JP2018063744A - Inspection method of optical disk - Google Patents

Abstract

An inspection method capable of inspecting whether or not an optical disk is in a state where data can be normally recorded with high accuracy is provided. A method for inspecting a recording type optical disc 80 includes a condensing step (S11) for condensing laser light on a recording layer, and an acquisition step (S12) for acquiring a data signal corresponding to the laser light reflected by the recording layer. ). The inspection method determines whether or not there is an abnormality in the optical disc 80 by specifying a first period in which the signal level of the acquired data signal is lower than a predetermined value for each second period corresponding to the ECC block 82 (S13). A determination step (S14 to S16) to be performed, and an output step (S17) to output a determination result. [Selection] Figure 7

Description

  The present disclosure relates to an inspection method for inspecting whether an optical disc is in a state where data can be normally recorded or reproduced.

  Optical discs capable of recording information (data) are widespread and widely used. Patent Document 1 discloses a method for detecting defects in an optical disc that detects defects such as scratches or dirt attached to the surface of the optical disc.

Japanese Patent Laid-Open No. 10-40546

  The present disclosure provides an inspection method capable of inspecting whether an optical disc is in a state where data can be normally recorded or reproduced with high accuracy.

  The inspection method of the present disclosure is a method for inspecting a recordable optical disc, and the optical disc includes a recording layer including a plurality of recording units that are units in which error correction is performed when data is recorded. The method includes: a condensing step of condensing laser light on the recording layer; an acquisition step of acquiring an electric signal corresponding to the laser light reflected by the recording layer; and the acquired electric signal. Determining the presence or absence of abnormality of the optical disc by specifying the first period in which the signal level of the optical signal is lower than a predetermined value for each second period corresponding to the recording unit, and outputting the determination result Including.

  The inspection method of the present disclosure can inspect whether or not the optical disk is in a state where data can be normally recorded or reproduced with high accuracy.

FIG. 1 is an external perspective view of an information recording system according to an embodiment. FIG. 2 is an external perspective view of the magazine. FIG. 3 is an exploded perspective view of the magazine. FIG. 4 is a schematic cross-sectional view showing the structure of the recording layer of the optical disc. FIG. 5 is a plan view showing the structure of the recording layer of the optical disc. FIG. 6 is a block diagram showing a functional configuration of the information recording system according to the embodiment. FIG. 7 is a flowchart of an optical disk inspection method. FIG. 8 is a diagram for explaining a method of specifying the first period of the second control unit. FIG. 9 is a first schematic diagram illustrating a recording layer on which laser light is condensed. FIG. 10 is a second schematic diagram showing the recording layer on which the laser beam is condensed. FIG. 11 is a schematic diagram for explaining a method for estimating the presence or absence of scratches or deposits that are long in the radial direction.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  In addition, the inventors provide the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and these are intended to limit the subject matter described in the claims. is not. The accompanying drawings are schematic and are not necessarily shown strictly. In the accompanying drawings, substantially the same configuration is denoted by the same reference numeral, and redundant description may be omitted or simplified.

(Embodiment)
[Outline of information recording system]
First, an outline of the information recording system according to the embodiment will be described. FIG. 1 is an external perspective view of an information recording system according to an embodiment.

  As shown in FIG. 1, the information recording system 200 includes an information recording device 100, an information terminal 110, and a display device 120.

  The information recording apparatus 100 is a data archiver that stores data using a plurality of optical disks. The information terminal 110 and the display device 120 are user interfaces in the information recording system 200, and the user uses the information terminal 110 and the display device 120 to read information recorded on the information recording device 100 and to record the information on the information recording device 100. The information recording instruction to 100 can be performed.

  Specifically, the information recording apparatus 100 includes a magazine stocker 10, a plurality of magazines 20, a picker 30, a carrier 40, a plurality of disk drives 50, and a control device 60.

  The magazine 20 is a housing that houses a plurality of optical disks. FIG. 2 is an external perspective view of the magazine 20, and FIG. 3 is an exploded perspective view of the magazine 20.

  As shown in FIGS. 2 and 3, the magazine 20 includes a magazine tray 21 that accommodates a plurality of optical discs 80 stacked in the vertical direction, and a case 22 that accommodates the magazine tray 21. For example, 12 optical disks 80 are accommodated in one magazine tray 21.

  The optical disc 80 is a disc-shaped recording medium. In the embodiment, the optical disk 80 is a recordable (write-once) optical disk, and records, for example, about 100 GB of data per sheet. The write-once optical disc 80 is a recording medium for additionally recording information, and once recorded data cannot be rewritten.

  The picker 30 selects one magazine 20 from the plurality of magazines 20 accommodated in the magazine stocker 10 and pulls out the magazine tray 21 of the selected magazine 20. The picker 30 holds the magazine tray 21 that has been pulled out and conveys it to the vicinity of the plurality of disk drives 50. The picker 30 includes a separator 31 that separates a plurality of optical disks 80 stored in the magazine tray 21 so as not to contact each other.

  The carrier 40 receives the plurality of optical disks 80 separated by the separator 31 from the separator 31 in the separated state, and inserts them one by one into the insertion ports 51 of the plurality of disk drives 50.

  The disk drive 50 is a device that records information on the optical disk 80 and plays back the optical disk 80. The disk drive 50 is a slot-in type disk drive that loads the optical disk 80 without using a tray. The plurality of disk drives 50 are stacked in the vertical direction (height direction). The total number of the plurality of disk drives 50 provided in the information recording apparatus 100 is equal to the total number of optical disks 80 accommodated in the magazine 20, and is 12 in the embodiment.

  The control device 60 is a control device that controls the operation of each device such as the picker 30, the carrier 40, and the disk drive 50.

  The information recording apparatus 100 as described above inspects a plurality of magazines 20 before starting use. Specifically, the information recording apparatus 100 inspects the optical disk 80 for scratches or adhering material when the optical disk 80 in the magazine 20 is not recorded.

[Structure of optical disc]
Next, the structure of the recording layer of the optical disc 80 will be described. FIG. 4 is a schematic cross-sectional view showing the structure of the recording layer of the optical disc. FIG. 5 is a plan view showing the structure of the recording layer of the optical disc.

  As described above, the optical disk 80 is a recordable (write-once) optical disk. As shown in FIG. 4, the optical disc 80 has three recording layers on the upper surface and the lower surface, respectively. The optical disc 80 has three recording layers, Layer 0 (L 0 in FIG. 4), Layer 1 (L 1 in FIG. 4), and Layer 2 (L 2 in FIG. 4) on the upper surface side, and Layer 0, Layer 1 and Layer 2 on the lower surface side. 3 recording layers.

  Also, as shown in FIG. 5, in one recording layer, a groove (groove) is formed in a spiral shape from the vicinity of the center, and one of the groove and land (area between the groove and the groove) has a recording mark. The track 81 is formed. Note that both the groove and the land may be the track 81.

  The track 81 is divided into a plurality of ECC (Error Collecting Code) blocks 82. In other words, the plurality of ECC blocks 82 form a spiral track in the recording layer. The ECC block 82 is an example of a recording unit, and is a unit in which error correction is performed when data is recorded.

  The track 81 (groove) has a fine wobbling structure along the track 81, and the disk drive 50 can recognize the wobbling structure as address information in the optical disk 80. According to the wobbling structure, the disk drive 50 can specify the address stably even in the optical disk 80 before data is recorded.

[Functional configuration of information recording system]
Next, the functional configuration of the information recording system 200 will be described. FIG. 6 is a block diagram showing a functional configuration of the information recording system 200.

  As shown in FIG. 6, the information recording system 200 includes an information recording device 100, an information terminal 110, and a display device 120. The information terminal 110 is, for example, a personal computer, and the display device 120 is, for example, a liquid crystal display.

  The information recording apparatus 100 mainly includes a disk drive 50 and a control device 60. First, the detailed configuration of the disk drive 50 will be described. The disk drive 50 includes an optical head 52, a spindle motor 53, a servo control unit 54, an address specifying unit 55, a binarization processing unit 56, a laser drive unit 57, a first control unit 58, And a storage unit 59.

  The optical head 52 condenses the laser light on the recording layer of the optical disc 80 and receives the laser light reflected by the recording layer of the optical disc 80. The optical head 52 converts the received laser light into an electrical signal and outputs it. The optical head 52 outputs a wobble signal, a servo error signal, and a data signal as electrical signals. Specifically, the optical head 52 is an optical pickup device, and includes a laser light source that emits laser light, and a photodetector (photodiode) that converts the laser light into an electrical signal.

  The wobble signal is a signal corresponding to the wobbling structure of the optical disc 80 and is a signal indicating the address of the position where the laser beam is condensed (condensing position) in the track 81. The servo error signal is a signal for focusing the laser beam on the recording layer and causing the condensing position to follow the track 81. The data signal is a signal indicating data recorded on the track 81.

  The spindle motor 53 rotates the optical disc 80 based on the control of the servo control unit 54. The servo control unit 54 performs control to focus the laser beam on the recording layer and cause the light collection position to follow the track 81 based on the servo error signal output from the optical head 52. The servo control unit 54 controls the rotation speed of the spindle motor 53. The servo control unit 54 is controlled by the first control unit 58, for example.

  The address specifying unit 55 specifies the address of the condensing position of the laser beam in the recording layer based on the wobble signal. Specifically, the address specifying unit 55 includes an ADC (Analog Digital Converter) circuit. The ADC circuit performs HPF (High Pass Filter) processing that suppresses DC fluctuation on the wobble signal, LPF (Low Pass Filter) processing that removes high frequency noise unnecessary for wobble signal reproduction, and amplitude of the wobble signal. Analog signal processing such as AGC (Auto Gain Control) processing for suppressing fluctuation is performed.

  The address specifying unit 55 further includes a PLL (Phase Locked Loop) circuit and a demodulation circuit. The ADC circuit digitizes the wobble signal after the analog signal processing using the clock signal supplied from the PLL circuit. The PLL circuit generates and outputs a clock signal synchronized with the wobble signal from the digitized and BPF-processed wobble signal. The demodulation circuit demodulates the address information from the sampled wobble signal based on the clock signal output from the PLL circuit. As a result, the address of the condensing position of the laser in the recording layer is specified.

  The binarization processing unit 56 performs a process of binarizing the data signal output from the optical head 52. Specifically, the binarization processing unit 56 includes an ADC circuit. The ADC circuit performs analog signal processing such as HPF processing for suppressing DC fluctuation, LPF processing for removing high-frequency noise unnecessary for binarization, and AGC processing for suppressing amplitude fluctuation of the data signal. I do.

  The binarization processing unit 56 further includes a PLL circuit, an adaptive filter, and a demodulation circuit. The ADC circuit digitizes the data signal using the clock signal supplied from the data PLL circuit. The digitized data signal is filtered by an adaptive filter and then converted into binary data by a demodulation circuit. Although details are not shown, error correction processing or the like is performed on the binarized data.

  The laser drive unit 57 causes the optical head 52 to emit laser light based on the control of the first control unit 58. Specifically, the laser drive unit 57 is a drive circuit for a semiconductor laser. The laser driving unit 57 may be included in the optical head 52.

  The first control unit 58 controls each component included in the disk drive 50 and communicates with the control device 60. Specifically, the first control unit 58 is realized by a processor, a microcomputer, a dedicated circuit, or the like. The first control unit 58 may be realized by a combination of two or more of a processor, a microcomputer, and a dedicated circuit. Although details are not shown, a communication interface (communication circuit) is interposed between the first control unit 58 and the control device 60.

  The first storage unit 59 is a storage device in which a control program executed by the first control unit 58 is stored. Specifically, the first storage unit 59 is realized by a semiconductor memory or the like.

  Next, the control device 60 will be described. The control device 60 includes a second control unit 61 and a second storage unit 62.

  The second control unit 61 controls the operation of each device such as the picker 30, the carrier 40, and the disk drive 50 based on an instruction from the information terminal 110, for example. Specifically, the second control unit 61 is realized by a processor, a microcomputer, a dedicated circuit, or the like. The second control unit 61 may be realized by a combination of two or more of a processor, a microcomputer, and a dedicated circuit. Although details are not shown, a communication interface (communication circuit) is interposed between the second control unit 61 and the information terminal 110.

  Further, the second control unit 61 inspects the optical disc 80 for scratches or deposits before the information recording apparatus 100 is used, that is, when the optical disc 80 in the magazine 20 is not recorded. . Details of such inspection will be described later.

  The second storage unit 62 is a storage device that stores a control program executed by the second control unit 61. This control program includes a program for inspecting the optical disk 80 (magazine 20). Specifically, the second storage unit 62 is realized by a semiconductor memory or the like.

[Optical inspection method]
Next, an inspection method for the optical disk 80 in the magazine 20 performed by the control device 60 (second control unit 61) will be described. FIG. 7 is a flowchart of an inspection method for the optical disc 80. 7 shows an inspection method performed on one optical disk 80 after the second controller 61 controls the picker 30 and the carrier 40 to insert the optical disk 80 into the disk drive 50.

  First, the second control unit 61 condenses the laser beam on the recording layer of the optical disc 80 by controlling the laser driving unit 57 and the servo control unit 54 via the first control unit 58 (S11). At this time, the second control unit 61 controls the servo control unit 54 via the first control unit 58 to rotate the spindle motor 53, so that the beam spot of the laser beam condensed on the recording layer is changed to the optical disc 80. The track 81 of the recording layer is followed.

  Next, the second control unit 61 acquires a data signal corresponding to the laser light reflected by the recording layer (S12). In a state where data is recorded on the recording layer, the data signal is a signal whose signal level varies according to the recorded data, but this inspection method is performed on the optical disc 80 on which no data is recorded. . In a state where data is not recorded, the data signal usually has a substantially constant signal level. However, when there is a flaw or an adhering substance on the surface of the optical disc 80, the reflection level of the laser beam decreases, so the signal level is low. descend. That is, the period during which the signal level of the data signal is reduced can be regarded as a period in which there are scratches or deposits.

  Therefore, the second control unit 61 specifies, for each second period corresponding to the ECC block 82, a first period in which the signal level of the data signal is lower than a predetermined value in the data signal acquired in step S12 ( S13). FIG. 8 is a diagram for explaining a method of specifying the first period.

In FIG. 8, the data signal under inspection is shown. As described above, the beam spot of the laser beam condensed on the recording layer advances along the track 81 by the rotation of the optical disc. If there are scratches or deposits on the target portion of the surface of the optical disc 80, the signal level of the data signal decreases while the beam spot is hitting the portion of the track 81 that overlaps the target portion. In Figure 8, in the first period T _1, the signal level of the data signal is lower than a predetermined value.

As the length of the first period T ₁ is longer, a large scratch or deposit on the surface of the optical disk 80 is considered there. Therefore, the length of the first period T ₁ is is longer than a predetermined time period, such the optical disk 80 is abnormal (unusable) and determines inspection methods are conceivable. This is because such an optical disk 80 may not be able to normally record or reproduce data due to a flaw or a deposit.

However, the optical disc 80 determined to be unusable by such an inspection method may actually be usable. Specifically, as shown in FIG. 8, when the first period T ₁ extends over the two second periods T ₂₁ and T ₂₂ , that is, scratches or deposits are two ECC blocks 82. It is a case that exists across.

As described above, the ECC block 82 is a unit in which error correction is performed when data is reproduced. If an area free from scratches or deposits is secured in one ECC block 82, error correction is possible, and normally there is no problem in data reproduction. In the example of FIG. 8, in the first period T ₁ , the first period T ₁₁ belonging to the second period T ₂₁ corresponding to one ECC block 82 and the second period T ₂₂ corresponding to the other ECC block 82 are included. It includes a first time period _{T 12} that belongs. In such a case, if it is less than the length and respective lengths a predetermined length of the first period T ₁₂ in the first period T _11, normally does not occur a problem in the recording of data.

Therefore, in step S13, the second control unit 61 does not specify the first period regardless of the ECC block 82, but specifies the first period for each second period corresponding to the ECC block 82 in the data signal. . In the example of FIG. 8, the second control unit 61 identifies the first period T ₁₁ contained in the second period T _21, it identifies a first time period T ₁₂ contained in the second period T _22.

  Note that the start point and end point of the second period (the boundary between the two ECC blocks 82) of the data signal can be specified based on the address output from the address specifying unit 55. Whether or not the data signal falls below a predetermined value can be specified by, for example, a comparator circuit. The predetermined value is, for example, 50% of the maximum value of the signal level of the data signal, but is not particularly limited.

Then, the second control unit 61, each of the length and the length of the first period T ₁₂ in the first period T ₁₁ is equal to or a predetermined length or longer (S14). The length of the first period can be measured by, for example, a time counter. The predetermined length is, for example, a length corresponding to an information amount of 600 bytes. Since the length of the second period corresponds to the information amount of 64 KBytes, the predetermined length is about 1% of the length of the second period. The predetermined length is not particularly limited, but may be a length corresponding to a predetermined amount of information that allows error correction.

The second control section 61, when at least one of the length of the length and the first period T ₁₂ in the first period T ₁₁ is determined to be a predetermined length or longer (Yes in S14), there is an abnormality in the optical disk 80 (S15). That is, it is determined that there are large scratches or deposits on the optical disc 80 that cannot normally record or reproduce data.

On the other hand, the second control unit 61, when both the length of the length and the first period T ₁₂ in the first period T ₁₁ is determined to be less than a predetermined length (No in S14), the abnormality in the optical disk 80 is It is determined that there is not (S16). That is, it is determined that there are no large scratches or deposits on the optical disc 80 that cannot normally record or reproduce data.

  Finally, the second control unit 61 outputs a determination result (S17). The determination result is output to the information terminal 110, for example. As a result, for example, an image indicating the determination result (inspection result) is displayed on the display device 120.

  According to the above inspection method, it is possible to inspect with high accuracy whether or not the optical disc 80 is in a state where data can be normally recorded or reproduced.

[Modification 1]
As described above, the optical disc 80 has three recording layers on the upper surface and the lower surface, respectively. That is, the optical disc 80 has a structure in which a plurality of recording layers are stacked. Here, for example, when inspecting one surface of the upper surface and the lower surface of the optical disc 80, the laser light may be focused on one of the three recording layers. At this time, the laser beam may be focused on any of the three recording layers. 9 and 10 are schematic views showing the recording layer on which the laser beam is condensed.

  In FIG. 9, the laser beam is focused on Layer 0 which is the recording layer farthest from the optical head 52 among the plurality of recording layers. In FIG. 10, Layer 2 which is the recording layer closest to the optical head 52 among the plurality of recording layers. The laser beam is condensed on the surface.

  Here, the beam spot diameter r1 on the surface of the optical disc 80 when the laser beam is focused on Layer 0 is smaller than the beam spot diameter r2 on the surface of the optical disc 80 when the laser beam is focused on Layer 2. . As shown in FIGS. 9 and 10, the deposit 70 adheres to the surface of the optical disc 80, and therefore, the smaller the beam spot diameter on the surface, the more accurately the presence / absence of the deposit 70 can be inspected. That is, as shown in FIG. 10, the laser beam is focused on the recording layer closest to the optical head 52 among the plurality of recording layers included in the optical disc 80, so that the inspection accuracy can be improved.

[Modification 2]
It is desirable that the optical disk 80 is free from any scratches or deposits that may hinder data recording or reproduction. Therefore, in the inspection of the optical disc 80, the same number of second periods as the number of ECC blocks 82 included in one recording layer are specified, and all the specified second periods are included in the second period. Ideally, the condition that one period is less than a predetermined length is satisfied. In a double-sided recording type optical disc such as the optical disc 80, it is ideal that the above conditions are satisfied in each of the recording layer on the upper surface side and the recording layer on the lower surface side.

  However, when some of the specified second periods do not satisfy the condition, that is, the ECC block 82 (hereinafter referred to as an optical disk 80) that is estimated to be unusable for recording due to scratches or adhering matter. In this case, if the address of the defective ECC block is stored and recording in the defective ECC block is avoided, the optical disc 80 can be used. In other words, the defective ECC block is an ECC block corresponding to the second period including the first period of a predetermined length or more.

  Therefore, the second control unit 61 may determine whether or not there is an abnormality in the optical disc 80 based on the number of second periods including the first period of a predetermined length or more, that is, the number of defective ECC blocks. Specifically, the second control unit 61, when the number of second periods (the number of defective ECC blocks in the recording layer) including the first period of a predetermined length or more in the data signal is a predetermined number or more, It may be determined that the optical disk 80 is abnormal.

  The predetermined number may be determined according to the recording capacity, for example. The predetermined number is determined, for example, such that the total recording capacity of defective ECC blocks out of the maximum recording capacity of one optical disk 80 is less than 10%.

[Modification 3]
The second control unit 61 may determine that there is an abnormality in the optical disk 80 when it is estimated that there are long scratches or deposits in the radial direction of the optical disk 80. FIG. 11 is a schematic diagram for explaining a method for estimating the presence or absence of scratches or deposits that are long in the radial direction. The track 81 shown in FIG. 11 is actually a spiral shape, but is simplified for the sake of explanation.

  In FIG. 11, the ECC block group 83 includes a plurality of ECC blocks 82 included in a portion of the track 81 in the lth circle from the center (innermost circumference) of the optical disc 80. The ECC block group 84 includes a plurality of ECC blocks 82 included in the m-th portion from the center of the optical disk 80 in the track 81, and the ECC block group 85 is included in the n-th portion from the center of the track 81. It consists of a plurality of ECC blocks 82. Note that l, m, and n are different natural numbers.

  Here, when at least one defective ECC block is included in each of the ECC block group 83, the ECC block group 84, and the ECC block group 85, there is a deposit 71 (or a flaw) that is long in the radial direction. It is estimated that

  Therefore, if the second control unit 61 determines that at least one defective ECC block is included in each of the ECC block group 83, the ECC block group 84, and the ECC block group 85, the optical disk 80 is abnormal. You may judge.

  Specifically, the second control unit 61 includes, in the acquired data signal, a period corresponding to the l-th round portion of the track 81, a period corresponding to the m-th round portion of the track 81, and the track 81 If each of the periods corresponding to the n-th portion includes a second period including a first period of a predetermined length or more, it may be determined that the optical disk 80 is abnormal. Each of the period corresponding to the l-th portion of the track 81 in the data signal, the period corresponding to the m-th portion of the track 81, and the period corresponding to the n-th portion of the track 81 is as follows. It can be specified based on the address output from the address specifying unit 55.

  Thereby, the 2nd control part 61 can determine with the optical disk 80 estimated that there exists a crack or a deposit | attachment long in a radial direction having abnormality.

  Further, the 1st, mth and nth laps of the track 81 are set at equal intervals, for example. If l <m <n, m−1 is equal to nm. Each of ml and nm is an integer of 1 or more, for example. As described above, the second control unit 61 selects the first data having a predetermined length or more in each of N periods corresponding to N tracks of tracks that are not adjacent to each other and are selected at equal intervals from the data signal. When at least one second period including the period is included, it may be determined that there is an abnormality in the optical disc 80 (N is an integer of 2 or more).

  When the second control unit 61 determines that each of at least two ECC block groups (for example, the ECC block group 84 and the ECC block group 85) includes at least one defective ECC block, the optical disc What is necessary is just to determine with 80 having abnormality. That is, in the acquired data signal, the second control unit 61 has a period corresponding to the m-th portion of the track 81 from the center of the optical disc 80 and the n-th turn of the track 81 from the center of the optical disc 80. What is necessary is just to determine with the optical disk 80 having abnormality, when each of the period corresponding to a part contains the 2nd period containing the 1st period more than predetermined | prescribed length.

[Modification 4]
In the above inspection method, the determination result is output for each optical disc 80, but the determination result may be output for each magazine 20. That is, the presence / absence of abnormality (usability) may be determined for each magazine 20.

  Here, it is the upper surface of the first optical disk located at the top that is likely to cause scratches or deposits among the plurality of optical disks 80 accommodated in the magazine 20. This is because the upper surface of the first optical disk is easily in contact with the case 22. Similarly, the lower surface of the second optical disk positioned at the bottom of the plurality of optical disks 80 accommodated in the magazine 20 is likely to be scratched or adhered. This is because the lower surface of the second optical disk is likely to come into contact with the magazine tray 21.

  Therefore, when it is determined whether there is an abnormality for each magazine 20, not all the optical disks 80 in the magazine 20 are subject to inspection, but only the first optical disk and the second optical disk may be subject to inspection. . In more detail, only the recording layer on the upper surface side of the first optical disc and the recording layer on the lower surface side of the second optical disc may be subject to inspection.

  In this case, in the inspection, laser light is focused on the recording layer only for the recording layer on the upper surface side of the first optical disc and the recording layer on the lower surface side of the second optical disc. That is, only two recording layers are inspected for one magazine 20. Any of the methods described above may be used to determine whether there is an abnormality.

  When it is determined that at least one of the first optical disk and the second optical disk is abnormal, a determination result indicating that the magazine 20 is abnormal is output.

  As described above, by selectively inspecting only the recording layer on the upper surface side of the first optical disc and the recording layer on the lower surface side of the second optical disc, it is possible to efficiently determine whether the magazine 20 is abnormal. it can.

[Effects]
As described above, the above embodiment relates to a method for inspecting the recordable optical disk 80. The optical disc 80 has a recording layer including a plurality of ECC blocks 82, which are units in which error correction is performed when data is recorded. The ECC block 82 is an example of a recording unit. The inspection method includes a condensing step (S11) for condensing the laser beam on the recording layer, and an acquisition step (S12) for acquiring a data signal corresponding to the laser beam reflected by the recording layer. In the inspection method, the first period in which the signal level of the data signal is lower than a predetermined value is specified for each second period corresponding to the ECC block 82 in the acquired data signal (S13). A determination step (S14 to S16) for determining whether there is an abnormality and an output step (S17) for outputting a determination result are included. The data signal is an example of an electrical signal.

  According to such an inspection method, since the presence or absence of a flaw or a deposit that becomes an obstacle is determined for each ECC block 82, it is inspected with high accuracy whether or not the optical disc 80 is in a state in which data can be normally recorded. Can do.

  In the determination step, the optical disk 80 may be determined to be abnormal when the length of the first period included in the second period is equal to or greater than a predetermined length in the acquired data signal.

  Thereby, the inspection method can inspect the optical disc 80 in consideration of whether the ECC block 82 can perform error correction when data is recorded, for example.

  Further, as in Modification 2, in the determination step, whether or not there is an abnormality in the optical disk is determined based on the number of second periods including the first period of a predetermined length or more in the acquired data signal. Good.

  Thereby, the said inspection method can test | inspect the optical disk 80 in consideration of a required recording capacity, for example.

  Further, as in the third modification, the plurality of ECC blocks 82 constitute a spiral track 81 in the recording layer, and in the determination step, m (from the center of the optical disc 80 in the track 81 in the acquired data signal). m is a natural number) a period corresponding to a portion of the circumference, and a period corresponding to a portion of the track 81 corresponding to the nth (n is a natural number different from m) circumference from the center of the optical disc 80, respectively. When the second period including the first period is included, it may be determined that the optical disk 80 is abnormal.

  Thereby, the inspection method can determine that the optical disk 80, which is estimated to have a long scratch or deposit in the radial direction, is abnormal.

  Further, as in Modification 1, the optical disc 80 has a structure in which a plurality of recording layers are stacked, and in the condensing step, the recording layer closest to the optical head 52 that emits laser light among the plurality of recording layers. The laser beam may be condensed.

  Thereby, the beam spot diameter on the surface of the optical disk 80 is reduced. For this reason, the said inspection method can test | inspect the presence or absence of a deposit with high precision.

  Further, as in Modification 4, the inspection method is a plurality of optical disks 80 housed in the magazine 20 in a stacked state in the vertical direction, each of which has a recording layer on both the upper surface and the lower surface. Of these, only the first optical disk positioned at the top and the second optical disk positioned at the bottom may be performed. In the condensing step, the laser beam may be focused on the recording layer only for the recording layer on the upper surface side of the first optical disc and the recording layer on the lower surface side of the second optical disc. In the output step, if it is determined in the determination step that at least one of the first optical disk and the second optical disk is abnormal, a determination result indicating that the magazine is abnormal may be output.

  As a result, only the recording layer of the optical disc 80 to which scratches or deposits 70 easily adhere is selectively inspected. Therefore, the inspection method can efficiently determine whether the magazine 20 is abnormal.

  Further, the inspection method may be performed on the optical disc 80 on which no data is recorded.

  As a result, the inspection method can determine the presence or absence of scratches or deposits on the optical disc 80 on which no data has been recorded.

  As described above, the ECC block 82 is an example of a recording unit. That is, the recording unit may be an ECC block.

  As a result, the inspection method can inspect the presence or absence of scratches or deposits that become obstacles for each ECC block 82.

(Other embodiments)
As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated in the said embodiment and it can also be set as a new embodiment.

  Thus, hereinafter, other embodiments will be described together.

  In the above embodiment, the inspection method is executed by the second control unit provided in the control device, but may be executed by the first control unit provided in the disk drive. Each process included in the inspection method may be shared by each component included in the information recording apparatus.

  In the above embodiment, the components such as the first control unit and the second control unit may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Good. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

  In addition, the inspection methods of the above-described embodiments can be applied to various recording type optical discs. For example, the present invention can be applied to recordable discs such as AD (Archival Disc (registered trademark)), BD (Blu-ray Disc (registered trademark)), DVD, and CD. Further, the disk to be inspected may be a double-sided recording type or a single-sided recording type.

  Further, the order of the plurality of processes in the inspection method described in the above embodiment is an example. The order of the plurality of processes may be changed, and some of the plurality of processes may be executed in parallel.

  The comprehensive or specific aspect of the present disclosure is not limited to the inspection method, and may be realized as a system or an apparatus. In addition, a comprehensive or specific aspect of the present disclosure may be realized by a recording medium such as an integrated circuit, a computer program, or a computer-readable CD-ROM.

  For example, the present disclosure may be realized as the disk drive, the information recording apparatus, or the information recording system described in the above embodiments. Further, the present disclosure may be realized as a program for causing a computer to execute the inspection method, or may be realized as a non-temporary recording medium on which the program is recorded.

  As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The present disclosure is useful as a method for inspecting a recordable optical disk.

DESCRIPTION OF SYMBOLS 10 Magazine stocker 20 Magazine 21 Magazine tray 22 Case 30 Picker 31 Separator 40 Carrier 50 Disk drive 51 Insertion port 52 Optical head 53 Spindle motor 54 Servo control part 55 Address specification part 56 Binarization processing part 57 Laser drive part 58 First control Unit 59 First storage unit 60 Control device 61 Second control unit 62 Second storage unit 70 Deposited matter 71 Deposited matter 80 Optical disc 81 Track 82 ECC block 83, 84, 85 ECC block group 100 Information recording device 110 Information terminal 120 Display device 200 Information recording system

Claims (8)

A method for inspecting a recordable optical disc,
The optical disc has a recording layer including a plurality of recording units, which are units in which error correction is performed when data is recorded,
The inspection method is:
A condensing step of condensing laser light on the recording layer;
An acquisition step of acquiring an electrical signal corresponding to the laser beam reflected by the recording layer;
In the obtained electric signal, the first optical period in which the signal level of the electric signal is lower than a predetermined value is specified for each second period corresponding to the recording unit, thereby determining whether or not the optical disk is abnormal. A determination step;
An optical disk inspection method comprising: an output step for outputting a determination result. The determination step determines that the optical disc is abnormal when the length of the first period included in the second period is equal to or longer than a predetermined length in the acquired electrical signal. Inspection method of the optical disk as described in 2. 2. The determination step according to claim 1, wherein the presence or absence of an abnormality of the optical disc is determined based on the number of the second periods including the first period of a predetermined length or more in the acquired electrical signal. Optical disk inspection method. The plurality of recording units constitute a spiral track in the recording layer,
In the determination step, in the obtained electrical signal, a period corresponding to a m-th (m is a natural number) round portion of the track from the center of the optical disc, and n ( n is a natural number different from m) When each of the periods corresponding to the circumferential portion includes the second period including the first period having a predetermined length or more, it is determined that the optical disk is abnormal. The optical disk inspection method according to claim 1. The optical disc has a structure in which a plurality of recording layers are laminated,
5. The optical disk inspection method according to claim 1, wherein in the condensing step, the laser light is condensed on a recording layer closest to an optical head that emits the laser light among a plurality of recording layers. . The inspection method includes a plurality of optical disks housed in a magazine in a vertically stacked state, and each of the plurality of optical disks having recording layers on both the upper surface and the lower surface is positioned at the top. Performed only for the optical disc and the second optical disc located at the bottom,
In the condensing step, focusing only on the recording layer on the upper surface side of the first optical disc and the recording layer on the lower surface side of the second optical disc, the laser beam is condensed on the recording layer,
2. The output step outputs the determination result indicating that the magazine is abnormal when it is determined in the determination step that at least one of the first optical disc and the second optical disc is abnormal. The inspection method of the optical disk of any one of -5. The optical disc inspection method according to claim 1, wherein the inspection method is performed on the optical disc on which data is not recorded. The optical disc inspection method according to claim 1, wherein the recording unit is an ECC (Error Collecting Code) block.

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