WO2014045389A1

WO2014045389A1 - Optical recording/reproduction device and method

Info

Publication number: WO2014045389A1
Application number: PCT/JP2012/074185
Authority: WO
Inventors: 隆碓井; 小川　昭人; 渡部　一雄; 岡野　英明; 真拡齊藤
Original assignee: 株式会社東芝
Priority date: 2012-09-21
Filing date: 2012-09-21
Publication date: 2014-03-27
Also published as: WO2014046066A1

Abstract

An optical recording/reproduction device according to an embodiment of the present invention records data on a recording medium in which one or more recording layers on which data is recorded and a guide layer used for positioning are layered so as to be separated from one another, and comprises an end position detection unit and a postscript start position setting unit. The end position detection unit detects the end position of first data when a recorded region relating to said first data exists in a first recording layer of the recording medium and second data is to be newly recorded on the first recording layer. The postscript start position setting unit sets the recording start position of the second data to a position that overlaps more with the recorded region than the end position.

Description

Optical recording / reproducing apparatus and method

Embodiments described herein relate generally to an optical recording / reproducing apparatus and method for recording / reproducing information on / from an optical recording medium.

Optical information recording media represented by CDs (Compact Discs), DVDs (Digital Versatile Discs), BDs (Blu-ray (registered trademark) Discs) and the like have been used to shorten the wavelength of laser light and the numerical aperture of objective lenses ( The recording density is increased by increasing NA). However, all of these are said to be approaching the limits due to technical reasons and the like, and an increase in recording density by other means and methods is desired. Among various proposals, in recent years, a guide layer method in which a guide layer having tracking servo information (groove) is provided separately from a recording layer in an optical information recording medium (multilayer optical disc) having a multi-layered recording layer. Multi-layer optical discs have been proposed. Thereby, the structure of the recording layer to be laminated becomes simple, and the disc manufacturing cost can be suppressed.
However, depending on the state of tilt of the disc, there is a possibility that data may be overwritten on a track on which data has been previously recorded. In the worst case, data may be destroyed. Therefore, there is a technique for preventing overwriting by providing a certain unrecorded area from the final position of the recorded data and starting recording of data to be additionally recorded thereafter.

US Pat. No. 7,948,853 JP 2010-40093 A

However, in the above-described method, there is a blank area where data is not written at the data boundary before and after the additional recording, and it is not possible to continuously obtain a tracking error signal (DPD signal) for following the pit string during reproduction. For this reason, for example, when the head of data after appending is played back, it cannot be played back continuously from the inner circumference, and once accessed using a coarse actuator far from the data start position after appending. In addition, it is necessary to perform a track jump and move to the top position. In addition, when the additional data amount is short, it is difficult to access the additional data range in the first place. In such a case, the data access speed at the time of reproduction is remarkably impaired, resulting in a disadvantage to the user.

The present disclosure has been made in order to solve the above-described problems, and an object thereof is to provide an optical recording / reproducing apparatus and method that allow easy data access.

The optical recording / reproducing apparatus according to the present embodiment records data on a recording medium in which one or more recording layers on which data is recorded and a guide layer used for positioning are stacked apart from each other. In addition, the terminal position detection unit and the additional write start position setting unit are included. The end position detection unit, when there is a recorded area related to the first data in the first recording layer of the recording medium, and when the second data is newly recorded on the first recording layer, Detect the end position. The additional recording start position setting unit sets the recording start position of the second data to a position that overlaps the recorded area rather than the end position.

The figure which shows the layer structure of the optical recording medium used by this embodiment. The figure explaining the spot shift | offset | difference in case a tilt generate | occur | produces in an optical recording medium. 1 is a block diagram showing an optical recording / reproducing apparatus according to an embodiment. 1 is a diagram showing an optical pickup head according to the present embodiment. The block diagram which shows the detail of a postscript control part. The figure explaining the recording method of the optical recording / reproducing apparatus in this embodiment. The figure explaining the relationship of the overlap of the radial direction in a buffer area | region. The block diagram which shows the postscript control part which concerns on the modification of this embodiment. The figure explaining the angle area | region which divided | segmented the optical recording medium in the circumferential direction. The figure which shows an example of the data recording in the buffer area | region divided | segmented into the circumferential direction. FIG. 3 is a schematic diagram of data in a buffer area of the entire optical recording medium divided in the circumferential direction. The block diagram which shows the reproduction | regeneration control part of the optical recording / reproducing apparatus in this embodiment. The figure which shows the reproducing | regenerating method of the optical recording / reproducing apparatus in this embodiment.

Hereinafter, an optical recording / reproducing apparatus and method according to the present embodiment will be described in detail with reference to the drawings. Note that, in the following embodiments, the same reference numerals are assigned to the same operations, and duplicate descriptions are omitted as appropriate.
The layer structure of the optical recording medium used in the optical recording / reproducing apparatus according to the present embodiment will be described with reference to FIG.
An optical recording medium 100 used in the optical recording / reproducing apparatus according to the present embodiment is a guide layer type multilayer medium, and a guide layer 101 having a groove and applying tracking servo and a recording layer 102 for recording data are provided separately. It is done. Thereby, the structure of the recording layer itself to be laminated can be simplified, and the manufacturing cost of the optical recording medium can be suppressed. In the example shown in FIG. 1, one guide layer 101 and a recording layer 102 in which 10 layers from L0 to L9 are stacked are formed in an optical recording medium. Guide light 103 is focused on the guide layer 101, and recording light 104 is focused on the recording layer 102. Data recording and data reproduction are performed by focusing the recording light 104 along the position of the guide light 103.

Next, spot deviation when tilt occurs in the optical recording medium will be described with reference to FIG.
FIG. 2 is a schematic diagram showing spot positions at the time of additional writing when the guide layer 101 and the recording layer 102 are separated. Here, the additional recording means that the first data is first recorded, the optical recording medium is removed from the optical recording / reproducing apparatus, and then the optical recording medium is inserted into the optical recording / reproducing apparatus again. The second data is recorded.

FIG. 2A shows a case where no tilt occurs in the optical recording medium, and the track position 201 on the guide layer 101 indicates the track position 202 of the recording layer 102 located vertically below. In this state, data is recorded on the recording layer from the track on the left side of the guide layer to the Nth track, and a data string is formed on the recording layer as shown in FIG.

Fig. 2 (b) shows a case where data is added after Fig. 2 (a). When data is added, it is completely unknown how the optical recording medium is tilted, and it is natural to think that a tilt state different from the previous recording occurs. In the example of FIG. 2B, it is a state when the tilt θ occurs. Since it can be extracted from the management information that the previously recorded data has been recorded up to the Nth track, additional recording is started from the N + 1th track in the case of a normal optical recording medium. However, when the guide layer 101 and the recording layer 102 are separated (distance d), the beam spot of the recording layer 102 is a track position 202 shifted by d × tan θ in terms of the optical recording medium coordinates. As a result, it may interfere with the previously recorded track, and in the worst case, the data may be destroyed.

Even in a so-called lens shift state in which the objective lens is slightly displaced in the radial direction of the optical recording medium, the spot position of the guide beam for reproducing the guide layer and the spot position of the recording / reproducing beam for performing recording / reproduction are relatively It is known to shift. This change in lens shift is also considered to cause the same problem as the tilt.

It should be noted that the intentional pause of recording due to, for example, buffer underrun or recording strategy / servo parameter adjustment, such as resuming recording immediately without re-inserting the optical recording medium, causes extreme tilt and lens shift conditions. It is assumed that there is no tilt, that is, a tilt that causes a problem does not occur.

Next, an optical recording / reproducing apparatus according to the present embodiment that solves the above-described problems will be described with reference to the block diagram of FIG.
The optical recording / reproducing apparatus 300 according to this embodiment includes a CPU 301, an interface unit 302, a RAM 303, an NV-RAM 304, a ROM 305, an error correction unit 306, an additional write control unit 307, a spindle motor control unit 308, a spindle motor 309, a rotary encoder 310, Optical pickup head 311, feed motor controller 312, feed motor 313, screw shaft 314, PLL controller 315, laser modulation controller 316, RF amplifier (also referred to as error signal generator) 317, collimator lens actuator controller 318, focus A control unit 319, a track control unit 320, a data reproduction unit 321, an address reproduction unit 322, and a reproduction control unit 1200 are included.

The CPU 301 receives an operation command from the host device 350 via the interface unit 302. The CPU 301 generates a control signal in accordance with the operation command, and an error correction unit 306, a spindle motor control unit 308, a feed motor control unit 312, a PLL control unit 315, a laser modulation control unit 316, a collimator lens actuator control unit 318, a focus described later The entire optical recording / reproducing apparatus 300 such as the control unit 319, the track control unit 320, and the data reproducing unit 321 is comprehensively controlled. Further, the CPU 301 uses the RAM 303 as a work area, appropriately refers to the parameters of each device recorded in the nonvolatile memory NV-RAM 304, and performs a predetermined operation according to the control program recorded in the ROM 305.

The error correction unit 306 corrects the reproduction data with errors.

The additional write control unit 307 receives data from a data reproduction unit 321 (to be described later) and address information from the address reproduction unit 322, and refers to the data and the address information as appropriate to perform additional data processing. Details of the write-once control unit 307 will be described later with reference to FIG.

The reproduction control unit 1200 receives a tracking error signal output from an RF amplifier 317, which will be described later, and address information from the address generation unit 322, and controls the track control unit 320 based on a command from the CPU 301. The operation of the reproduction control unit 1200 will be described later with reference to FIG.

The spindle motor control unit 308 receives a control signal from the CPU 301 via the signal bus 351 and generates a spindle motor drive signal.

The spindle motor 309 receives a spindle motor drive signal from the spindle motor control unit 308, and rotationally drives the optical recording medium 100 installed according to the spindle motor drive signal. At this time, a rotation angle signal is provided from a rotary encoder 310 provided in the spindle motor 309. As the rotation angle signal, for example, five pulses are generated when the spindle motor makes one rotation. From this rotation angle signal, the rotation angle and the number of rotations of the spindle motor can be determined.

The optical pickup head 311 generates a light reception signal by irradiating the optical recording medium 100 with a laser and receiving reflected light from the optical recording medium 100. The optical pickup head is connected via a feed motor 313, a gear, and a screw shaft 314. The detailed structure of the optical pickup head 311 will be described later with reference to FIG.

The feed motor control unit 312 receives the control signal and generates a feed motor drive signal.

The feed motor 313 receives the feed motor drive signal from the feed motor control unit 312 and rotates in accordance with the feed motor drive signal, thereby moving the optical pickup head in the radial direction of the optical recording medium 100.

The PLL control unit 315 receives a control signal from the CPU 301 and performs phase synchronization to generate a recording clock signal for recording and a reproduction clock signal for reproduction.

The laser modulation control unit 316 records data to be recorded from the host device 350 via the interface unit 302 when recording data (mark formation), a recording clock signal from the PLL control unit 315, and the CPU 301 and additional recording control. A control signal is received from the unit 307. The laser modulation control unit 316 generates a writing signal based on the recording data, the recording clock signal, and the control signal, and provides it to the optical pickup head 311. Further, the laser modulation control unit 316 provides a read signal smaller than the write signal to the optical pickup head 311 when reading data. Further, the laser modulation control unit 316 causes the optical pickup head 311 to emit light at the reproduction laser power, the recording laser power, and the erasing laser power set by the CPU 301 based on the light reception signal from the optical pickup head 311. Control the included laser diode.

The RF amplifier 317 receives a light reception signal from the optical pickup head 311. The RF amplifier 317 generates a first focus error signal, a second focus error signal, a first tracking error signal, a second tracking error signal, and a reproduction signal based on the received light signal. The first focus error signal is a signal indicating an error from the just focus of the guide layer. The second focus error signal is a signal indicating an error from the just focus of the recording layer. The first tracking error signal is a signal indicating an error between the center of the laser beam spot and the center of the guide track. The second tracking error signal is a signal indicating an error between the laser beam spot center and the recorded track center. The reproduction signal is a full addition signal of the received light signal.

The collimator lens actuator control unit 318 receives the first focus error signal from the RF amplifier 317 based on the command from the CPU 301, and generates a collimator lens focus drive signal according to the first focus error signal. The collimator lens focus drive signal is supplied to the drive coil in the focus direction of the collimator lens lens actuator. Thus, focus servo is performed in which the red laser light is always just focused on the guide layer of the optical recording medium 100.

The focus control unit 319 receives the second focus error signal from the RF amplifier 317 based on the command from the CPU 301, and generates a focus drive signal according to the second focus error signal. The focus drive signal is supplied to the drive coil in the focus direction of the objective lens actuator. As a result, focus servo is performed in which the blue laser light is always just focused on the recording layer of the optical recording medium 100.

The track control unit 320 receives the first tracking error signal and the second tracking error signal from the RF amplifier 317 based on a command from the CPU 301. The track controller 320 generates a track driving signal according to the first tracking error signal and the second tracking error signal. The track drive signal is supplied to a drive coil in the tracking direction of the objective lens actuator. As a result, tracking servo is performed in which the laser beam always traces the track formed on the optical recording medium 100.
When the objective lens included in the optical pickup head 311 is controlled by the track control unit 320, the feed motor control unit 312 controls the feed motor 313, that is, the optical pickup head 311 so that the objective lens is positioned near a predetermined position. The That is, tracking servo control is performed in a direction in which the amount of deviation of the optical recording medium 100 from the predetermined position of the objective lens in the radial direction (hereinafter referred to as lens shift amount) is reduced.

By performing the above-described focus servo and tracking servo, the optical recording medium 1 corresponds to the recording data in the full addition signal of the light reception signal from each photodetection cell of the photodetector described later included in the optical pickup head. Changes in the reflected light from the pits formed on the track are reflected, and this becomes a reproduction signal.

The data reproduction unit 321 receives a reproduction signal from the RF amplifier 317 and a reproduction clock signal from the PLL control unit 315, respectively. As for the reproduction signal, the data reproduction unit 321 reproduces the recording data based on the reproduction clock signal.

The address reproduction unit 322 receives a reproduction signal from the RF amplifier 317 and extracts address information from the reproduction signal.

Next, details of the optical pickup head will be described with reference to FIG.
The optical pickup head includes a blue laser diode 401, a polarizing beam splitter (PBS) 402 and a polarizing beam splitter 407, a quarter wave plate 403 and a quarter wave plate 408, a collimator lens 404 and a collimator lens 409, and a collimator lens actuator. 405 and a collimator lens actuator 410, a red laser diode 406, a dichroic prism 411, an objective lens 412, an objective lens actuator 413, and a photodetector IC (PDIC) 414 and a photodetector IC 415.

The blue laser diode 401 is a semiconductor laser having a wavelength of 405 nm, for example, and irradiates the recording layer of the optical recording medium 100 with a light beam for recording and reproduction.
The polarization beam splitter 402 transmits incident light from the blue laser diode 401, and reflects light reflected by the optical recording medium 100 and having a 90-degree polarization plane rotated from the incident light.

The quarter-wave plate 403 transmits incident light from the blue laser diode 401 and converts linearly polarized light into circularly polarized light. Further, the blue laser diode 401 transmits reflected light from the optical recording medium 100 and converts circularly polarized light into linearly polarized light. The linearly polarized light at this time is linearly polarized light having a 90-degree polarization plane different from that of the incident light.
The collimator lens 404 converts incident light from the blue laser diode 401 into substantially parallel light.

The collimator lens actuator 405 drives the collimator lens 404 so that the light beam of the blue laser beam that has passed through the objective lens 412 moves in the focus direction indicating the thickness direction of the optical recording medium 100. Specifically, the collimator lens 404 is driven so as to approach or move away from the facing surface of the quarter-wave plate 403.
The red laser diode 406 is a semiconductor laser having a wavelength of 655 nm, for example, and irradiates the guide layer of the optical recording medium 100 with a tracking servo beam.

The polarization beam splitter 407 transmits incident light from the red laser diode 406, and reflects light reflected by the optical recording medium 100 and having a 90-degree polarization plane rotated from the incident light.
The quarter-wave plate 408 is similar to the quarter-wave plate 403, transmits incident light from the red laser diode 406, and converts linearly polarized light into circularly polarized light. Further, the reflected light from the optical recording medium 100 of the red laser diode 406 is transmitted, and circularly polarized light is converted into linearly polarized light.

The collimator lens 409 converts incident light from the red laser diode 406 into substantially parallel light.
The collimator lens actuator 410 is the same as the collimator lens actuator 405, and drives the collimator lens 409 so that the red laser beam that has passed through the objective lens 412 moves in the focus direction indicating the thickness direction of the optical recording medium 100. . Specifically, the collimator lens 409 is driven so as to approach or move away from the facing surface of the quarter-wave plate 408.

The dichroic prism 411 transmits the incident light from the blue laser diode 401 and reflects the incident light from the red laser diode 406.
The objective lens 412 focuses the light beam emitted from the blue laser diode 401 on the recording layer of the optical recording medium 100. Further, the light beam emitted from the red laser diode 406 is condensed on the guide layer of the optical recording medium 100.
The objective lens actuator 413 drives the objective lens 412 in the focus direction so that each light beam that has passed through the objective lens 412 moves in the focus direction on the optical recording medium 100. Further, the objective lens 412 is driven so that the light beam that has passed through the objective lens 412 moves in the radial direction on the optical recording medium 100.

The photodetector IC 414 is composed of, for example, a quadrant photodetection cell, and the reflected light reflected by the polarization beam splitter 402 is detected by these photodetection cells to obtain a light reception signal. The generated light reception signal is output to the RF amplifier 317.
Similar to the photodetector IC 414, the photodetector IC 415 includes, for example, a quadrant photodetection cell, and the reflected light reflected by the polarization beam splitter 407 is detected by these photodetection cells to obtain a light reception signal. The generated light reception signal is output to the RF amplifier 317.

A blue front monitor PD (not shown) included in the optical pickup head 311 and configured by a photodiode branches a part of the laser beam generated from the laser diode 401 by a fixed ratio by a half mirror (not shown), that is, the amount of light. A light reception signal proportional to the irradiation power is detected. The blue front monitor PD supplies the light reception signal to the laser modulation control unit 316.

Further, a red front monitor PD (not shown) that is included in the optical pickup head 311 and is configured by a photodiode branches a part of laser light generated from the laser diode 406 by a certain ratio by a half mirror (not shown) to divide the light amount, that is, irradiation A light reception signal proportional to the power is detected. The front monitor PD for red supplies a red laser modulation control unit (not shown).

Next, details of the write-once control unit 307 will be described with reference to the block diagram of FIG.
The additional write control unit 307 includes an end position detection unit 501 and an additional write start position setting unit 502.
The end position detection unit 501 determines the end position of the first data when there is a recorded area related to the first data in the recording layer of the optical recording medium and new second data is recorded on the same recording layer. To detect.
The additional recording start position setting unit 502 receives the end position from the end position detection unit 501, sets the recording start position of the second data to a position that overlaps the recorded area beyond the end position, and based on the information about the recording start position. The track controller 320 and the feed motor controller 312 are controlled.

Next, a recording method of the optical recording / reproducing apparatus in the present embodiment will be described with reference to FIG.
First, the first data 601 starts to be recorded on the optical recording medium according to a normal recording procedure. That is, the servo light spot is subjected to tracking servo so as to follow the guide groove of the guide layer, and the recording spot having a different focal point on the same axis as the servo light is focused on the recording layer, and recording is performed on the recording layer. The spiral data generally following the guide track is recorded.

Here, an area where data from the end of the first data 601 up to a predetermined number of tracks is written is called a first buffer track.
When the second data 602 is appended after the first data 601 after an arbitrary time has elapsed, the data from the start of the second data 602 to the data of a predetermined number of tracks is called a second buffer track. Hereinafter, the first buffer track and the second buffer track are collectively defined as a buffer region 603.

The first buffer track and the second buffer track are overlapped in the radial direction of the optical recording medium by at least one track pitch, so that no matter how the tilt and lens shift change, there is always a boundary between data. A reproduced signal is present. As a result, tracking can be performed during continuous playback.
The data pattern recorded on the first buffer track and the second buffer track defined here may be a single pattern or a dummy mark that does not depend on a predetermined modulation method. Furthermore, if a recording method to be described later is used, the data can be a part of the first data 601 and the second data 602, or can be arbitrary data representing management information other than user data. That is, any data pattern may be used.

Specifically, the additional recording start position setting unit 502 uses, as the start position of the second data 602, a track represented by the following formula from the address indicating the end of the first data 601 obtained by the end position detection unit 501. By setting the address shifted to the recorded area (first data) by the number X as the additional recording start position, even if a tilt or lens shift different from the previous recording occurs during additional recording, the overlap is reliably realized. be able to.
The number of tracks X for realizing the overlap is the maximum possible tilt amount θ _max , the lens shift amount Ls _max , the distance d between the guide layer and the recording layer, the refractive index n of the medium, the lens shift amount and the maximum Assuming that the coefficient S and the track pitch Tp indicate the relationship with the amount of spot position deviation, the equation (1) can be obtained.

Here, X is a positive integer.
The coefficient S indicating the relationship between the lens shift and the spot position deviation amount can be derived analytically from the optical design value, or can be obtained in advance from the actual measurement value.

As described above, the number of margin tracks, which is the number of tracks that can be overlapped, may be determined for the first buffer track number A and the second buffer track number B, instead of simply overlapping. When the number of overlapping margin tracks is Y, it is determined so as to satisfy the following expressions (2) and (3).
A> 2X + Y (2)
B> 2X + 2Y (3) (X and Y are positive integers)
Next, the relationship of radial overlap in the buffer region will be described with reference to FIG.
7A and 7B show (a) when the tilt and lens shift states are not changed (Normal) and (b) when tilt and lens shift occur in the direction in which the tracks are farthest from each other (Far). ) And (c) (Near) are shown when the tracks occur in the closest direction. Here, it is assumed that the overlap margin track Y = 10.

Thus, by providing the overlap margin track Y and determining the number of first buffer tracks and the number of second buffer tracks, the start of additional data in the buffer region 603 is possible regardless of any tilt and lens shift. The position is settled. Therefore, overwriting to data tracks other than the buffer area can be completely suppressed, and necessary data can be protected.

(Modification)
As a modification of this embodiment, the first buffer track and the second buffer track may be divided in the circumferential direction of the optical recording medium, and data may be recorded intermittently. By doing so, destruction of data in the buffer track can be prevented, and readable data can be recorded in the buffer track.

The additional write control unit according to this modification will be described with reference to the block diagram of FIG.
The write-once control unit 800 according to this modification includes an angle information detection unit 801, a first timing generation unit 802, a first recording control unit 804, a second timing generation unit 803, and a second recording control unit 805.

The angle information detection unit 801 obtains angle information related to the rotation angle of the optical recording medium. The angle information may be obtained from address information obtained from the guide layer of the optical recording medium, for example. Further, if the rotation speed control method of the optical recording medium is a ZCAV (Zoned Constant Angular Velocity) method in which the rotation speed (angular velocity) is constant within a predetermined zone, angle information can be obtained simultaneously with address information. desirable. In addition, a spindle motor encoder or a rotary encoder pattern formed on the inner circumference / outer circumference of the optical recording medium may be used.
The first timing generation unit 802 receives angle information from the angle information detection unit 801. The first timing generation unit 802 turns on the adjacent angle region based on the angle information for the angle region obtained by dividing the track of the angle information recording layer into N pieces (N ≧ 2 even number) along the circumferential direction. And a first recording timing signal in which OFF is inverted is generated. Specifically, for example,
The second timing generation unit 803 receives the first recording timing signal from the first timing generation unit 802 and outputs a second recording timing signal in which at least a part of the first recording timing signal is on during the off period. Generate.
The first recording control unit 804 receives the first recording timing signal from the first timing generation unit 802. The first recording control unit 804 goes back by the number of the first buffer tracks from the end position of the first data based on the difference between the total capacity of the first data to be recorded and the recorded data capacity already recorded. The track position is detected, and the first data is intermittently recorded in the circumferential direction along the track in accordance with the first recording timing signal. Alternatively, the same effect can be obtained by recording arbitrary data intermittently in the circumferential direction along the track in accordance with the first recording timing signal after the first data recording is completed, in accordance with the first recording timing signal. can get.

The second recording control unit 805 receives the recording start position from the additional recording start position setting unit 502 and the second recording timing signal from the second timing generation unit 803, respectively. The second recording control unit 805 intermittently distributes the second data in the circumferential direction along the track in accordance with the second recording timing signal from the recording start position of the second data over the number of the second buffer tracks or more. Record.

Next, an angle region obtained by dividing the optical recording medium in the circumferential direction will be described with reference to FIG.
FIG. 9 shows an example in which one round of the optical recording medium is divided into N angular regions.
The first timing generation unit 802 alternately assigns numbers of 0 and 1 to adjacent angle regions for N angle regions. From the angle information, it is determined whether the angle area irradiated with the current recording spot is zero or one. For example, the first recording timing signal is output such that the recording off timing is zero, the recording on timing is 1 and so on.
Specifically, when N = 4 and the rotation angle of the optical recording medium is θ, the recording timing can be determined as follows.

Recognition number 0 (recording timing signal L) when 0 ≦ θ <90 degrees
When 90 ≦ θ <180 degrees, recognition number 1 (recording timing signal H)
When 180 ≦ θ <270 degrees, recognition number 0 (recording timing signal L)
When 270 ≦ θ <360 degrees Recognition number 1 (recording timing signal H)
Here, the second timing generation unit 803 outputs a signal obtained by inverting the first recording timing signal as the second recording timing signal. In the above example, when 0 ≦ θ <90 degrees, the second recording timing signal may be the recording on timing, and when 90 ≦ θ <180 degrees, the second recording timing signal may be the recording off timing.
At this time, the first recording timing signal and the second recording timing signal may overlap the recording off timing to some extent as long as the angular area of the medium indicated by the recording on timing does not overlap. That is, it is not necessary that the ratio between the recording on time and the off time is 1: 1.

Next, an example of data recording in the buffer area divided in the circumferential direction will be described with reference to FIG.
FIG. 10 shows a case where the second data 1002 is recorded after the first data 1001 is recorded, and the end portion of the first data is placed on the first buffer track 1004 in the buffer area 1003 by the recording method according to the modification. In this example, the start portion of the second data is recorded in the second buffer track 1005. The first data 1001 and the first buffer track 1004 are represented by thin lines, and the second data 1002 and the second buffer track 1005 are represented by thick lines.

The first recording control unit 804 records data according to the above-described first recording timing signal, for example, when the first recording timing signal is “H”, and stops recording when the first recording timing signal is “L”. To do. As a result, as shown in the first buffer track 704, the first data is intermittently recorded by being divided in the circumferential direction of the optical recording medium.
At the time of additional recording, the second recording control unit 804 records the second buffer track 705 so as to overlap the first buffer track 704. At this time, for example, the second recording timing signal is “H” according to the second recording timing signal. Data is sometimes recorded, and recording is stopped when the second recording timing signal is “L”.

As a result, the second buffer track 705 is intermittently recorded in an angular area where the first buffer track 704 is not recorded. As a result, the first buffer track 704 and the second buffer track 705 are overlapped in the radial direction of the optical recording medium, but the data itself forming each buffer track is accurately separated and recorded when viewed two-dimensionally. . Therefore, the data recorded in the buffer area 1003 can be recorded without being destroyed.

Next, FIG. 11 shows a schematic diagram of data divided in the circumferential direction in the buffer region of the entire optical recording medium.
The thin line in the figure is the first buffer track 1101, and the thick line in the figure is the second buffer track 1102. Although two tracks overlap in the radial direction, it can be seen that data can be recorded without duplication because the tracks are divided and recorded in a complementary manner in the circumferential direction, that is, in the rotation angle direction.

In the above example, the division number N is given as an example in the case of N = 4 for the sake of simplification of the description. However, in actuality, it is determined by the tracking servo band at the time of reproduction, the rotational speed of the optical recording medium, and the like.
As for the sampling frequency, in order to avoid the influence of the servo phase delay, it is necessary to sample the signal at a sampling frequency of 10 times or more of the servo band. That is, when the division number is N, the sampling number per rotation of the optical recording medium (N / 2), the rotational frequency R (Hz) of the optical recording medium, and the cutoff frequency F (Hz) of the tracking servo,
N> 2 × 10 × F / R (4)
It is understood that it is necessary to. On the other hand, when the signal band of the tracking error signal is K (Hz), the time required to pass through one divided angular region is equal to or more than the time constant 1 / (2πK) until the output is stabilized. Because there is a need
N <(2πK) / R (5)
And the upper limit can be determined.
For example, when R = 30 Hz, F = 4 kHz, and K = 600 kHz, N can be set within the range of the following expression (6) from the expressions (4) and (5).

2667 <N <125663 (N is an even number) (6)
(Data reproduction method according to this embodiment)
Next, a reproduction method when reproducing data recorded by the data recording method according to the present embodiment (hereinafter referred to as recording data) will be described.
The reproduction control unit according to this embodiment will be described with reference to the block diagram of FIG.
The reproduction control unit 1200 includes a timing signal generation unit 1201, a sampling unit 1202, and a switching unit 1203.
The timing signal generation unit 1201 receives the first recording timing signal from the first timing generation unit 802 and the second recording timing signal from the second timing generation unit 803, respectively. The timing signal generation unit 1201 generates a first sample timing signal for determining the first sample timing and a second sample timing signal for determining the second sample timing based on the first recording timing signal and the second recording timing signal. Generate.

The sampling unit 1202 receives the first sample timing signal and the second sample timing signal from the timing signal generation unit 1202, and receives the second tracking error signal from the RF amplifier 317, respectively. The sampling unit 1202 samples and holds the second tracking error signal based on the first sample timing signal and the second sample timing signal. As a result, a first sampled tracking error signal at the first sample timing is obtained, and a second sampled tracking error signal at the second sample timing is obtained.

The switching unit 1203 receives the first sampled tracking error signal and the second sampled tracking error signal from the sampling unit 1202. The switching unit 1203 controls the track control unit 320 by switching and outputting the first sampled tracking error signal and the second sampled tracking error signal according to the address information.

Next, a specific example of a method for reproducing recorded data will be described with reference to FIG.
As a method for reproducing the recorded data, for example, by using the DPD method, a deviation amount from the recorded data string in the buffer area can be obtained as a tracking error signal. Furthermore, when the angular region is divided in the circumferential direction, the sampling unit 1202 may alternately sample and hold in synchronization with the recording timing signal. Thus, the first sampled tracking error signal obtained from the data string forming the first buffer track in the buffer area and the second sampled tracking error signal obtained from the data string forming the second buffer track are made independent. Can get to. By obtaining the first sampled tracking error signal and the second sampled tracking error signal independently, each track can be selectively traced.

Specifically, for example, when the track is formed in a spiral shape from the inner periphery to the outer periphery, in the track section 1301, data is obtained using the tracking error signal obtained from the first data from the inner periphery to the outer periphery. Play.

Thereafter, in the track section 1302, switching to the first sampled tracking error signal is performed from the time when the data recorded in the buffer area is reproduced.
In the track section 1303, switching to the second sampled tracking error signal is performed when it is determined that the first buffer track and the second buffer track overlap in the radial direction. At this time, there is a possibility that a several track jump may occur due to the influence of the switching operation of the servo signal. However, by providing the above-described overlap margin track Y, it is possible to find the switched destination track.

In the track section 1304, when it is determined that the second buffer track is completed, the track section 1304 is switched to a tracking error signal obtained from the second data.
By performing the above-described operation, the first data to the second data can be seamlessly reproduced without stopping the servo operation, and quick data access can be realized.

According to the optical recording / reproducing apparatus according to the present embodiment described above, the buffer area is formed by overlapping the end of the first data and the start of the second data as additional recording data in the radial direction of the optical recording medium by several tracks. By doing so, it is possible to continuously apply the tracking servo during reproduction even in a tilt state different from the time when the previous data was recorded during additional recording. Therefore, data access can be easily performed during reproduction. Further, the buffer track forming the buffer area is divided into a plurality of areas along the circumferential direction, and the first data and the second data as additional data are alternately recorded in the circumferential direction, so that the existing data The desired data can be recorded even in the buffer area without being overwritten, and the data can be easily accessed during reproduction.

Note that the optical recording medium can be applied to the rewritable phase change type recording method according to the present embodiment, and the write-once type medium is more necessary for additional writing. In particular, the recording method according to the present embodiment is particularly effective.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 100 ... Optical recording medium, 101 ... Guide layer, 102 ... Recording layer, 103 ... Guide light, 104 ... Recording light, 100 ... Optical recording medium, 201, 202 ... Track position, 300 ... optical recording / reproducing apparatus, 301 ... CPU, 302 ... interface, 303 ... RAM, 304 ... NV-RAM, 305 ... ROM, 306 ... error Correction unit, 307, 800 ... additional write control unit, 308 ... spindle motor control unit, 309 ... spindle motor, 310 ... rotary encoder, 311 ... optical pickup head, 312 ... motor control , 313... Motor, 314... Screw shaft, 315... PLL control section, 316... Laser modulation control section, 317. Collimator lens actuator control unit, 319... Focus control unit, 320... Track control unit, 321... Data reproduction unit, 322... Address reproduction unit, 350. Signal bus 401 ...

Blue laser diode

402, 407 ... Polarizing beam splitter, 403, 408 ... Quarter wave plate, 404, 409 ... Collimator lens, 405, 410 ... Collimator Lens actuator, 406 ... red laser diode, 411 ... dichroic prism, 412 ... objective lens, 413 ... objective lens actuator, 501 ... end position detector, 502 ... additional write start position setting Part, 601 ... first data, 602 ... second data, 603 ... buffer area, 7 4 ... 1st buffer track, 705 ... 2nd buffer track, 801 ... Angle information detection part, 802 ... 1st timing generation part, 803 ... 2nd timing generation part, 804 ... First recording control unit, 805 ... second recording control unit, 1001 ... first recording data, 1002 ... second recording data, 1003 ... buffer area, 1004, 1101 ... first Buffer track, 1005, 1102 ... second buffer track, 1200 ... reproduction control unit, 1201 ... timing signal generation unit, 1202 ... sampling unit, 1203 ... switching unit, 1301, 1302, 1303 , 1304... Track section.

Claims

An optical recording / reproducing apparatus for recording data on a recording medium in which one or more recording layers on which data is recorded and a guide layer used for positioning are separated from each other,
An end position detection unit for detecting an end position of the first data when there is a recorded area relating to the first data in the recording layer of the recording medium and new second data is recorded on the recording layer; ,
An optical recording / reproducing apparatus, comprising: an additional recording start position setting unit that sets the recording start position of the second data to a position that overlaps the recorded area from the end position.
An angle information detector for obtaining angle information related to the rotation angle of the recording medium;
A first recording timing signal is generated that divides a track of the recording layer into angular regions along the circumferential direction by an even number of 2 or more, and that turns on and off in adjacent angular regions based on the angle information. A timing generator;
When recording the first data, the track is recorded along the track of the recording layer in accordance with the first recording timing signal from the position of the track recorded after the first track number from the end position of the first data. A first recording controller for intermittently recording the first data in the circumferential direction;
A second timing generation section for generating a second recording timing signal in which at least a part of the first recording timing signal is turned off,
When recording the second data, the second data is recorded along the tracks of the recording layer according to the second recording timing signal from the recording start position of the second data over the number of tracks equal to or greater than the second number of tracks. The optical recording / reproducing apparatus according to claim 1, further comprising: a second recording control unit that intermittently records the data in the circumferential direction.
3. The optical recording / reproducing apparatus according to claim 2, wherein the angle information detection unit obtains the angle information from address information of the guide layer.
The optical recording according to any one of claims 1 to 3, wherein the rotation control method of the recording medium is a ZCAV (Zoned Constant Angular Velocity) method in which the number of rotations is constant in a zone. Playback device.
The first track number and the second track number are:
Number of first tracks> 2X + Y
Number of second tracks> 2X + 2Y
The first track number and the second track number are positive integers, and X is

Where Y is the number of margin tracks representing the overlap of the first track and the second track and is a positive integer, θmax is the assumed maximum tilt amount, and Lsmax is The maximum lens shift amount assumed, d is the distance between the guide layer and the recording layer, n is the refractive index of the recording medium, and S is the lens shift amount and the maximum spot position deviation amount. 5. The optical recording / reproducing apparatus according to claim 2, wherein Tp is a track pitch.
When the number of divisions of the angle area is N (N is a positive integer), N satisfies N> 20 × F / R, R is the rotation frequency of the recording medium, and F is the servo cutoff frequency. The optical recording / reproducing apparatus according to claim 2, wherein the optical recording / reproducing apparatus is one of the following.
The additional recording start position setting unit moves the recording start position from the end position in a direction overlapping the recorded area of the first data.

Is set to a position moved by a distance X or more determined by (2), X is a positive integer, θ max is an assumed maximum tilt amount, Ls max is an assumed maximum lens shift amount, d is the distance between the guide layer and the recording layer, n is the refractive index of the recording medium, S is a coefficient indicating the relationship between the lens shift amount and the maximum spot position deviation amount, and Tp is the track 5. The optical recording / reproducing apparatus according to claim 1, wherein the optical recording / reproducing apparatus is a pitch.
An optical recording / reproducing apparatus for reproducing the data from an optical recording medium in which one or more recording layers on which data is recorded and a guide layer used for positioning are separated from each other,
An optical pickup head that receives reflected light of a beam irradiated on the optical recording medium and generates a light reception signal based on the received light;
Based on the light reception signal, an error signal generation unit that generates a tracking error signal between the recorded data position and the beam spot position;
Based on the first recording timing signal in which ON and OFF are inverted, at least a part of the first sample timing signal for determining the first sample timing and the period in which the first recording timing signal is OFF is ON. A timing signal generator for generating a second sample timing signal for determining a second sample timing based on the second recording timing signal,
The tracking error signal is sampled and held based on the first sample timing signal and the second sample timing signal, and the first sampled tracking error signal at the first sample timing and the second sampled tracking at the second sample timing A sampling unit for obtaining an error signal;
Switching is performed according to the first sampled tracking error signal and the second sampled tracking error signal, the first data is obtained according to the first sampled tracking error signal, and the first data is obtained according to the second sampled tracking error signal. An optical recording / reproducing apparatus comprising: a switching unit that obtains two data.
An optical recording / reproducing method for recording data on a recording medium in which one or more recording layers on which data is recorded and a guide layer used for positioning are separated from each other,
When there is a recorded area related to the first data in the recording layer of the recording medium, and the second data is newly recorded on the recording layer, the end position of the first data is detected,
An optical recording / reproducing method, wherein the recording start position of the second data is set to a position overlapping the recorded area from the end position.
An optical recording / reproducing method for reproducing the data from an optical recording medium in which one or more recording layers on which data is recorded and a guide layer used for positioning are separated from each other,
Receiving reflected light of the beam irradiated on the optical recording medium, and generating a light reception signal based on the received light;
Based on the received light signal, a tracking error signal between the position of the recorded data and the spot position of the beam is generated,
Based on the first recording timing signal in which ON and OFF are inverted, at least a part of the first sample timing signal for determining the first sample timing and the period in which the first recording timing signal is OFF is ON. A second sample timing signal for determining a second sample timing based on the second recording timing signal,
The tracking error signal is sampled and held based on the first sample timing signal and the second sample timing signal, and the first sampled tracking error signal at the first sample timing and the second sampled tracking at the second sample timing Get error signal,
Switching is performed according to the first sampled tracking error signal and the second sampled tracking error signal, the first data is obtained according to the first sampled tracking error signal, and the first data is obtained according to the second sampled tracking error signal. An optical recording / reproducing method characterized in that two data are obtained.