensed when data is recorded on another recording medium Even if the mode or state is different, suitable tracking processing can be performed.

  As a result, according to the recording apparatus according to the second embodiment, tracking processing using a plurality of light beams can be appropriately performed on recording media having different data recording modes.

  According to one aspect of the second embodiment of the recording apparatus of the present invention, the recording medium has a first recording layer for recording data in one direction and another direction different from the one direction. A second recording layer for recording the data is laminated, and the recording means irradiates a light beam so as to focus the light on the first recording layer or the second recording layer, whereby the recording medium is Record the data.

  According to this aspect, it is possible to appropriately perform tracking processing using a plurality of light beams on a multilayer recording medium having a plurality of recording layers having different data recording directions.

  According to another aspect of the second embodiment of the recording apparatus of the present invention, the diffracting means is provided at both end portions of a spot to be condensed (that is, formed by condensing) as the at least two sub beams. One sub beam in which the recording track on which the data has been recorded is arranged, and another sub beam in which a recording track on which the data is not recorded are arranged at both ends of the focused spot are generated.

  According to this aspect, the recording aspects of both end portions of the spot formed by each of the at least two sub-beams are substantially the same. Specifically, for example, in a spot formed by one sub beam, a recording track on which data has been recorded is located on one side and the other side with respect to the traveling direction of the main beam, and the other, for example, another In the spot formed by the sub beam, a recording track on which no data is recorded is located on one side and the other side with respect to the traveling direction of the main beam. In other words, in each selected sub-beam, recording tracks having different recording modes are not arranged at both end portions. For this reason, for example, when the reflected light of the sub beam is received by a light receiving element having two light receiving parts divided along the traveling direction of the main beam, the amount of reflected light in each light receiving part is substantially the same. Therefore, a suitable tracking process can be performed as will be described later.

(Embodiment of recording method)
According to a first embodiment of the recording method of the present invention, a recording means for recording data by irradiating a recording medium with a light beam, a recording means disposed between the recording means and the recording medium, and the light beam A recording method in a recording apparatus, comprising: a main beam used for recording the data by diffracting and performing a tracking process; and a diffraction means for generating a plurality of sub-beams used for performing the tracking process. A selection step of selecting at least two sub-beams among the plurality of sub-beams, and a tracking step of executing the tracking process by a tracking signal generated from the main beam and the at least two selected sub-beams.

  According to the embodiment of the recording method of the present invention, it is possible to receive the same benefits as the various benefits of the first embodiment of the recording apparatus of the present invention described above.

  Incidentally, in response to the various aspects of the first embodiment of the recording apparatus of the present invention described above, the first embodiment of the recording method of the present invention can also adopt various aspects.

  In the second embodiment of the recording method of the present invention, the recording is performed by irradiating a recording medium on which a concentric or spiral recording track for recording data is irradiated with a light beam. And a main beam disposed between the recording means and the recording medium and used for recording the data and performing tracking processing by diffracting the light beam and performing the tracking processing And a diffractive means for generating at least two sub-beams in which at least one recording track is located between the main beam and the main beam. A control step for controlling the recording means, and reflected light of the main beam and the at least two sub-beams; The tracking signal generated Ri and a tracking step of executing the tracking process.

  According to the embodiment of the recording method of the present invention, it is possible to receive the same benefits as the various benefits of the second embodiment of the recording apparatus of the present invention described above.

  Incidentally, in response to the various aspects in the second embodiment of the recording apparatus of the present invention described above, the second embodiment of the recording method of the present invention can also adopt various aspects.

(Embodiment of computer program)
The first embodiment relating to the computer program of the present invention is a computer program for recording control for controlling a computer provided in the above-described first embodiment (including various aspects thereof) relating to the recording apparatus of the present invention. The computer is caused to function as at least a part of the selection unit and the tracking unit. The second embodiment according to the computer program of the present invention is a recording control computer for controlling the computer provided in the above-described second embodiment (including various aspects thereof) according to the recording apparatus of the present invention. A program that causes the computer to function as at least part of the tracking means.

  According to each embodiment relating to the computer program of the present invention, if the computer program is read from a recording medium such as a ROM, a CD-ROM, a DVD-ROM, and a hard disk for storing the computer program, and executed by the computer, Alternatively, if the computer program is executed after being downloaded to a computer via communication means, the above-described embodiment of the recording apparatus of the present invention can be realized relatively easily.

  Incidentally, in response to the various aspects of the first or second embodiment of the recording apparatus of the present invention described above, the first or second embodiment of the computer program of the present invention can also adopt various aspects. .

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

  As described above, the first embodiment of the recording apparatus or method of the present invention includes a recording unit, a diffraction unit, a selection unit and a tracking unit, or a selection step and a tracking step. The second embodiment according to the recording apparatus or method of the present invention includes a recording unit, a diffraction unit and a tracking unit, or a control step and a tracking step. Accordingly, it is possible to appropriately perform tracking processing using the three-beam tracking method on recording media having different data recording modes.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Configuration of optical disc)
First, the configuration of an optical disc 100 on which data is recorded and the recorded data is reproduced by the recording / reproducing apparatus according to the present embodiment will be described with reference to FIGS. FIG. 1 is a plan view and a cross-sectional view showing a schematic configuration of the two-layer optical disc 100, and FIG. 2 is a partially enlarged perspective view of the recording surface of the optical disc 100. As shown in FIG.

  As shown in FIG. 1A, the optical disc 100 has a disk shape with a diameter of about 12 cm, and a center hole 102 is provided at the center. Examples of the optical disc 100 include DVD ± R, DVD ± RW, DVD-RAM, BD (Blu-ray Disc), HD DVD (High Definition DVD), and the like. As shown in FIG. 1B, the optical disc 100 has a structure in which a first recording layer L0 and a second recording layer L1 are laminated between transparent substrates 101a and 101b. Specifically, a dielectric layer, a reflective film, an adhesive layer, and the like (not shown) are formed between the first recording layer L0 and the second recording layer L1. In addition, tracks such as a groove track and a land track (not shown) are alternately provided in each recording area of the first recording layer L0 and the second recording layer L1 in a spiral shape or concentric shape with the center hole 102 as a center. . Data is divided and recorded in units of ECC blocks on each of the groove track and the land track.

  In particular, in this embodiment, the optical disc 100 employs an opposite track path method. That is, in the first recording layer L0, data is recorded from the inner circumference side to the outer circumference side of the optical disc 100, while on the other hand, in the second recording layer L1, the first recording layer L0 is opposite to the first recording layer L0. Data is recorded from the outer peripheral side toward the inner peripheral side.

  The configuration of the optical disc 100 will be described in more detail. As shown in FIG. 2, the optical disc 100 is placed on the disc-shaped transparent substrate 101a (on the lower side in FIG. 2) and is not heated by the heating that constitutes the data recording surface. A reversible change recording type or phase change recording type first recording film 117 is laminated, and a transflective film 118 is laminated thereon (on the lower side in FIG. 2). Further, a second recording film 127 is laminated on the first recording film 117. Specifically, the adhesive layer 115 is formed on the transflective film 118, the second recording film 127 is laminated on the adhesive layer 115, and the reflective film 128 is laminated on the second recording film 127. Finally, the transparent substrate 101b is laminated. Groove tracks GT and land tracks LT are alternately formed on the data recording surface composed of the surfaces of the first recording film 117 and the second recording film 127. Incidentally, at the time of recording and reproduction of the optical disc 100, for example, as shown in FIG. 2, the light beam B is irradiated onto, for example, the groove track GT through the transparent substrate 101a. For example, at the time of recording, the light beam B is irradiated with the recording laser power, so that irreversible change recording or phase change due to heating to the first recording film 117 or the second recording film 127 according to the data to be recorded. Recording is performed. On the other hand, at the time of reproduction, reading of data recorded on the first recording film 117 and the second recording film 127 is performed by irradiating the light beam B with a reproduction laser power weaker than the recording laser power.

  The groove track GT is oscillated with a constant amplitude and spatial frequency. That is, the groove track GT is wobbled, and the cycle of the wobble 119 is set to a predetermined value. On the land track LT, address pits called land prepits LPP indicating preformat addresses are formed. By these two addressing (namely, wobble 119 and land prepit LPP), it is possible to obtain information necessary for data recording such as disk rotation control during recording, generation of a recording clock, and recording address. Note that information necessary for data recording such as a preformat address may be recorded in advance by modulating the wobble 119 of the groove track GT by a predetermined modulation method such as frequency modulation or phase modulation.

(First embodiment of recording / reproducing apparatus)
Next, the recording / reproducing apparatus 1 as a first embodiment of the recording apparatus of the present invention will be described with reference to FIGS.

(1) Basic Configuration First, the configuration of the recording / reproducing apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 3 is a block diagram conceptually showing the basic structure of the recording / reproducing apparatus 1 in the first example.

  As shown in FIG. 3, the recording / reproducing apparatus 1 includes an optical pickup 10, a signal processing unit 21, a laser driving circuit 22, a reproducing unit 30, a three-beam tracking servo circuit 41, a tracking driving circuit 44, and a focus. A servo circuit 51, a focus drive circuit 52, a control unit 60, and a spindle motor 70 are provided. The recording / reproducing apparatus 1 is an apparatus for recording data by irradiating the optical disc 100 with the light beam B and reproducing the data recorded on the optical disc 100. Note that the recording / reproducing apparatus 1 according to the present embodiment performs processing on the two-layer type optical disc 100 in which the first recording layer L0 and the second recording layer L1 are formed as shown in FIGS. Do.

  The optical pip-up 10 includes a hologram laser 11, a grating element 12, a condenser lens 13, an objective lens 14, and an actuator unit 15 that holds the objective lens 14.

  The hologram laser 11 constitutes one specific example of the “recording means” in the present invention, and has a laser chip, a substrate, a light receiving element, a hologram element, etc. (not shown). The laser chip and the light receiving element are arranged on the same substrate, and the hologram element is provided facing the output side of the light beam B of the substrate. The laser chip emits a light beam B, and the light receiving element receives the input light beam B. The hologram element transmits the light beam B output from the laser chip as it is and refracts the light beam incident from the surface opposite to the incident surface of the light beam B so as to be condensed on the light receiving element on the substrate. Let Thus, the hologram laser 11 functions as a light source and a detector.

  In the present embodiment, a three-beam tracking method is used to perform tracking processing (tracking control). Therefore, a light receiving element that receives the reflected light of the light beam B (more specifically, each of a plurality of light receiving elements corresponding to a main beam and a sub beam, which will be described later), for example, is divided into two parts (or 4 divisions). For example, the light receiving element includes a light receiving unit D1 that receives reflected light in the left half of the light beam B and a light receiving unit D2 that receives reflected light in the right half with respect to the traveling direction of the light beam B on the optical disc 100. is doing. From the light receiving element having the light receiving portions D1 and D2 divided in this way, a sum signal that is a sum of signals obtained in the respective light receiving portions, a difference signal that is a difference, or a push-pull signal is output as a light receiving signal S31. The

  The grating element 12 constitutes one specific example of the “diffractive means” in the present invention, and diffracts the light beam B emitted from the hologram laser 11 to mainly record data and perform a tracking process. And two sub-beams mainly for performing tracking processing. The grating element 12 may be configured to include a transparent substrate having a large number of slits (or grooves), or may be configured to include a liquid crystal slit including a liquid crystal element.

  In the following description, when the light beam B is simply expressed, the light beam B itself emitted from the hologram laser 11 is shown, and the main beam and two sub beams generated in the grating element 12 are shown. Note that this may indicate.

  The condenser lens 13 makes the incident light beam B substantially parallel light and makes it incident on the objective lens 14. More specifically, each of the main beam and the two sub beams generated in the grating element 12 is made substantially parallel light and incident on the objective lens 14.

  The objective lens 14 is provided in the actuator unit 15. The actuator unit 15 has a drive mechanism for changing the arrangement position of the objective lens 14. The actuator unit 15 moves the position of the objective lens 14 in the tracking direction in accordance with the actuator drive signal S44 supplied from the tracking drive circuit 44. In this way, tracking processing (tracking control) is performed.

  The actuator unit 15 moves the position of the objective lens 14 in the focus direction in accordance with the actuator drive signal S52 supplied from the focus drive circuit 52. In this way, focus processing (focus control) is performed. In particular, when data is recorded on the first recording layer L0, focus processing is performed so that the light beam B is focused on the first recording layer L0, while when data is recorded on the second recording layer L1. Is focused so that the light beam B is focused on the second recording layer L1.

  The objective lens 14 is incident with the light beam B that has been made substantially parallel by the condenser lens 13. The objective lens 14 collects these light beams B and irradiates the optical disc 100 with them.

  The signal processing unit 21 has an input terminal IN, and performs signal processing on data input from the outside via the input terminal IN based on a control signal supplied from the control unit 60 via a control line (not shown). Is output to the laser drive circuit 22 as a recording signal S21. More specifically, the signal processing unit 21 adds an address, a parity, a correction code (ECC) or a sync frame (synchronization frame) to the data input from the outside, or scrambles the data. The recording signal S21 is generated by performing various modulation such as 8/16 modulation.

  The laser drive circuit 22 is mainly composed of an amplifier circuit, generates a laser drive signal S22 by amplifying the recording signal S21 input from the signal processing unit 21 and supplies the laser drive signal S22 to the hologram laser 11 of the optical pickup 10. To do. The amplification factor in the laser drive circuit 22 is controlled by the signal processing unit 21. When data is recorded on the optical disc 100, the amount of energy that can cause a phase change or a thermal change from the hologram laser 11 to the optical disc 100 (hereinafter, referred to as the following) The amplification factor is controlled so that a light beam B of “recording power” is output. On the other hand, when data recorded on the optical disc 100 is reproduced, a light beam B having an energy amount (hereinafter referred to as “reproduction power”) that does not cause a phase change or heat change in the optical disc 100 is output from the hologram laser 11. The amplification factor is controlled.

  The reproduction unit 30 has an output terminal OUT, and reproduces data corresponding to the light reception signal S31 supplied from the hologram laser 11 based on a control signal supplied from the control unit 60 via a control line (not shown). Output to the output terminal OUT. The light reception signal S31 is a signal indicating the amount of light received for each light receiving element, which is obtained by receiving the reflected light of the light beam B received by the hologram laser 11 with a plurality of light receiving elements. In particular, in this embodiment, the reflected light of the light beam B is received by the light receiving elements corresponding to the main beam and the two sub beams, and the received light signal S31 corresponding to the main beam and the two sub beams is obtained. .

  The three-beam tracking servo circuit 41 generates a tracking servo control signal (tracking error signal) S41 based on the light reception signal S31 output from the hologram laser 11. More specifically, the tracking servo control signal S41 is generated by subtracting the push-pull signals of the two sub beams from the push-pull signal of the main beam. Thereafter, the three-beam tracking servo circuit 41 supplies a tracking servo control signal S41 to the tracking drive circuit 44. The three-beam tracking system is the same as the above-described prior art or other conventional techniques except for the features of the present invention, and thus the basic description thereof is omitted.

  The tracking drive circuit 44 constitutes a specific example of the “tracking means” of the present invention together with the control unit 60, and the actuator drive signal S 44 is based on the tracking servo control signal S 41 supplied from the three-beam tracking servo circuit 41. And the actuator unit 15 is driven. That is, the tracking drive circuit 44 controls the actuator unit 15 by supplying the actuator drive signal S44, and adjusts the position of the objective lens 14 in the radial direction (that is, the tracking direction) of the optical disc 100.

  The focus servo circuit 51 generates a focus servo control signal (focus error signal) S51 based on the light reception signal S31 output from the hologram laser 11. Thereafter, the focus servo circuit 51 supplies the generated focus servo control signal S51 to the focus drive circuit 52.

  The focus drive circuit 52 generates an actuator drive signal S52 based on the focus servo control signal S51 supplied from the focus servo circuit 51, and drives the actuator unit 15. That is, the focus drive circuit 52 controls the actuator unit 15 by supplying the actuator drive signal S52, and adjusts the distance of the objective lens 14 to the optical disc 100 (ie, the position in the focus direction).

  The control unit 60 is mainly configured by a CPU (Central Processing Unit), and controls the entire recording / reproducing apparatus 1 by outputting control signals to the various components described above via control lines (not shown).

  The spindle motor 70 is configured to rotate the optical disc 100 at a predetermined speed based on a spindle servo control signal generated from the light reception signal S31 output from the hologram laser 11.

(2) Operation Principle Next, with reference to FIG. 4, the operation principle (particularly the recording operation) of the recording / reproducing apparatus 1 in the first example will be described. FIG. 4 is a flowchart conceptually showing a flow of the recording operation of the recording / reproducing apparatus 1 in the first example.

  As shown in FIG. 4, the light beam B is condensed from the hologram laser 11 to the first recording layer L0 or the second recording layer L1 of the optical disc 100, thereby recording data (step S101). Specifically, if the light beam B is condensed on the first recording layer L0, data is recorded on the first recording layer L0, and if the light beam B is condensed on the second recording layer L1, the second is recorded. Data is recorded in the recording layer L1. In particular, since the optical disc 100 is an opposite track path system, data is first recorded from the inner circumference side to the outer circumference side of the first recording layer L0, and then, from the outer circumference side to the inner circumference side of the second recording layer L1. Data is recorded toward.

  On the other hand, in parallel with the data recording, the operation of the three-beam tracking servo circuit 41 is performed based on the light reception signal S31 generated by receiving the reflected light of the light beam B at the light receiving element of the hologram laser 11. A tracking servo control signal S41 is generated (step S111). Thereafter, tracking processing is performed based on the generated tracking servo control signal S41 (step S112).

  Thereafter, it is determined whether or not to end the recording operation under the control of the control unit 60 (step S121). As a result of this determination, when it is determined that the recording operation is to be ended (step S121: Yes), the recording operation is ended as it is, and the optical disc 100 is appropriately finalized, or the optical disc 100 is ejected from the recording / reproducing apparatus 1. Also good. On the other hand, if it is determined not to end the recording operation (step S121: No), the operations from step S101 or step S111 to step S112 are repeated again.

  Next, the manner in which the main beam and the two sub beams are condensed will be described with reference to FIGS. FIG. 5 is a plan view conceptually showing a manner of condensing the light beam B on the first recording layer L0, and FIG. 6 is a diagram showing condensing the light beam B on the second recording layer L1. FIG. 7 is a plan view conceptually showing an aspect, and FIG. 7 shows a light beam on the first recording layer L0 in the recording / reproducing apparatus according to the comparative example (recording / reproducing apparatus in which the position where the sub beam is condensed is not adjusted). FIG. 8 is a plan view conceptually showing a manner of condensing B, and FIG. 8 is a plan view conceptually showing a manner of condensing the light beam B on the second recording layer L1 in the recording / reproducing apparatus according to the comparative example. FIG. 5 to 8 illustrate spots formed on the recording layer by the light beam B (that is, the main beam and the two sub beams), the spot diameters and the like in FIGS. 5 to 8 are merely examples. It does not faithfully indicate the actual spot size.

  As shown in FIG. 5, when the light beam B is focused on the first recording layer L0 (that is, when data is recorded on the first recording layer L0), the main beam records the current data. A spot is formed on the groove track GT. Particularly in the first embodiment, the two sub beams are shifted from the spot formed by the main beam by a distance of 1.5 times the track pitch Tp (specifically, with respect to the groove track GT on which data is being recorded). Spots are formed on two land tracks LT with one groove track GT between them. Since data is recorded from the inner circumference side to the outer circumference side of the first recording layer L0, here, a sub beam forming a spot is formed on the upper right side of the spot formed by the main beam in FIG. 5 (that is, on the outer circumference side). A sub beam that forms a spot in the lower left (that is, on the inner peripheral side) of the spot formed by the main beam in FIG. 5 is referred to as a subsequent beam. Further, in FIG. 5, a recording portion where data has already been recorded is indicated by a shaded pattern. That is, no data is recorded on the groove track GT located at both ends of the spot formed by the preceding beam. On the other hand, data is recorded on the groove track GT located at both ends of the spot formed by the trailing beam.

  At this time, when the center of the spot formed by the main beam is not deviated from the approximate center of the groove track GT (that is, when no tracking shift occurs as shown by the solid line spot in FIG. 5), the preceding beam The center of the spot formed by each of the subsequent beams is formed at the approximate center of the land track LT. Therefore, the amount of reflected light of the preceding beam received by each of the two divided light receiving portions D1 and D2 is substantially the same, and the subsequent light received by each of the two divided light receiving portions D1 and D2. The amount of reflected light of the beam is substantially the same. That is, the amount of reflected light in the right and left portions of the spot formed by the preceding beam is the same, and the amount of reflected light in the right and left portions of the spot formed by the subsequent beam is the same. .

  On the other hand, when the center of the spot formed by the main beam deviates from the approximate center of the groove track GT, for example, to the right side (that is, when a tracking shift occurs as shown by the chain line spot in FIG. 5), the leading is preceded. The center of the spot formed by each of the beam and the trailing beam is formed at a position shifted to the right from the approximate center of the land track. Therefore, the amount of reflected light of the preceding beam received by each of the two divided light receiving portions D1 and D2 is different, and the subsequent beam received by each of the two divided light receiving portions D1 and D2 is different. The amount of reflected light is different. That is, the amount of reflected light in the right and left portions of the spot formed by the preceding beam is different, and the amount of reflected light in the right and left portions of the spot formed by the subsequent beam is different. . Based on the tracking servo control signal S41 that is generated by reflecting the difference in the amount of light, etc., tracking processing is performed so that they are equal.

  On the other hand, as shown in FIG. 6, when the light beam B is focused on the second recording layer L1 (that is, when data is recorded on the second recording layer L1), the main beam and the sub beam are similarly generated. Each of them forms a spot. Since the data is recorded from the outer peripheral side to the inner peripheral side of the second recording layer L1, here, the sub-beam that forms a spot in the lower left (that is, on the inner peripheral side) of the spot formed by the main beam in FIG. Is referred to as a preceding beam, and a sub beam that forms a spot on the upper right (ie, on the outer peripheral side) of the spot formed by the main beam in FIG. At this time, also in the second recording layer L1, as in the first recording layer L0, no data is recorded on the groove track GT located at both ends of the spot formed by the preceding beam. On the other hand, data is recorded on the groove track GT located at both ends of the spot formed by the trailing beam. For this reason, as in the case of the first recording layer L0, a suitable tracking process is also performed in the second recording layer L1.

  Here, a recording / reproducing apparatus according to a comparative example will be described. Unlike the recording / reproducing apparatus 1 according to the first embodiment, the recording / reproducing apparatus according to the comparative example is located at a position shifted by a distance 0.5 times the track pitch Tp from the spot formed by the main beam (specifically, , Two sub-beams forming a spot (on the two land tracks LT adjacent to the groove track GT on which data is being recorded) are generated. The recording / reproducing apparatus currently on the market employs a three-beam tracking system in the form shown in FIGS.

  When the recording / reproducing apparatus according to the comparative example records data on the first recording layer L0, the positions of the spots formed by the preceding beam and the succeeding beam are shown in FIG. Specifically, no data is recorded in the groove tracks GT positioned at both ends of the spot formed by the preceding beam, and data is stored in the groove tracks GT positioned at both ends of the spot formed by the subsequent beam. It is recorded. Accordingly, the tracking process is suitably performed as in the recording / reproducing apparatus 1 according to the first embodiment.

  On the other hand, when the recording / reproducing apparatus according to the comparative example records data on the second recording layer L1, the positions of spots formed by the preceding beam and the succeeding beam are shown in FIG. Specifically, data is recorded on the groove track GT located in the right part of the spot formed by the preceding beam, and no data is recorded in the groove track GT located in the left part of the spot of the preceding beam. . Data is recorded on the groove track GT located in the right part of the spot formed by the trailing beam, and data is recorded in the groove track GT located in the left part of the spot formed by the trailing beam. Absent.

  For this reason, even when the center of the spot formed by the main beam is not deviated from the approximate center of the groove track GT (that is, when there is no tracking shift as shown by the solid spot in FIG. 8), The amount of reflected light in the right and left portions of the spot formed by the preceding beam is different, and the amount of reflected light in the right and left portions of the spot formed by the subsequent beam is different. This is because the reflectance of the light beam B is different between the groove track GT (or land track LT) in which no data is recorded and the groove track GT (or land track LT) in which the data is recorded. Yes. For this reason, in the recording / reproducing apparatus according to the comparative example, even when the tracking deviation does not occur, it can be recognized as if the tracking deviation has occurred. As a result, there arises a disadvantage that an incorrect tracking process based on an incorrect tracking servo control signal can be performed.

  However, in the recording / reproducing apparatus 1 according to the first embodiment, in order to prevent such an erroneous tracking process from being performed, each of the two sub-beams has a gap between the groove track GT which is recording data. Spots are formed on two land tracks LT on which two groove tracks GT are arranged. In other words, the sub-beam that forms a spot that satisfies such a positional relationship is generated by the grating element 12. Accordingly, even when data is recorded on the second recording layer L1 in which the data recording direction is different from that of the first recording layer L0, it is possible to perform a suitable tracking process.

  As described above, according to the recording / reproducing apparatus 1 in the first embodiment, the tracking process using the three-beam tracking method for the multilayer optical disk having a plurality of recording layers having different data recording directions. Can be performed appropriately.

  In the recording / reproducing apparatus 1 according to the first embodiment, if the inclination of the grating element 12 is changed or the interval or arrangement of the slits is adjusted as appropriate, a sub beam for forming a spot in the above-described manner is generated. can do. In other words, the recording / reproducing apparatus 1 according to the first embodiment can be realized relatively easily, and the effect obtained by this implementation is remarkably superior to the recording / reproducing apparatus according to the comparative example. is there.

(Second embodiment of recording / reproducing apparatus)
Next, a recording / reproducing apparatus 2 as a second embodiment of the recording apparatus of the present invention will be described with reference to FIGS. In addition, about the structure and operation | movement similar to the recording / reproducing apparatus 1 based on 1st Example, the same referential mark and step number are attached | subjected and the detailed description is abbreviate | omitted.

(1) Basic Configuration The recording / reproducing apparatus 2 according to the second embodiment has substantially the same configuration as the recording / reproducing apparatus 1 according to the first embodiment described with reference to FIG. The recording / reproducing apparatus 2 according to the second embodiment is different from the recording / reproducing apparatus 1 according to the first embodiment in the interval and arrangement of the slits of the grating element 12. The grating element 12 included in the recording / reproducing apparatus 2 according to the second embodiment can generate one main beam and four sub beams by diffracting the light beam B emitted from the hologram laser 11. It is configured. In particular, four sub-beams that form spots on the recording surfaces of the first recording layer L0 and the second recording layer L1 are formed in a pattern that will be described in detail later.

(2) Operation Principle Next, with reference to FIG. 9, the operation principle (particularly the recording operation) of the recording / reproducing apparatus 2 in the second embodiment will be described. FIG. 9 is a flowchart conceptually showing a flow of the recording operation of the recording / reproducing apparatus 2 in the second example.

  As shown in FIG. 9, data is recorded by converging the light beam B from the hologram laser 11 onto the first recording layer L0 or the second recording layer L1 of the optical disc 100 (step S101).

  On the other hand, in parallel with the data recording, the actual tracking of the four sub-beams generated in the grating element 12 under the control of the control unit 60 that constitutes a specific example of the “selecting means” of the present invention. Two sub-beams used for processing are selected (step S131). Here, for example, among the plurality of sub-beams, a sub-beam in which no data is recorded on the groove track GT positioned at both ends of the spot to be formed is selected. Alternatively, among the plurality of sub beams, a sub beam in which data is recorded on the groove track GT located at both ends of the spot to be formed is selected. In other words, sub-beams having the same recording state on the groove track GT located at both end portions of the spot to be formed are selected, and sub-beams having different recording states on the groove track GT located at both end portions of the spot to be formed are not selected.

  Thereafter, the signal component resulting from the reflected light of the main beam and the two sub-beams selected in step S131 out of the received light signal S31 generated when the reflected light of the light beam B is received by the light receiving element of the hologram laser 11. Based on the above, a tracking servo control signal S41 is generated by the operation of the three-beam tracking servo circuit 41 (step S111). Thereafter, tracking processing is performed based on the generated tracking servo control signal S41 (step S112).

  In the second embodiment, the tracking process using the three-beam tracking method is performed as in the first embodiment. That is, the “3-beam tracking method” in the second embodiment is a tracking processing method using the reflected light of one main beam and two sub beams, and how many sub beams are generated in the grating element 12. Is not a problem.

  Next, a mode in which the main beam and the four sub beams are condensed will be described with reference to FIGS. 10 to 13. In the second embodiment, by adjusting the interval and arrangement of the slits of the grating element 12, for example, two kinds of condensing modes described below are given as specific modes. FIG. 10 is a plan view conceptually showing one specific mode of condensing the light beam B on the first recording layer L0, and FIG. 11 is a light beam B on the second recording layer L1. FIG. 12 is a plan view conceptually showing one specific mode of condensing the light beam, and FIG. 12 is a plan view conceptually showing another specific mode of condensing the light beam B on the first recording layer L0. FIG. 13 is a plan view conceptually showing another specific aspect of condensing the light beam B on the second recording layer L1. 10 to 13, as in FIGS. 5 to 8, the spot diameter and the like are merely examples, and do not faithfully indicate the actual spot size.

  As shown in FIG. 10, in one specific aspect, when the light beam B is focused on the first recording layer L0, the two sub beams are divided into a spot formed by the main beam and a track pitch Tp of 0.5. Spots 202 and 203 are formed at positions shifted by a double distance. Further, the other two sub beams form spots 201 and 204 at positions shifted from the spot of the main beam by a distance 1.5 times the track pitch Tp. In this case, two sub-beams that form the spots 202 and 203 at positions shifted by a distance 0.5 times the track pitch Tp from the spot formed by the main beam are selected as the sub-beams used in the actual tracking process. No data is recorded in the groove track GT positioned at both ends of the spot 203 formed by the selected preceding beam, and the groove track GT positioned at both ends of the spot 202 formed by the selected subsequent beam. The data is recorded in. By selecting such a sub-beam, a suitable tracking process as described above can be performed. However, the two sub beams forming the spots 201 and 204 at positions shifted by a distance 1.5 times the track pitch Tp from the spot formed by the main beam may be selected as the sub beams used for the tracking process. Needless to say.

  On the other hand, as shown in FIG. 11, when the light beam B is condensed on the second recording layer L1, the four sub beams form spots 211 to 214 as well. In this case, two sub-beams that form the spots 211 and 214 are selected as sub-beams used in the actual tracking process at positions shifted by a distance 1.5 times the track pitch Tp from the spot formed by the main beam. No data is recorded in the groove track GT positioned at both ends of the spot 211 formed by the selected preceding beam, and the groove track GT positioned at both ends of the spot 214 formed by the selected subsequent beam. The data is recorded in. By selecting such a sub-beam, a suitable tracking process as described above can be performed. At this time, the two sub beams forming the spots 212 and 213 are not selected as the sub beams used in the actual tracking process. This is because data is recorded on the groove track GT located on the right side of the spot 212 (or 213), and data is recorded on the groove track GT located on the left side of the spot 212 (or 213). Because it is not done. That is, the recording mode or state of data differs between the right side portion and the left side portion of each of the spots 212 and 213.

  As shown in FIG. 12, in another specific embodiment, when the light beam B is condensed on the first recording layer L0, the four sub beams are formed by a spot formed by the main beam and a track pitch Tp of 0.5. Spots 201 to 204 are formed at positions shifted by a double distance. In particular, the spots 201 and 203 are formed on the traveling direction side of the main beam with reference to the spot formed by the main beam. The spots 202 and 204 are formed on the side opposite to the traveling direction of the main beam with reference to the spot formed by the main beam. That is, the four sub-beams form spots 201 to 204 that draw X around the spot formed by the main beam. In this case, two sub beams forming the spots 202 and 203 are selected as the sub beams used in the actual tracking process. No data is recorded in the groove track GT positioned at both ends of the spot 203 formed by the selected preceding beam, and the groove track GT positioned at both ends of the spot 202 formed by the selected subsequent beam. The data is recorded in. By selecting such a sub-beam, a suitable tracking process as described above can be performed. At this time, the two sub beams forming the spots 201 and 204 are not selected as the sub beams used in the actual tracking process. This is because the mode or state of data recording differs between the right side portion and the left side portion of each spot 201 and 204.

  On the other hand, as shown in FIG. 13, when the light beam B is condensed on the second recording layer L1, the four sub beams form spots 211 to 214 as well. In this case, two sub beams forming the spots 211 and 214 are selected as the sub beams used in the actual tracking process. No data is recorded in the groove track GT positioned at both ends of the spot 211 formed by the selected preceding beam, and the groove track GT positioned at both ends of the spot 214 formed by the selected subsequent beam. The data is recorded in. By selecting such a sub-beam, a suitable tracking process as described above can be performed. At this time, the two sub beams forming the spots 212 and 213 are not selected as the sub beams used in the actual tracking process. This is because the mode or state of data recording differs between the right side portion and the left side portion of each spot 212 and 213.

  As described above, according to the recording / reproducing apparatus 2 in the second embodiment, similarly to the recording / reproducing apparatus 1 in the first embodiment, the multi-layer disc having a plurality of recording layers having different data recording directions is used. On the other hand, it is possible to appropriately perform tracking processing using the three-beam tracking method.

  Further, according to the recording / reproducing apparatus 2 in the second embodiment, as shown in FIG. 10, depending on the case, a plurality of sets of sub-beams (specifically, a set of sub-beams and spots forming the spots 202 and 203). Tracking processing can be performed using a set of sub-beams forming 201 and 204. For this reason, even when the groove track GT or the land track LT is scratched or the like and a suitable tracking process cannot be performed using the sub beam related to one set, the sub beam related to the other set is used. A suitable tracking process can be performed. This is an extremely excellent advantage from the viewpoint of realizing a suitable recording operation.

  In addition, you may comprise so that the verification process of the recorded data may be performed using the sub beam which is not used for a tracking process among several sub beams. As a result, the verify process can be performed efficiently without affecting the normal recording operation or the tracking process.

  Note that the manner of generating the plurality of sub-beams (that is, the interval and arrangement of the slits of the grating element 12) is not limited to the above-described one, and can take any manner. In short, if a sub beam having substantially the same data recording mode or state can be selected in the right side portion and the left side portion of the spot formed by each of the plurality of sub beams, the tracking process is preferably performed as described above. Can be performed.

  In the above-described embodiment, all four sub beams are irradiated onto the optical disc 100. However, the sub beam used for tracking processing may be selectively irradiated. That is, for example, in the case of FIGS. 10 and 11, when data is recorded on the first recording layer L0, the sub-beams forming the spots 202 and 203 are selectively irradiated, and the data is recorded on the second recording layer L1. In the case of recording, it is sufficient to selectively irradiate the sub beams forming the spots 211 and 214. Of course, the same applies to the cases of FIGS.

  As described above, in order to selectively irradiate the sub beam used for the tracking process, as shown in FIG. 14, a grating element 12 including a liquid crystal element (hereinafter, appropriately referred to as “liquid crystal grating element 12a”) is used. 14 may be configured to electrically change the angle of the slit (or the arrangement of the slits, etc.) Fig. 14 is a plan view conceptually showing the configuration of the grating element including the liquid crystal element. .

  As shown in FIG. 14A, a liquid crystal grating element 12a including a plurality of first electrodes 121 and a plurality of second electrodes 122 formed along a direction different from the first electrodes 121 may be used. Good. When data is recorded on the first recording layer L0, a slit is formed in accordance with the pattern of the first electrode 121 by applying a voltage to the liquid crystal element using the first electrode 121. As a result, for example, the sub-beams forming the spots 202 and 203 in FIG. 12 and the like are irradiated to the optical disc 100, while the sub-beams forming the spots 201 and 204 are not irradiated to the optical disc 100. When data is recorded on the second recording layer L 1, a slit is formed according to the pattern of the second electrode 122 by applying a voltage to the liquid crystal element using the second electrode 122. As a result, for example, the sub-beams that form the spots 211 and 214 in FIG. 13 are irradiated onto the optical disc 100, and the sub-beams that form the spots 212 and 213 are not irradiated onto the optical disc 100.

  As described above, if the electrode used when applying a voltage to the liquid crystal element is changed (that is, if the electrode for supplying the current for driving the liquid crystal element is changed), the slit interval or the liquid crystal grating element 12a is relatively easily changed. Arrangement etc. can be changed. As a result, a plurality of sub beams can be generated, but the optical disc 100 can be selectively irradiated with the sub beams used for tracking processing.

  In such a liquid crystal grating element 12a, as shown in FIG. 14B, the first electrode 121, the insulating layer 123, the second electrode 122, the liquid crystal element 124, and the other end electrode 125 are laminated in this order. Is done. Each of the first electrode 121 and the second electrode 122 is patterned as shown in FIG. 14A, and an insulating layer 123 is formed between the first electrode 121 and the second electrode 122. Therefore, the first electrode 121 and the second electrode 122 do not interfere with each other. Therefore, the liquid crystal grating element 12a used in the recording / reproducing apparatus 2 according to the second embodiment can be realized relatively easily. Alternatively, a liquid crystal grating element in which two liquid crystal grating elements are stacked may be used as the liquid crystal grating element 12a used in the recording / reproducing apparatus 2 according to the second embodiment.

  Next, a modified operation example of the recording / reproducing apparatus 2 according to the second embodiment will be described with reference to FIG. FIG. 15 is a flowchart conceptually showing a flow of the modified operation example of the recording / reproducing apparatus 2 in the second example. In addition, about the structure or operation | movement common to description in the Example mentioned above, the same referential mark or step number is attached | subjected also in FIG. 15, and the detailed description is abbreviate | omitted.

  As shown in FIG. 15, in the modified operation example, before data is recorded, it is preferable depending on whether the recording layer that is the target of the recording operation is the first recording layer or the second recording layer in advance. A sub-beam is selected (step S131).

  After that, a tracking servo control signal is generated based on the sub beam selected before recording data (step S111), tracking processing is executed (step S112), and data is recorded (step S101). Even if the sub-beam is selected before data is recorded in this way, the above-described various benefits can be suitably enjoyed.

  The present invention is not limited to application to the two-layer type optical disc 100, and can also be applied to a multilayer type optical disc having three or more layers. That is, for a multi-layer type optical disc having a plurality of recording layers in which data is recorded from the inner peripheral side toward the outer peripheral side and a plurality of recording layers in which data is recorded from the outer peripheral side toward the inner peripheral side. Can also be applied.

  Furthermore, for single-layer optical discs, based on whether data is recorded from the inner circumference side to the outer circumference side or from the outer circumference side to the inner circumference side in each optical disc, etc. The above-described operation can be performed. As a result, it becomes possible to appropriately perform tracking processing using, for example, a three-beam tracking method on optical disks having different data recording directions (or data recording modes).

  Further, in the above-described embodiment, an optical pickup is configured using a hologram laser having a function as a light source and a light receiving unit (detector). However, the application of the present invention is not limited to this. That is, an optical pickup in which a light source and a light receiving unit are separately provided may be used.

  The application of the present invention is not limited to an optical disc recording / reproducing apparatus having a structure in which a groove track and a land track are provided in both the first recording layer L0 and the second recording layer L1. That is, the present invention can be applied to an optical disc recording / reproducing apparatus in which a groove track and a land track are provided only in the first recording layer L0 and no groove track and a land track are provided in the second recording layer L1. In this case, for example, recording of information on the second recording layer L1 and reproduction of information recorded on the second recording layer L1 are executed using a groove track and a land track provided in the first recording layer L0. .

  In the above-described embodiments, the optical disc 100 as an example of the recording medium and the recorder or player related to the optical disc 100 as an example of the recording / reproducing apparatus have been described. However, the present invention is not limited to the optical disc and the recorder. The present invention can also be applied to various recording media compatible with high-density recording or high transfer rate, as well as its recorder or player.

  The present invention is not limited to the above-described embodiments, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and a recording apparatus accompanied with such changes Also, a computer program for recording control and a recording control is also included in the technical scope of the present invention.

It is the top view and sectional view which show schematic structure of the optical disk used in a present Example. It is a partial expansion perspective view in the recording surface of the optical disk used in a present Example. 1 is a block diagram conceptually showing the basic structure of a recording / reproducing apparatus in a first example. 3 is a flowchart conceptually showing a flow of a recording operation of the recording / reproducing apparatus in the first example. It is a top view which shows notionally the aspect of condensing of the light beam on the 1st recording layer. It is a top view which shows notionally the aspect of condensing of the light beam on the 2nd recording layer. In the recording / reproducing apparatus which concerns on a comparative example, it is a top view which shows notionally the aspect of condensing of the light beam B on the 1st recording layer. In the recording / reproducing apparatus which concerns on a comparative example, it is a top view which shows notionally the aspect of condensing of the light beam B on the 2nd recording layer. It is a flowchart which shows notionally the flow of the recording operation | movement of the recording / reproducing apparatus based on 2nd Example. FIG. 6 is a plan view conceptually showing one specific aspect of condensing a light beam B on the first recording layer L0. It is a top view which shows notionally one specific aspect of condensing of the light beam B on the 2nd recording layer L1. It is a top view which shows notionally other specific aspects of condensing of the light beam B on the 1st recording layer L0. It is a top view which shows notionally other specific aspects of condensing of the light beam B on the 2nd recording layer L1. It is a top view which shows notionally the structure of the grating element containing a liquid crystal element. It is a flowchart which shows notionally the flow of the deformation | transformation operation | movement of the recording / reproducing apparatus based on 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording / reproducing apparatus 11 Hologram laser 12 Grating element 14 Objective lens 15 Actuator part 41 3 beam tracking servo circuit 44 Tracking drive circuit 60 Control part 100 Optical disk L0 1st recording layer L1 2nd recording layer

Claims (15)

A recording means for recording data by irradiating a recording medium with a light beam;
A main beam disposed between the recording means and the recording medium and used for recording the data by diffracting the light beam and for performing tracking processing, and for performing the tracking processing. Diffractive means for generating a plurality of sub-beams,
Selecting means for selecting at least two of the plurality of sub-beams;
A recording apparatus comprising: a tracking unit that performs the tracking process using a tracking signal generated from the main beam and the selected at least two sub-beams.   The recording apparatus according to claim 1, wherein the selection unit selects the at least two sub-beams according to a recording direction of the data on the recording medium. The recording medium includes a first recording layer for recording data in one direction and a second recording layer for recording the data in another direction different from the one direction,
3. The recording unit according to claim 1, wherein the recording unit records the data on the recording medium by irradiating a light beam so as to be focused on the first recording layer or the second recording layer. The recording device described.   The selection unit selects the at least two sub-beams among the plurality of sub-beams according to which of the first recording layer and the second recording layer the light beam is focused on. The recording apparatus according to claim 3. The recording medium is formed with concentric or spiral recording tracks for recording the data,
The selection means includes, as the at least two sub-beams, one sub-beam in which the recording track on which the data has been recorded is arranged at both ends of the focused spot and the data at both ends of the focused spot. 5. The recording apparatus according to claim 1, wherein the recording apparatus selects another sub-beam in which an unrecorded recording track is arranged. The recording medium is formed with concentric or spiral recording tracks for recording the data,
The diffraction means includes (i) a main track that is the recording track on which the main beam is condensed and a first adjacent track that is the recording track adjacent to the main track; and (ii) the first track. 6. The plurality of sub-beams that are condensed at substantially the center between each adjacent track and a second adjacent track that is the recording track adjacent to the first adjacent track. The recording device according to any one of the above. The recording medium is formed with concentric or spiral recording tracks for recording the data,
The diffractive means is substantially the center between a main track that is the recording track on which the main beam is condensed and two adjacent tracks that are the recording tracks adjacent to the main track, and the 6. The plurality of sub-beams that are focused in a traveling direction of the main beam and a direction opposite to the traveling direction with a position where the main beam is focused as a central point are generated. The recording device according to any one of the above.   8. The control device according to claim 1, further comprising control means for controlling the diffraction means so that the recording medium is selectively irradiated with the selected at least two sub-beams among the plurality of sub-beams. The recording device according to any one of the above. Recording means for recording the data by irradiating a light beam onto a recording medium on which concentric or spiral recording tracks for recording data are formed;
A main beam disposed between the recording means and the recording medium and used for recording the data by diffracting the light beam and for performing tracking processing, and for performing the tracking processing. And diffractive means for generating at least two sub-beams, wherein at least one recording track is located between the main beam and the main beam;
A recording apparatus comprising: tracking means for executing the tracking process by a tracking signal generated from reflected light of the main beam and the at least two sub beams. The recording medium includes a first recording layer for recording data in one direction and a second recording layer for recording the data in another direction different from the one direction,
The said recording means records the said data on the said recording medium by irradiating a light beam so that it may concentrate on the said 1st recording layer or the said 2nd recording layer, The said recording medium is characterized by the above-mentioned. Recording device.   The diffracting means includes, as the at least two sub-beams, one sub-beam in which the recording track on which the data has been recorded is arranged at both ends of the focused spot and the data at both ends of the focused spot. The recording apparatus according to claim 9, wherein the recording apparatus generates another sub beam in which an unrecorded recording track is arranged. Recording means for recording data by irradiating a recording medium with a light beam; and recording means for recording the data by diffracting the light beam and being disposed between the recording means and the recording medium A recording method in a recording apparatus comprising a main beam used for processing and a diffractive means for generating a plurality of sub beams used for performing the tracking processing,
A selection step of selecting at least two sub-beams among the plurality of sub-beams;
And a tracking step of executing the tracking process by a tracking signal generated from the main beam and the selected at least two sub-beams. A recording means for recording the data by irradiating a light beam onto a recording medium on which concentric or spiral recording tracks for recording data are formed, and between the recording means and the recording medium And a main beam used to record the data by diffracting the light beam and to perform a tracking process, and to be used to perform the tracking process and at least between the main beam A recording method comprising: a diffractive means for generating at least two sub-beams in which one recording track is located;
A control step of controlling the recording means to irradiate the light beam;
And a tracking step of executing the tracking process by a tracking signal generated from reflected light of the main beam and the at least two sub beams.   A computer program for recording control for controlling a computer provided in the recording apparatus according to claim 1, wherein the computer is at least a part of the selection unit and the tracking unit. A computer program that functions as a computer program. A computer program for recording control for controlling a computer provided in the recording apparatus according to any one of claims 9 to 11, wherein the computer program functions as the tracking means. .

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