KR20080040081A - Recording medium, method and apparatus for recording/reproducing information on/from the recording medium - Google Patents

Abstract

A recording medium, a method and an apparatus for recording/reproducing information on/from the recording medium are provided to protect data from defects by examining set areas and applying the examination result to the management area. Certification target areas(1a,1b,1c) are set in a recording medium having at least one recording layer. The set areas are examined. The examination result is applied to a management area. When setting the certification target areas, the initial position information of the certification target area, and the position information of the last area are set. The initial position information and the final position information are recorded in the disk management area.

Description

Recording medium, method and device for recording and reproducing recording medium {Recording medium, Method and Apparatus for recording / reproducing information on / from the recording medium}

1 illustrates an embodiment of a recording medium structure and a block verification method according to the present invention.

Figure 2 illustrates one embodiment of a disk management structure in accordance with the present invention.

Figure 3 shows one embodiment of a disc definition structure in a single-layer recording medium according to the present invention.

4 illustrates an embodiment of a block verification method in a multilayer recording medium according to the present invention.

Figure 5 illustrates one embodiment of a disc definition structure in a multilayer recording medium according to the present invention.

6 illustrates an embodiment of a defect list according to the present invention.

Figure 7 illustrates one embodiment of a disk definition structure according to the present invention.

8 shows a first embodiment of Disc Certification Flags according to the present invention.

9 shows a second embodiment of Disc Certification Flags according to the present invention.

10 shows an embodiment of a recording medium recording and reproducing apparatus according to the present invention.

Fig. 11 shows a first embodiment of a recording medium recording / reproducing method according to the present invention.

12 shows a second embodiment of a recording medium recording / reproducing method according to the present invention.

* Explanation of symbols for main parts of the drawings

20: Recording and playback section 11: Pick-up section

12: control unit 13: signal processing unit

14: Servo 15: Memory

16: Microcomputer 17: AV decoder

18: AV encoder

The present invention relates to a recording medium, a recording medium recording and reproducing method and apparatus, and more particularly, to a method and apparatus for efficiently recording and reproducing data on a recording medium.

As a recording medium, a disc capable of recording a large amount of data is widely used. Recently, new high-density recording media (for example, Blu-ray Discs (BDs)) capable of recording and storing high-quality video data and high-quality audio data for a long time have been developed.

Blu-ray Disc (BD), a next-generation recording media technology, is a next-generation optical recording solution that can record data that significantly exceeds existing DVDs. Recently, the world's standard technical specifications with other digital devices have been established.

On the other hand, a preferred management method for a case where a defect occurs in a recording medium having a plurality of recording layers in a recording method using a next-generation high-density recording medium such as a Blu-ray disc (BD) is not presented, so a full-fledged Blu-ray disc ( There are many limitations in developing a BD-based recording and reproducing apparatus.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a recording medium, a recording medium recording and reproducing method and apparatus for protecting data from defects.

In order to achieve the above object, the present invention comprises the steps of designating a region to be verified on a recording medium having one or more recording layers; Examining the designated area; And reflecting the inspection result in a management area.

According to another embodiment of the present invention, the present invention provides a method comprising: specifying an area to be verified on a recording medium having one or more recording layers; Examining the designated area against a background; And reflecting the inspection result in a defect management area.

According to still another embodiment of the present invention, there is provided a recording medium having at least one recording layer and having a management area, the method comprising: specifying an area to be verified; And recording the position information of the designated area in the management area.

According to another embodiment of the present invention, the present invention provides a recording medium having at least one recording layer, wherein the recording medium has a management area, and records the location information of the area to be verified in the management area. A recording medium is provided which records information representing a verification result in the management area.

According to still another aspect of the present invention, there is provided an apparatus comprising: a pickup unit for reading a signal from or recording a signal to a recording medium; And a control unit for controlling the pickup unit to read a signal in the verification area when the verification area is designated, wherein the control unit uses the read signal to determine a defect and update the defect information. do.

Other objects, features and advantages of the present invention will become apparent from the embodiments with reference to the accompanying drawings.

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

In addition, the terminology used in the present invention was selected as a general term that is widely used at present, but in certain cases, the term is arbitrarily selected by the applicant, and in this case, since the meaning is described in detail in the corresponding part of the present invention, a simple term It is to be understood that the present invention is to be understood as meanings of terms other than names.

In this regard, in the present invention, "recording medium" means any medium on which data is recorded or is recordable, and encompasses all mediums regardless of a recording method such as a disc, a magnetic tape, and the like. Hereinafter, the present invention will be described by using a disc (disc), in particular, a "Blu-ray Disc (BD)" as a recording medium for convenience of explanation. will be.

In addition, in the present invention, "management area" means an area for recording management information of a recording medium. In the present invention, the management area will be described based on a disc management area (DMA), but the present invention can also be applied to a temporary disc management area (TMDA). In the disc management area, a disc management structure (DMS) is recorded. The disc management structure (DMS) includes a defect list (DFL) and a disc definition structure (DDS). The defect list (DFL) is a list containing the type and location of the defect, and the disc definition structure (DDS) includes the disc management information including the defect management information. The DMA may be provided in the inner region and the outer region, respectively.

In addition, in this invention, a "defect type" means the type which a defect represents. For example, in BD-RE, a defect type is a re-allocatable defect (RAD) type to which a reallocation address for a defect cluster is assigned, and an NRD to which a reallocation address for a defect cluster is not assigned. (non-re-allocatable defect) type, and possibly bad area (PBA) type, which is composed of clusters that are likely to be defective. The RAD type records data in the spare location and / or the alternate location, and the information on the defect cluster records the data in the original location and the first RAD type that records the defect list. The second RAD type is possible in which only the position of the defective cluster is assigned to the spare area. In BD-R, the defect type is a single cluster defect, which is assigned a reallocation address and a re-allocated defect (RAD) in which the original data is recorded at the spare location. Type, single cluster defects that represent defects, and are non-re-allocated defect (NRD) types that do not have reallocation addresses assigned, as contiguous multiple cluster defects. A contiguous re-allocated defect (CRD) type is possible where a contiguous range of reallocation addresses is assigned and the original data is recorded at the spare location.

Also, in the present invention, "certification" refers to checking the reliability of each cluster. There are the following types of certification methods. First, there is full certification. This method is to check the reliability of all clusters in the recording medium. Next is the Quick Certification. This verification method checks only the defective clusters registered in the defect list. Another method is block certification. This method is a method of specifying and checking the area to be verified by the user.

In particular, Block Certificaion verifies only the area designated by the user, which reduces the time required for verifying the unnecessary area, which is an effective method for defect management and recording and reproducing. On the contrary, in the case of a high-capacity multi-layer recording medium, full certification is inefficient because it requires a lot of time, and quick certification may also be inefficient because verification of unnecessary areas is performed by the user.

1 illustrates an embodiment of a structure of a recording medium according to the present invention and an embodiment of block certification. For convenience of explanation, the recording medium will be described using a rewritable Blu-ray disc as an example, but the present invention is not limited thereto, and it is obvious that the present invention can be applied to other recording media. In addition, although the description will be made based on a single layer having a single recording layer of the recording medium, the present invention is also applicable to a recording medium having a plurality of recording layers.

The disk to which the present invention is applicable is composed of an inner zone, a data zone and an outer zone from the disk inner circumference. The data area includes a user data area for recording user data and a spare area for disc defect management. The spare area includes an inner spare area (ISA) located at the inner circumference of the data area and an outer spare area (OSA) located at the outer circumference of the data area.

The DMA serving as the disk management area can be allocated to the inner area and the outer area. For example, as shown in FIG. 1, DMA1 and DMA2 may be provided in the inner region, and DMA3 and DMA4 may be provided in the outer region. The disc management structure (DMS) is recorded in the management area.

The hatched areas 1a, 1b and 1c in FIG. 1 indicate defective areas. Here, the dashed box 2 represents the area to be verified by the user. If the user wants to verify only the inner area of the dotted box, the user can specify the location information of the area to be verified. The location information can be specified in various ways. In FIG. 1, a physical sector number (PSN) is designated as one method of specifying location information. That is, the user designates the first PSN (P1) and the last PSN (P2) of the area to be verified. Alternatively, the user may specify the length of the first PSN and block of the region to be verified. Here, the first PSN refers to the first physical sector of the first cluster of the region to be verified by the user, and the last PSN refers to the first physical sector of the last cluster of the region to be verified by the user. This verifies all clusters between the first PSN and the last PSN, including those with PSNs.

2 shows an embodiment of a disc management structure. The disk definition structure (DDS) is repeatedly recorded in the first four clusters of each disk management area. Then, the defect list DFL is recorded in the four clusters. If there are defects in the four clusters in which the defect list (DFL) is recorded, the defect list is moved to the next four clusters. That is, as shown in FIG. 2, if the next four clusters (clusters 5 to 8) are defective, the next four clusters (clusters 9 to 12) are moved.

3 shows one embodiment of a disk definition structure (DDS) when a user designates an area to verify. The disc definition structure (DDS) is characterized by defining the format and state of the recording medium, including the recording medium management information including the defect management information. The disk definition structure stores information about the area to be verified by the user. In the embodiment as shown in FIG. 3, information about a first PSN and a last PSN of a region to be verified by a user is included. In the embodiment of Fig. 3, this location information is allocated to the disk definition structure (DDS) with a size of 4 bytes. In this case, it is obvious that the size of the allocated area may vary depending on the type of the recording medium.

4 shows an embodiment of the present invention in a multi-layer recording medium. In the case of a multi-layer recording medium, there is a high probability of finding a defect only in a specific area. That is, in a multilayer recording medium, when a defect occurs in any one layer, due to the damage of the optical properties of the portion, the regions at the same position in the other layer are likely to be determined as defective regions. In this case, in the present invention, the verification is performed by designating an area that is on another floor but is located at the same position vertically. 4A, 4B, 4C, and 4D of FIG. 4 are defective regions that are on different layers but exist at the same vertical position. If the user wants to perform verification of these areas, the user can specify the first and last PSN of each of these areas. In other words, in the embodiment of FIG. 4, P1P2, P3P4, P5P6, and P7P8 may be designated. In addition, when there is another region to be verified (4e), the first PSN and the last PSN of the region to be verified may be further specified as shown in P9P10 of FIG. 4.

FIG. 5 shows an embodiment of a disc definition structure (DDS) when a plurality of areas to be verified are designated in a multi-layer recording medium. According to the verification method according to the present invention, it is possible to designate several verification areas. In addition, when a plurality of verification areas are designated, the start position information and the end position information of each area may be shown in the disk definition structure (DDS) as shown in FIG. 5. In the embodiment shown in Fig. 5, the start position information and the end position information are made possible by designating the physical position. That is, the information about the region to be verified is indicated by designating the first PSN and the last PSN of the region to be verified. At this time, the first PSN and the last PSN are represented by 4 bytes, which are recorded in the disk definition structure (DDS).

6 illustrates an embodiment of a defect list according to the present invention.

Referring to FIG. 6, a defect list is defect management information recorded in a management area, a defect list entry indicating a 'Status 1' field indicating first status information of an entry, and a PSN of a first physical sector of a cluster to be replaced or indicated. 'Defective Cluster first PSN' field, 'Status 2' field indicating the second status information of the entry, 'Replacement Cluster first PSN' indicating the PSN of the first physical sector of the cluster indicating the length of the replaced cluster or PBA. Contains a field.

For example, referring to the defect cluster type according to the 'Status 1' field, when the 'Status 1' field is '0000' (Status 1 = 0000), it indicates the first RAD type, and the 'Status 1' field is '1000'. '(Status 1 = 1000) indicates the second RAD type, and when the' Status 1 'field is' 0001' (Status 1 = 0001) indicates the NRD type, and the 'Status 1' field is' 0010 ' (Status 1 = 0010) indicates the SPR type, when the 'Status 1' field is '0100' (Status 1 = 0100) indicates the PBA type, and when the 'Status 1' field is '0111' (Status 1 = 0111) may indicate an Unusable type.

In addition, the meaning indicated by the 'Status 2' field will be described. When the 'Status 2' field is '0000' (Status 2 = 0000), this indicates a setting when the following setting is not valid. If the 'Status 2' field is '1000' (Status 2 = 0000), then a replacement address is assigned and indicates a RAD with the content recorded at the replacement address, which is simply It is meaningful when combined. If the 'Status 2' field is '0100' (Status 2 = 0100), then if the entry indicates a PBA, it indicates that the clusters do not contain any relevant user data, which is simply Status 1 = 0100, Status It is meaningful when combined with 1 = 0010.

After verification according to the present invention, the PBA (Status 1 = 0100) and SPR (Status 1 = 0010, Status 2 = 0100) in the defect list DFL are lost. PBA clusters that were originally in the defect list (DFL) are removed from the defect list (DFL) if the verification proves that there are no defects. If it is determined that the PBA cluster is defective, it is registered with appropriate status information in the defect list. In the case of SPR (Status 1 = 0010, Status 2 = 0100) in the defect list DFL, if it is determined that there is no defect after verification according to the present invention, the Status 2 field is converted to 0000. If the SPR (Status 1 = 0010, Status 2 = 0100) is found to be defective, the cluster will change to Unusable type. As mentioned in the previous paragraph, the Status 1 field of an Unsuable cluster is 0111.

7 shows another embodiment of a disc definition structure (DDS) according to the present invention. Disc Certification Flags indicate information on a recording medium verification status. Embodiments of Disc Certification Flags are shown in FIGS. 8 and 9. The Last Verified Address Pointer indicates information on the recording medium at the point where the recording medium was last verified. This Last Verified Address Pointer is represented by 4 bytes. The Last Verified Address Pointer is represented as the first PSN of the last verified cluster during verification. Also, the Last Verified Address Pointer is valid only when verification is in progress. This embodiment is suitable when the recording medium verification of the present invention proceeds in the background. Background verification is performed when the application is not running, but when the application starts running, it stops the verification and runs the application, and when the application terminates, the verification is performed again. Means that. After the application is terminated, information at the point where verification is stopped is required to restart verification. The Last Verified Address Pointer indicates where the verification is completed. Disc Certification Flags also indicate the type and status of the verification being performed on the recording medium. Specific embodiments are shown in FIGS. 8 and 9.

8 shows a first embodiment of disc certification flags according to the present invention.

Here, b ₀ to b ₇ represent bits allocated to the disc certification flags. Where b ₇ b ₆ represents a Certification Status. The verification status indicates whether the recording medium is being verified or whether verification has been completed and the type of verification that has been completed. If the recording medium is not verified, b ₇ b ₆ = 00, and if the recording medium is being verified, b ₇ b ₆ = 01. In addition, if block certification or quick certification is applied to the recording medium and completed, b ₇ b ₆ = 10. In addition, if full certification is completed, b ₇ b ₆ = 11 is displayed.

b ₅ b ₄ indicates whether verification is in progress on the recording medium and how verification is in progress. b ₅ b ₄ = 00 indicates that no verification method is in progress. b ₅ b ₄ = 01 indicates that block certification is in progress. b ₅ b ₄ = 10 indicates that Quick Certification is in progress. b ₅ b ₄ = 11 indicates that Full Certification is in progress.

b ₃ represents a scanning state. In this case, scanning means quickly verifying a recording medium. Through this process, the status of PBA (Status 1 = 0100) is registered in the defect list DFL. b ₃ = 0 indicates that the recording medium was not scanned, and b ₃ = 1 indicates that the recording medium was scanned. Or it can also be shown in reverse. b ₂ b ₁ b ₀ is an unused bit and can be set to b ₂ b ₁ b ₀ = 000.

9 is a second embodiment of Disc Certification Flags according to the present invention. The difference from the first embodiment is that three bits are assigned to the verification status to indicate the status. Information on the state shown in FIG. 9 is as follows. As in FIG. 9, b ₀ to b ₇ represent bits allocated to Disc Certification Flags.

In the second embodiment, the bit indicating the certification status is b ₇ b ₆ b ₅ . b ₇ b ₆ b ₅ = 000 indicates that the recording medium has not been verified. b ₇ b ₆ b ₅ = 001 indicates that the record carrier has been partially verified. b ₇ b ₆ b ₅ = 010 indicates that block certification has been applied to the recording medium and has been completed. b ₇ b ₆ b ₅ = 011 indicates that Quick Certification has been applied to the recording medium and completed. b ₇ b ₆ b ₅ = 111 indicates that full certification has been applied to the recording medium and completed.

Here b ₄ b ₃ indicates whether verification is in progress on the recording medium and the verification method currently in progress. b ₄ b ₃ = 00 indicates that no verification method is in progress. b ₄ b ₃ = 01 indicates that block certification is in progress. b ₄ b ₃ = 10 indicates that Quick Certification is in progress. b ₄ b ₃ = 11 indicates full certification is in progress.

b ₂ represents a scanning status, and a status of b ₂ = 0 or b ₂ = 1 is the same as a status of b ₃ = 0 or b ₃ = 1 of FIG. 8. b ₁ b ₀ is an unused bit and can be set to b ₁ b ₀ = 00.

10 shows an embodiment of a recording medium recording and reproducing apparatus according to the present invention. The recording medium recording and reproducing apparatus of the present invention includes a recording and reproducing section 20 for recording data on a disk or reproducing the recorded data and a controller 12 for controlling the recording and reproducing data.

The recording / reproducing section 20 receives the signals read out from the pickup section 11 and the pickup section 11 for directly recording data on the disk or reading the data recorded on the disk, and restores them to a desired signal value. The signal processor 13 modulates and transmits a signal to be recorded into a signal recorded on the disk, and controls the pickup unit 11 to accurately read a signal from the disk or to accurately record a signal on the disk. And a servo unit 14, a memory 15 for temporarily storing management information and data including defect management information, and a microcomputer 16 for controlling the components. In this regard, a recording / reproducing apparatus composed only of the recording material generating section 20 is also referred to as a “drive”, which can be utilized as a computer peripheral device.

Further, in the present invention, when the pickup unit 11 verifies the recording medium, the pickup unit 11 reads out a signal of a designated area under the control of the microcomputer.

In addition, in the present invention, when verifying the recording medium, the microcomputer 16 controls the pickup unit 11 to read a signal of a designated area. In addition, the microcomputer 16 may control the verification of the area of the section selected for verification of the recording medium, and record the verification result in the management area.

The controller 12 is responsible for the control of the entire component, and in particular, in connection with the present invention, a user command or the like is received through an interface with a user, and a recording / playback command for recording or reproducing data on a disc is provided. The recording and reproducing section 20 is transmitted. In addition, when the user designates an area to be verified, the controller 12 receives the command and transmits the command to the recording and reproducing unit 20.

The AV decoder 17 decodes the signal read out from the disc under the control of the controller 12, restores it to desired information, and provides the same to the user.

The AV encoder 18 converts an input signal into a signal of a specific format, for example, an MPEG2 transport stream, and provides it to the signal processor 13 under the control of the controller 12 to perform a function of recording a signal on a disc. Done.

In the present invention, the functions of the controller 12 and the microcomputer 16 may operate by dividing into a first control unit and a second control unit, respectively. Alternatively, the functions of the controller 12 and the microcomputer 16 may be combined to operate as a single control unit.

11 is a flowchart showing a first embodiment of a verification method according to the present invention.

First, the user sets an area to be verified (S10). The setting of the area to be verified by the user is possible by inputting location information of the area to be verified by the user. For example, the user may input the first PSN and the last PSN of the area to be verified. In addition, in designating an area to be verified, one or more areas may be designated. Here, the first PSN refers to the first physical sector of the first cluster of the region to be verified by the user, and the last PSN refers to the first physical sector of the last cluster of the region to be verified by the user. This verifies all clusters between the first PSN and the last PSN, including those with PSNs.

In this case, a command may be used to designate an area to be verified by the user. One example of defining the command is Multimedia Command 5 (MMC5). In the command system of the same type as MMC5, the contents of the certification or format type of the recording medium can be defined. Full certification, Quick Certificaiton, and Block Certification of the present invention may be defined as sub-type fields.

After setting the area to be verified by the user, the stability is checked in the area (S20).

After checking the stability of the designated area, the result is recorded in the management area (S30). In other words, the defect is registered again in the defect list (DFL) by using the inspection result, and if it was previously found to be defective, the verification result is deleted from the defect list (DFL). . In addition, Disc Certification Flags are updated. The PBAs (Status 1 = 0100) and SPR (Status 1 = 0010, Status 2 = 0100) in the defect list disappear and a new defect list DFL is generated.

12 is a flowchart illustrating a second embodiment of a verification method according to the present invention. According to the second embodiment, the verification method according to the present invention can be performed in the background. In this case, the background verification is performed when no application program is running on the drive that records / reproduces the recording medium. When the application starts, the verification that is running is stopped and the application is stopped. When the program ends, it means how to resume verification. 12 illustrates how verification is performed in the background.

First, a user designates an area to be verified (S110). Specifying an area to be verified by the user is the same as that of the first embodiment of the recording / playback method shown in FIG. After the user designates the area to be verified, it is determined whether to proceed with the verification in the background (S120). If the verification is not performed in the background, the method is performed as shown in FIG. 11. After the decision to perform the verification in the background (background) is started the stability check (examination) within the specified area (S130). It is checked whether another application is running while checking stability in the designated area (S140). If another application program is not executed in the step of checking the stability of the designated area, the inspection is completed in the designated area (S180). If another application is running during an in-domain stability check, the check stops. When the inspection is interrupted, the disc certification flags are updated (S150). In addition, the Last Verified Address Pointer indicates to which extent the examination has proceeded (S160). That is, the Last Verified Address Pointer indicates the first physical sector of the last cluster in which the termination is completed. After execution of the application (S170), the inspection is automatically restarted using the Disc Certification Flags and Last Verified Address Pointer (S130).

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

The effects of the recording medium, the recording medium recording and reproducing method and apparatus according to the present invention described above are as follows. By verifying only the area selected by the user, verification time can be effectively reduced in high-capacity and multi-layered recording media, enabling effective defect management and recording and reproducing of recording media.

In addition, according to the present invention, in a multilayer recording medium, when a defective area is physically located at the same position across all of the recording layers, the defect area can be verified effectively.

Claims (23)

Designating an area to be verified on a recording medium having at least one recording layer; Inspecting the designated area; And reflecting the inspection result to a management area. The method of claim 1, The step of designating a region to be verified on the recording medium includes specifying first position information and last region position information of the region to be verified. The method of claim 2, The step of designating the first position information and the last position information of the region to be verified includes recording the first position information and the last position information in a disc management area. The method of claim 3, wherein Recording the first position information and the last position information of the inspection area in the disc management area, wherein each position information is allocated by 4 bytes in recording each position information. The method of claim 1, And the checking of the designated area comprises checking the reliability of the designated area. The method of claim 5, And checking the reliability of the designated area comprises inspecting all parts within the designated area. The method of claim 1, And reflecting the inspection result in a management area, indicating the inspection result in a defect list. The method of claim 1, And examining the designated area can proceed in the background. The method of claim 8, And the step of inspecting the designated area in the background is performed when the application program is not executed. The method of claim 8, In the background checking of the designated area, when the application is executed, the inspection is stopped and the application is executed. And re-inspecting where the last inspection was executed when the application is terminated. The method of claim 10, And specifying the last verified address point as the last verified address point. The method of claim 11, And wherein the last verified address pointer is expressed as the first Physical Sector Number (PSN) of the last verified cluster during verification. In a recording medium having at least one recording layer and having a management area, Designating an area to be verified; And recording position information of the designated area in a management area. The method of claim 13, The recording of the position information of the verification area in the management area, A recording medium recording and reproducing method, characterized by recording start position information and end position information of a verification area in a management area. The method of claim 14, And recording the start position information and the end position information in the management area by 4 bytes, respectively. The method of claim 13, When the verification is interrupted and restarted, And a last verified address pointer (Last Verified Address Pointer), which is the last address of the verified area, in the management area. In a recording medium having at least one recording layer, The recording medium has a management area, Record location information of the area to be verified in the management area; And recording information representing the verification status in the management area. The method of claim 17, To record the location information of the area to be verified in the management area, A recording medium, characterized in that for recording the start position and end position of the area to be verified. The method of claim 18, And recording the start position and the end position of the region to be verified in the management region by 4 bytes. The method of claim 17, When the verification is interrupted and restarted, And a last verified address pointer (Last Verified Address Pointer), which is a last address of the verified area, further included in a management area. A pickup unit for reading out a signal from the recording medium or recording the signal to the recording medium; If the verification area is specified, including a control unit for controlling the pickup to read a signal in the verification area, And the control unit uses the read signal to determine a defect and to update the defect information. The method of claim 21, And the control unit further includes a function of performing verification in the background. The method of claim 22, In the background of the verification, when the other application is not running, the verification proceeds, And stop verification when the application program is executed, and start verification again after the application program is terminated.

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