JP2008269738A - Optical disk device and method on recording optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology which records, in real time, stream data supplied from the outside to an optical disk even if the optical disk has defects. <P>SOLUTION: An optical disk device is provided with; an optical pickup 16 which consecutively records data along track grooves provided on an optical disk 17; a recording/reproduction processing part 15; and a control part 12. The defects of the optical disk 17 are detected by the control part 12. When detecting the defects, the control part 12 makes control so that data are consecutively recorded while avoiding prescribed ranges which have certain distances in the radius direction from the positions at which the defects are detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical disc apparatus and an optical disc recording method.

  Conventionally, rewritable type (rewritable / RW type) and write once type (write once / R type) optical discs that allow users to freely record data, and optical disc devices corresponding to these are widely used. ing.

Also, for the purpose of further increasing the recording capacity, a Blu-ray disc (Blu-ray disc) that uses blue laser light (wavelength 405 nm) shorter than conventional CD (Compact Disc) and DVD (Digital Versatile Disc) is used. Disc) (registered trademark) has also been developed, and there are rewritable BD-RE and write-once BD-R on Blu-ray discs.
JP 2006-59395 A JP 2005-302163 A

  By the way, in recent years, video recording apparatuses such as stationary video recorders and video handy cameras, which are designed to record video on an optical disc, are widely used instead of the conventionally used magnetic tape. In a video recording apparatus using such an optical disc, it is necessary to record video data supplied from the outside and stream data of the video being shot on the optical disc in real time.

  In the above-described real-time recording of stream data on the optical disc, stream data to be recorded is continuously supplied. Therefore, even when a recording error occurs, recording interruption due to the error is not allowed, and the stream data is interrupted. It is required to record so that it can be played back without being performed.

  FIG. 8 is a diagram schematically showing a recording procedure. In order to deal with such a request, for example, as shown in FIG. 8A, stream data is recorded at an error address A during real-time recording on a write-once optical disc. When a recording error occurs, there is a method of continuing to record stream data from the error address A as shown in FIG. In this case, the recorded stream data is continuous before and after the occurrence of an error as shown in FIG. Also, if the length of error occurrence is within a range that can be corrected by ECC (Error / Correction / Code), there will be no major problem in the recording / reproducing operation. However, if the cause of the recording error is caused by a bubble, the recording error becomes bursty and exceeds the correctable code length of the ECC, so that it is no longer possible to recover by the ECC. There is.

  Here, the bubble is a kind of defect of the optical disc, and air is mixed in the injection process at the time of manufacturing the optical disc, and the air remains between the recording layer and the surface of the protective layer after the optical disc is formed. This is what happens. This bubble is the most common cause of optical disk defects, particularly in Blu-ray Discs.

  An object of the present invention is to provide a technique for recording stream data such as video supplied from the outside on an optical disc in real time without causing a stagnation in the recording operation even when the optical disc is defective. Yes.

  An optical disc apparatus according to the present invention includes a recording means for continuously recording data along a track groove provided on an optical disc, an optical disc defect detecting means for detecting a defect of the optical disc, and a position after the position where the defect is detected. Control means for controlling the recording means so as to continuously record the data while avoiding a predetermined range at a certain distance in the radial direction.

  The optical disc apparatus of the present invention has recording means and continuously records data along the track grooves. In addition, an optical disk defect detecting means is provided to detect an optical disk defect. Further, since the recording means is controlled so as to continue the data recording while avoiding a predetermined range at a certain distance in the radial direction after the position where the defect is detected with the control means, the stream data is interrupted. You can record without.

  The optical disk recording method of the present invention irradiates a light spot along a track groove provided on the optical disk, detects a defect of the optical disk by return light from the optical disk, and a radius after the position where the defect is detected. The recording of the data is continuously continued along the track groove while avoiding a predetermined range at a certain distance in the direction.

  In the optical disk recording method of the present invention, the light spot is irradiated so as to follow the track groove provided on the optical disk. Further, the defect of the optical disk is detected by the return light from the optical disk. When a defect on the optical disk is detected, data recording can be continuously continued along the track groove while avoiding a predetermined range at a certain distance in the radial direction after the position where the defect is detected.

  According to the technology of the present invention, even when an optical disc has a defect, stream data such as video supplied from the outside can be recorded on the optical disc in real time without causing a stagnation in the recording operation.

  The gist of the best mode for carrying out the invention will be described, and then the detailed description will be given with reference to the drawings.

  The optical disc apparatus of the embodiment includes a recording unit that continuously records data along a track groove provided on the optical disc. Here, in the embodiment, an optical pickup (more strictly speaking, a component related to the recording operation of the optical pickup), a recording / reproduction processing unit (recording / reproduction processing unit), which are components of an optical disk device to be described later. A component related to the recording operation) and a component (including information stored in the RAM, ROM, and nonvolatile memory, and processing procedure) that control the recording operation of the control unit function as an embodiment of the recording unit. Also provided is an optical disc defect detection means for detecting a defect of the optical disc. Here, in the embodiment, a servo signal detection unit / physical sector detection unit (particularly a configuration unit that detects a signal corresponding to the return light) and a related configuration unit that is connected to the DSP of the control unit via a bus line are described below. It functions as an embodiment of the optical disk defect detection means. When a defect of the optical disk is detected, a control means for controlling the recording means so as to continue the data recording while avoiding a predetermined range at a certain distance in the radial direction after the position where the defect is detected. Is provided. Here, in the embodiment, a constituent unit that controls the DSP and CPU of the control unit, which will be described later, functions as an embodiment of the control unit. With such a configuration, even when there is a defect in the optical disk having a radial extension in the optical disk, the recording characteristic is not harmed by the defect in the optical disk, and there is a certain distance in the radial direction on the optical disk. Stream data (continuous time-series data) can be recorded without being interrupted physically avoiding a predetermined range.

  In the optical disk recording method of the embodiment, a light spot is irradiated along a track groove provided on the optical disk. Then, the defect of the optical disk is detected by the return light from the optical disk. Here, when detecting a defect, any one of a tracking signal, a focus signal, a sum signal, or an appropriate combination thereof can be adopted as a signal corresponding to the return light from the optical disc. When a defect on the optical disk is detected, physically, data recording is continuously continued along the track groove while avoiding a predetermined range at a certain distance in the radial direction after the position where the defect is detected. Thus, stream data can be recorded on the optical disc continuously in time.

  In order to improve the recording capacity, the optical disk used here is recorded with a constant surface density, and with a constant spacing between adjacent track grooves, a recording with a constant linear density is performed along the track grooves. Has been made. A recording area divided into sector units along the track groove is defined as one logical sector which is an ECC completion unit. The optical disc of the embodiment may have physical sectors that are preformatted and given physical addresses to the respective areas, and recording may be performed in units of the physical sectors. In this case, the physical length of the physical sector and the logical sector may be substantially the same length. An example of such an optical disc is a Blu-ray disc. Hereinafter, when it is not necessary to distinguish between a physical sector and a logical sector, the term “sector” is sometimes used.

  Since the number of sectors included in the predetermined range at a certain distance in the radial direction from the position in the radial direction of the optical disc where the defect is detected differs depending on the radial position, the control means is configured to detect the optical disc in the radial direction of the optical disc. The number of sectors included in a predetermined range at a certain distance in the radial direction from the position of is determined, and data recording is continued continuously avoiding the range of the number of sectors determined from the sector at the position where the defect is detected. You may do it. In this way, when there is no defect on the optical disc, the sectorized stream data continues in the order of the physical address numbers given continuously along the track groove between the inner circumference and the outer circumference of the optical disc. When a defect in the optical disc is detected, the physical address numbers that are not in the physical address number order and the range in which the recording / playback function is impaired by the defect are skipped (to avoid without recording) Thereafter, recording is performed again in the order of physical address numbers.

  In addition, since it is cumbersome to calculate the number of sectors included in the predetermined range according to the radial position for each radial position, the following is performed in order to eliminate this complexity and increase the load on the apparatus and the processing speed. You may do it. First, the optical disc has a plurality of areas classified in advance according to the size of the radius. Here, the plurality of areas do not have physical boundaries, but are virtually determined by physical addresses previously assigned to the optical disc (for example, sector numbers continuously given from the inner circumference side to the outer circumference side of the optical disc). The regions may be separated. The control means includes area determination means for determining which of the plurality of areas the position in the radial direction of the optical disc where the defect is detected belongs, and a predetermined number of sectors determined in accordance with the corresponding area The data recording may be continued continuously while avoiding the above. Here, in the embodiment, a RAM, a ROM, or a non-volatile memory connected to a DSP of a control unit that detects a physical address, which will be described later, and a CPU of a control unit that stores a physical address at the boundary of each region in advance is an area. It functions as one embodiment of the judging means.

  When the defect of the optical disc is a bubble, the maximum size of the bubble is statistically known, and therefore, it can be specified that the predetermined range in the radial direction is within a certain range. Application to this bubble is easy. Further, in the inspection process, the technique shown in the embodiment can be used in that the optical disk having a bubble of a predetermined distance or more in the radial direction can be excluded and the bubble hardly occurs later after the production. It can be effectively implemented. However, the defect of the optical disk to which the technology of the embodiment can be applied is not limited to the bubble, but can be similarly applied to the defect of the optical disk extending in the radial direction, and the effect can be exhibited.

  Hereinafter, embodiments will be described in more detail with reference to the drawings.

(About bubble)
First, the generation of bubbles and the influence of the bubbles on the recording / reproduction characteristics will be described very simply. The generation of a bubble is a phenomenon that occurs when an optical disc is formed using an injection process. Bubbles contained in the melted resin remain between the recording layer and the surface of the protective layer on the light incident side after molding, forming bubbles. This bubble has a substantially circular shape and is not related to the inner and outer circumferences of the optical disc, and its size is a maximum of 50 μm (micrometer) according to the inventor's observation described in the application of the present application. Degree. Further, the generation positions of the bubbles are distributed almost randomly from the inner periphery to the outer periphery. In addition, although the storage capacity is reduced by this bubble, the number and position of bubbles are managed in the inspection process after manufacturing the optical disk so that a sufficient recording capacity can be secured, and the bubble exceeds the specified range. The optical disc having the above is excluded in the inspection process.

  This bubble has a great influence on the recording / reproducing characteristics because the recording / reproducing spot exists inside the protective layer and the recording layer, which are areas where the diameter is sufficiently small. That is, in the range of the recording layer that is covered by the bubble, the recording / reproducing characteristics are impaired, making it difficult to record and reproduce information.

(Relationship between disk format and bubbles)
The relationship between the above-described bubble and the format of the optical disc of the embodiment will be briefly described. As described above, the bubbles have a diameter of 50 μm. On the other hand, on the optical disc, track grooves are continuously formed in a spiral shape between the innermost periphery and the outermost periphery. In this embodiment, the track groove interval is, for example, about 0.32 μm. Recording / reproduction is performed along the track groove in accordance with a recording format having a constant linear density. As the linear density, for example, about 2.24 mm / Sector (millimeter / sector) is adopted in the embodiment. That is, the stream data to be recorded is divided into sectors every 2.24 mm along the track of the optical disc as a minimum unit, and ECC is added to each sector. As described above, when the track groove is 0.32 μm, when the bubble diameter is 50 μm, the influence of the bubble is exerted on approximately 157 tracks.

(About skip processing overview)
An outline of the skip processing employed in the embodiment will be described with reference to FIGS. 1, 2, and 3. In this specification, the term “skip processing” refers to an area in which recording is performed in another recording area without recording in a recording area where inconvenience occurs in recording, and such processing is performed in reproduction. Is used as a term meaning a process of reproducing without reading information. The meaning of this term will be clarified by the explanation given below. FIG. 1 shows the positional relationship between track grooves and bubbles of an optical disc. An example of skip processing will be described below with reference to FIG. In FIG. 1, stream data to be recorded is continuously supplied and recorded sequentially from the inner periphery to the outer periphery of the optical disc. When the bubble 30 is detected at the nth position P11 of the track and the point where the bubble is not detected is set as the position P12, the recording is stopped after the bubble is detected at the position P11, and the position P12 is not included. It is conceivable to continue recording from the beginning of the next sector S (n) 2. When such a recording method is adopted, since the bubble is detected again at the position P13 due to the presence of the bubble 30, the recording is temporarily stopped and the sector S (n + 1) in which the position P14 is not included. Continue recording from the beginning of 2. The same processing is repeated for each rotation of the optical disc. At the track n + (m−1) th, the recording is temporarily stopped at the position P1 (2m + 1), and the sector S (n + m−) in which the position P1 (2m + 2) is not included. 1) Recording is continued again from the beginning of 2. Further, at the track n + mth, recording is temporarily stopped at the position P1 (2m + 3), and from the beginning of the sector S (n + m) 2 where the position P1 (2m + 4) is not included. It will continue to record again. Note that how to detect bubbles will be described later. Further, the head position of each sector can be detected based on a physical address based on a signal preformatted on the optical disk. In the above description, the recording on the optical disk is described as being performed along the spiral track continuously from the inner peripheral side to the outer peripheral side.

  When such skip processing is employed, there is a problem that skip processing frequently occurs. In the lowest level processing closely related to hardware control, what kind of processing is performed is an arbitrary matter of design, but the physical address address where skip processing occurred is stored and skip processing was performed. It is also possible to further store the previous physical address and optimize the processing of the area where the skip processing is performed by so-called seek processing. In such a case, the physical address address to be stored requires a set of a skip source address (a point at which skip processing is started) and a skip destination address. For example, when the skip process of the example shown in FIG. 1 is performed, the number of physical addresses is (m + 1) × 2. Further, for example, the time between the position P11 and the position P12 is smaller than the loop time constant of each servo (reciprocal of the servo band), so that the servo operation is not directly affected. The time between P13 and the position P14 becomes longer, and as it approaches the center of the bubble, the operation of each servo is adversely affected, and the focus servo and tracking servo or tracking servo may not function due to the bubble. There is. In this case, a procedure for operating a series of servos starting from the focus search must be performed, and then the physical address of the skip destination must be accessed by the seek operation. The maximum number of servo procedures and seeks required is m. Times.

  Further, when a light spot is irradiated on the bubble 30 in the middle of a seek and crosses this, the servo may again malfunction, and it may take a long time to reach a desired physical address. When such processing is repeated while stream data to be recorded is continuously supplied, the data of the portion where recording has been delayed must be stored in a large buffer memory. As a result, the price of the apparatus increases, servo processing and skip processing become complicated, and the recording characteristics, particularly the recording transfer rate, decrease, which is not preferable.

  Here, as described above, the length of the bubble 30 along the track direction is closely related to the recording characteristics. For example, at the initial stage of detecting the bubble 30, the separation distance between the position P11 and the position P12 is small. Further, as described above, the time from the position P11 to the position P12 is shorter than the loop time constant of each servo, so that there is no abnormality in the servo system, and there is an error in the recorded data. Even if it occurs, the error is corrected by the action of the ECC, and the recorded data can be completely reproduced. However, as the length of the bubble 30 along the track direction becomes longer, the operation of the servo system becomes abnormal, and the recording characteristics deteriorate so much that correction by ECC is impossible.

  Therefore, in the embodiment, skip processing for improving this is adopted. FIG. 2 shows the positional relationship between the track grooves and the bubbles of the optical disk as in FIG. With reference to this figure, an outline of the skip processing of the embodiment will be described. In the skip processing of the embodiment, the range indicated by the oblique lines in FIG. 2 is characterized in that the recording area is excluded from the beginning, that is, skipped. When the bubble 30 is detected at the position P21, the area to be excluded is from a track adjacent to the track to which the position P21 belongs to a track 50 μm away from which the probability that a bubble exists is low. That is, the tracks are 157 tracks apart on the outer peripheral side. In addition, in order to reach a recordable track separated by 157 tracks, a spiral track is not traced to reach the recordable track while performing normal tracking servo, but the recordable track is reached by a seek operation. To do. At this time, when the seek operation is started immediately from the position P21 where the bubble is detected, the light spot reaches the position P22 via a trajectory connecting the position P21 and the position P22 shown in FIG. In this case, since the light spot crosses over the bubble 30, it is impossible to obtain a focus signal and a traverse signal (track cross signal), which are necessary information during the seek, and the seek operation is proper. It may be harmed to be done. Therefore, in the embodiment, the seek operation is started from the position P′21 away from the bubble, the seek operation is stopped at the position P′22 along the locus indicated by the one-dot chain line, the track king servo is turned on, and the recording is performed. Find the physical address that should be done. The position P′21 is determined as appropriate depending on the number of rotations of the optical disk, the size of the bubble, the seek speed, the processing time until the seek command is issued, and the like.

  The servo can be turned on at any time when it is necessary to maintain the focus servo state and turn on the tracking servo without being affected by the bubble 30. Further, in the seek operation, it is possible to accurately calculate the number of traversing tracks (traverse) so that the light spot does not cross the bubble 30 and reach a desired physical sector at high speed. When such a method is adopted, the shaded area shown in FIG. 2 is discarded without being used for recording / reproduction, but the number of bubbles in one optical disk is equal to or less than the prescribed number. In this case, the reduction of the recording capacity by this falls within a predetermined range and does not become a big problem.

  For example, description will be given with reference to FIG. The physical address from the physical address (physical sector) S (n) 1 to which the position P′21 belongs to the physical address S (n + m−1) 2 that is the physical address number to which the position P′22 belongs is skipped, and the next Resuming recording from the physical address S (n + m−1) 3 can reduce the number of sectors to be skipped most. In this case, how the number of sectors to be skipped is derived as a general formula below. . FIG. 3 schematically shows the relationship between the physical address and the radius. First, with reference to FIG. 3, the derivation of the equation indicating the relationship between the physical address N and the radius R will be described. It is assumed that the physical address number (described as PSN in FIG. 3) at a point with a radius of 24 mm is 100,000 h (hex display). In this case, if the radius at the point of the physical address number N is R, the relationship between the physical address number N and the radius R is expressed by equation (1).

  πxRxR? πx24mmx24mm = (N-100000H) x (1Sector length) x (track interval) ... (1)

  When the number of sectors to be skipped is M, the radius of this starting point position is R, and the radius of the target position, which is the target position, is R + L, Equation (2) is established.

  πx (R + L) x (R + L)? πx24mmx24mm = (N + M-100000h) x (1Sector length) x (track interval) ... (2)

  From equation (1), the radius at the physical address number N is obtained by equation (3).

  R = {((N-100000h) x (1 Sector length) x (track interval) + πx24 mmx24 mm) / π} 1/2 (3)

  Using the result of equation (3), equation (2) can be solved to obtain equation (4).

  M = πx (2xRxL + LxL) / {(1 Sector length) x (track interval)} (4)

  For example, when selecting the maximum bubble diameter of 50 μm as the value of L, as an example, in a one-recordable Blu-ray disc with a capacity of 25 GB (Giga · Byte), 1 Sector length is 2.24 mm and the track pitch is It is calculated from 0.32 μm. In the vicinity of the outermost periphery of the optical disk, the physical address number is CA7400h, so the range of the area (skip area) included in the shaded area in FIG. 2 has the number of physical sectors of 6360h. That is, it is necessary to skip without recording in the physical sector of 6360h. On the other hand, since the physical address is 100000h in the vicinity of the innermost circumference of the optical disk, it can be seen from the above calculation that the skip area has 2920h physical sectors. In other words, in order to set the diameter of the bubble 30 to 50 μm and completely skip it, it is impossible to record in the above-mentioned number of physical sectors near the innermost periphery and the outermost periphery of the optical disc. Hereinafter, the outline of the optical disk apparatus of the present embodiment will be briefly described, and how the skip process of the embodiment is performed in this optical disk apparatus will be specifically shown.

(About the outline of the optical disk device)
FIG. 4 is a diagram showing an outline of the configuration of the optical disc apparatus. In FIG. 4, only the main part of the optical disc apparatus 10 necessary for the description of the embodiment is shown, and other parts that are not important in the description of the embodiment are omitted. In the embodiment, the optical disc 17 is a Blu-ray disc. The control unit 12 controls the entire optical disc apparatus 10, and controls the recording / reproducing system, the servo system, and the interface with an external device. The servo signal detection unit / physical address detection unit 13 receives a signal from the optical pickup 16 to detect a sur signal, and detects a physical address number assigned to each pre-formatted physical sector. The servo drive unit 14 is controlled by the control unit 12 and controls a focus actuator and a tracking actuator (not shown), and also controls a thread feed motor 19 and a spindle motor 18.

  The control unit 12 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a non-volatile memory that are connected to each other via a first bus line. Yes. The control unit 12 includes a DSP (Digital Signal Processing Processor), an A / D (Analog to Digital) converter, a D / A (Digital to Analog) converter, which are connected to each other via a second bus line. A RAM (Random / Access / memory), a ROM (Read / Only / Memory), and a non-volatile memory are connected to each other via a bus line. The CPU and the DSP are connected to each other via respective interface terminals to enable communication. The CPU mainly performs overall control of the optical disk device 10, recording / reproduction processing, and interface processing with an external device. The DSP directly exchanges signals with the servo signal detection unit / physical address detection unit to control the servo system. Controls the seek operation.

  In recording, stream data to be recorded input from the external device to the optical disc apparatus 10 is output to the recording / reproduction processing unit 15 via the control unit 12, and the recording / reproduction processing unit encodes the ECC process. Is processed. Information corresponding to the stream data is recorded on the disc by modulating the laser beam of the optical pickup 16 according to the encoded data (channel data). In reproduction, the signal detected by the optical pickup 16 is subjected to decoding processing including ECC processing in the recording / reproduction processing unit 15 and is controlled as a signal of a predetermined format such as NTSC (National / Television / Committee). The data is output to an external device via the unit 12. The control of the processing described above is mainly performed by the CPU of the control unit 12, and the physical address detected from the servo signal detection unit / physical address detection unit 13 is referred to whenever the CPU performs these processings.

  The recording / playback processing unit 15 performs an encoder for converting the data format from the control unit into a channel format, a decoder for converting the channel format into a data format for the control unit, encoding, ECC code addition at the time of decoding, and error correction processing. An ECC unit is provided. Furthermore, a PLL (Phase / Locked / Loop) for reproducing the channel clock is also provided. Further, the recording / reproduction processing unit 15 combines the transfer rate of recording on the optical disc 17 with the transfer rate of stream data to be recorded supplied from the control unit 12 and supplies it to the control unit 12 in recording / reproduction. A buffer memory is provided for matching the transfer rate of the reproduced data to be reproduced with the transfer rate (transfer rate) reproduced from the optical disc 17. The buffer memory is controlled by different clocks (dual clocks) for writing and reading, and absorbs the difference between the transfer rate of recording / reproduction on the optical disc 17 and the transfer rate of the control unit 12 and thus the external device, It functions as a FIFO (First / In / First / Out) memory. Here, except when an abnormal situation in which writing is stopped due to the influence of the bubble 30 occurs, the transfer speed of recording / reproduction on the optical disc 17 is larger than the transfer speed between the external device and the control unit 12. It is made to have.

  The servo signal detector / physical address detector 13 calculates a signal from the optical pickup, detects a focus signal by, for example, an astigma method, and detects a tracking signal by, for example, a DPP (Differential / Push / Pull) method The physical address is detected based on the signal from the prepit. Each of the focus signal and the tracking signal is subjected to processing for optimizing the servo system operation such as phase compensation by the DSP of the control unit 12, and the signal subjected to this processing is power amplified by the servo driving unit 14, Servo is applied to a focus actuator and tracking actuator (not shown). The low frequency component of the tracking signal is extracted by the DSP, the power is amplified by the servo drive unit 14 and applied to the thread feed motor, and the thread feed servo for the low frequency component of the tracking signal is performed. In addition, the spindle motor 18 is controlled based on the clock signal detected from the wobbling component of the pregroove of the optical disc 17, so-called CLV (Constant, Linear, Velocity) control is performed, and the optical disc rotates at a constant linear velocity. .

(About bubble detection method in optical disc apparatus)
The detection of the bubble 30 is performed by a calculation process inside the DSP. FIG. 5 shows an example of the waveform of the tracking signal TE detected from the servo signal detection unit / physical address detection unit 13, and it is A / D converted and handled as a digital value inside the DSP. The DSP determines whether the tracking signal has exceeded a positive threshold Th1. In this case, it may be determined whether or not the time Ts exceeds a predetermined time at the same time, and it may be determined that the bubble is a bubble only when the time Ts exceeds the predetermined time. In this way, it is possible to prevent short pulses generated by dust on the optical disk and scratches on the optical disk from being considered as an influence of the bubble 30. Since the tracking signal is detected by utilizing the diffraction principle of the light beam, the bubble 30 causes diffraction abnormality of the light beam, and the tracking signal TE has such a waveform. Further, it is determined whether or not the negative threshold Th2 has been exceeded, and in this case, it is determined whether or not the time Ts has been exceeded. This is because the tracking signal TE for detecting the bubble 30 may be in a negative direction depending on the diffraction method. Then, it is determined that the bubble 30 has been detected when either the above-described positive direction or negative direction tracking signal TE is detected.

  The bubble 30 may be detected not only from the tracking signal but also from the sum signal or from the focus error signal. Since the sum signal is also obtained using the diffraction principle, the influence of the bubble 30 is also exerted on the focus signal by the stigma method for detecting the difference signal from the detectors arranged diagonally under the influence of the bubble 30. Because it receives. Furthermore, it goes without saying that the bubble 30 can be detected by appropriately combining these signals.

(About skip processing of the embodiment)
Here, a recording method of the write-once Blu-ray disc will be described. Blu-ray discs use a recording mode called SRM (Sequential Recording Mode) when recording continuous data such as stream data. In this SRM, an area called SRR (Sequential Recording Ranges) is formed on the optical disk, and data is continuously recorded in the SRR. This SRR can be arbitrarily split (divided) to form a new SRR, and for SRRs that do not record any more data, the status is changed from recordable “open” to recordable “closed” and recorded. Has been made to be prohibited.

  By the way, when the SRR is split or closed as described above, it is necessary to record information to that effect in the management area of the optical disc. In the Blu-ray Disc, information such as the position and status of each SRR (closed or open), recordable address in each SRR (this is called NWA (Next / Writable / Address)), etc. are stored in the lead-in area on the inner circumference. The data is recorded in a table called SRRI (Sequential Recording Ranges Information) in the provided TDMS (Temporary Disc Management Management Structure).

Hereinafter, the procedure (skip process) of the recording method will be described with reference to FIG.
(Step 1) The CPU of the control unit 12 of the optical disc device 10 records the stream data input from the external device on the open SRR #n in the optical disc 17, and the DSP of the control unit 12 Monitor the signal indicating the occurrence.
(Step 2) The DSP detects the occurrence of a bubble (see FIG. 6A). Then, the CPU is notified of the occurrence of the bubble, and the CPU performs splitting at the address B that is a predetermined address away from the error address A, as shown in FIG. 6B, and a new SRR # n + 1 starting from the address B. And the SRR # n up to the address B is closed, and the head address (address B) of the new SRR # n + 1 is stored in the nonvolatile memory of the control unit 12.
(Step 3) The CPU restarts the recording of the stream data from the head address B of the newly formed SRR # n + 1 as shown in FIG. 6C, and periodically stores the NWA in the nonvolatile memory. When a recording end command is received from the external device, recording of stream data on the optical disc 17 is stopped accordingly.
(Step 4) After updating the SRRI of the optical disc 17, the CPU rewrites the file entry of the optical disc 17 so that the stream data recorded by being divided into SRR #n and SRR # n + 1 is logically continuous, The stream data recording process is terminated. At the time of reproduction, by using the file entry information of the stream file in this way, the portion where the data is divided can be read, and the stream data recorded on the optical disc 17 can be read continuously without interruption.

In the process of (Step 2) described above, the DSP detects the occurrence of a bubble. In this case, how to perform the lowest level process closely related to the hardware control depends on the optical disc. This is a matter related to the design of the device 10 and can be determined appropriately. For example, it is performed by controlling each part of the optical disc apparatus 10 by the DSP as follows.
(Step 11) The DSP of the control unit 12 detects the bubble 30.
(Step 12) The DSP (or CPU) recognizes the physical address of the stream data being written at the time when the bubble 30 is detected, and stores it in the RAM, for example.
(Step 13) The DSP (or CPU) calculates a physical address to be separated from the current physical address using the above-described equations (1) to (4). In this case, it is desirable to substitute a value of 50 μm or more as the value of L in Equation (4). The larger the value of L, the higher the effect of avoiding the bubble 30 and the more stable the seek operation. .
(Step 14) The DSP (or CPU) calculates the target physical address by adding the calculated physical address value to be separated to the current physical address. Further, the target physical address is stored in the RAM.
(Step 15) The DSP starts a seek after a predetermined time that does not cross the bubble, and issues a seek command to access the target physical address.
(Step 16) The DSP controls the tracking actuator to perform track jump, calculates the number of track jumps, and after a predetermined number of track jumps, the physical address and tracking signal from the servo signal detector / physical address detector 13 Dependent on the tracking servo to the target physical address.

(Modification of the embodiment)
In the embodiment described above, the number of physical addresses to be accurately skipped (the number of skip sectors) is calculated using Expressions (1) to (4). The number of skip sectors is the same in each area, and the value of the number of skip sectors required in each area is calculated in advance, and this calculation is performed in advance when skip processing is actually required. It is a modification of the embodiment that employs the number of skip sectors.

  By adopting such a method, it is not necessary for the CPU (or DSP) to calculate the equations (1) to (4) every time the program is skipped, and a skip width in the radial direction is originally necessary to some extent. Can be close to the width. For example, an example of calculation in a case where a Blu-ray disc having a storage capacity of 25 GB (Giga Byte) is skipped by 50 μm in the radial direction is illustrated. First, a plurality of areas provided on the optical disc will be described with reference to FIG. As shown in FIG. 7, the optical disk 17 is divided into three regions, the region RA is in the range of radius 24 mm to less than 35 mm, the region RB is in the range of radius 35 mm to radius 45 mm, and the region RC is in the range of radius 45 mm to radius 58 mm. The area can be divided into three. From the calculation of the equation, the number of skip sectors in the area RA is 3C00h at the point of the radius 35 mm that is the outermost periphery of the area RA, so the number of skip sectors in the area RA can be set to 3C00h. Similarly, 4D20h is required as the number of skip sectors at a point with a radius of 45 mm, which is the outermost periphery of the region RB. Therefore, the number of skip sectors in the region RB can be set to 4D20h. Similarly, since the number of skip sectors is 6360h at the point of radius 58 mm, which is the outermost periphery of the region RC, the number of skip sectors in the region RC can be set to 6360h.

  When it is necessary to skip within each area, the CPU of the control unit 12 performs calculation based on the formula each time it skips by adopting the number of skip sectors calculated in advance as described above. There is no need, and to some extent, it can be close to the number of skip sectors originally required. In the second embodiment, the optical disk is divided into three areas. Naturally, the number of divisions of this area is not limited to three. The more the number of divisions is increased, the more skip sectors can be formed to the originally required width. Asymptotically close to the number.

It is a figure which shows the positional relationship of the track groove and bubble of an optical disk. It is another figure which shows the positional relationship of the track groove and bubble of an optical disk. It is a figure which shows typically the relationship between a physical address and a radius. It is a figure which shows the outline | summary of a structure of an optical disk apparatus. It is a figure which shows an example of the waveform of the tracking signal detected from a servo signal detection part and a physical address detection part. It is a figure which shows the procedure of recording typically. It is a figure explaining the several area | region provided in the optical disk. It is a figure which shows typically the procedure of recording as background art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Optical disk apparatus, 12 Control part, 13 Servo signal detection part / Physical address detection part, 14 Servo drive part, 15 Recording / reproduction | regeneration processing part, 16 Optical pick-up, 17 Optical disk, 18 Spindle motor, 19 Thread feed motor, Bubble 30, TE tracking signal

Claims (5)

Recording means for continuously recording data along track grooves provided on the optical disc;
An optical disc defect detecting means for detecting a defect of the optical disc;
An optical disc apparatus comprising: control means for controlling the recording means so as to continuously record the data while avoiding a predetermined range at a certain distance in the radial direction after the position where the defect is detected. The optical disc is
A recording area divided into sector units for performing recording with a constant linear density along the track groove,
The control means includes
Obtain the number of sectors included in the predetermined range at a certain distance in the radial direction from the position in the radial direction of the optical disc where the defect of the optical disc is detected,
2. The optical disc apparatus according to claim 1, wherein the recording of the data is continued continuously while avoiding the range of the determined number of sectors from the sector at the position where the defect is detected. The optical disc is
A recording area divided into sector units for performing recording with a constant linear density along the track groove,
The control means
Area determining means for determining which position in the radial direction of the optical disk where the defect of the optical disk is detected belongs to which of a plurality of areas classified in advance according to the size of the radius;
The recording of the data is continued, avoiding a predetermined number of sectors corresponding to the area determined by the area determination means from the sector at the position where the defect is detected. Optical disk device. 2. The optical disk device according to claim 1, wherein the defect of the optical disk is a bubble existing between a recording layer and a protective film surface of the optical disk. Irradiate a light spot along the track groove provided on the optical disc,
Detecting a defect of the optical disc by return light from the optical disc;
A method of recording an optical disc, wherein the recording of the data is continuously continued along the track groove while avoiding a predetermined range at a certain distance in the radial direction after the position where the defect is detected.

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