JP4888153B2 - Multi-layer optical disk and optical disk apparatus compatible with multilayer optical disk - Google Patents

Description

  The present invention relates to a multilayer optical disc and an optical disc apparatus that can handle the multilayer optical disc.

  DVD, Blu-ray, HD-DVD and the like are known as multilayer optical disks. These multi-layer optical discs are two-layer discs that are defined by standards that conform to the current product. For example, as in Non-Patent Document 1, studies on four-layer and six-layer optical discs have been conducted.

  Moreover, as a background art of this technical field, there exists Unexamined-Japanese-Patent No. 2006-244658, for example. This publication describes that “recording is performed with stable recording quality on an optical disc having three or more recording layers”.

JP 2006-244658 A Optical Data Storage Topical Meeting 2006 Proceedings TuA3

  Conventionally, when creating a multilayer optical disc, an optical disc having the same number of layers as that of the optical disc is created, the quality of each layer is evaluated after the optical disc is created, and the number of layers satisfying a predetermined specification is the specification of the optical disc. If the number of layers is smaller, the optical disc must be discarded.

  In general, an optical disk having a multilayer structure is formed by alternately stacking recording layers and spacer layers positioned between the recording layers one by one. Each recording layer and spacer layer are designed and created so as to have desired characteristics. However, due to manufacturing variations and the like, there are cases where the specifications defined by the standards to which all the layers conform may not be satisfied.

  In general, the disk characteristics are often measured after the disk is created, and in this case, whether or not the entire disk satisfies the target specification cannot be determined until after the disk is created. Therefore, even if the layer cannot satisfy the target specification due to problems during the formation of the first layer, it cannot be detected that the layer is out of specification, so the subsequent layer formation work is continued. I have to. Then, after the creation of all the layers is completed, the disk characteristics are measured, and at this time, the existence of a layer out of specification is found for the first time. In this case, the disc must be disposed of, and the formation work for the second and subsequent layers after the disc formation is a wasteful operation.

  With respect to this point, Patent Document 1 and Non-Patent Document 1 do not take any consideration into consideration.

  An object of the present invention is to provide an easy-to-use multilayer optical disc and an optical disc apparatus that can handle the multilayer optical disc.

  The above object can be achieved by providing redundancy in the number of layers of the multilayer optical disk. Further, this can be achieved by providing a reproducing / recording means for the multilayer optical disc in the optical disc apparatus.

  According to the present invention, it is possible to provide an easy-to-use multilayer optical disc and an optical disc apparatus that can handle the multilayer optical disc.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram of a portion relating to a plurality of information recording layers and layer information recording areas, which is an optical disc having a plurality of information recording layers according to a first embodiment.

  In the following, a recording layer that satisfies the standard in light of the standard to which the optical disc complies will be referred to as an effective recording layer. Conventionally, the relationship of the number of recording layers physically present = the number of logical information recording layers = the number of information recording layers defined in the standards to which the standard complies was established. This includes the case where the relationship of the number of recording layers to be not.note.the number of logical information recording layers and the number of recording layers defined by the standard to be satisfied is established.

  An example will be described in which an optical disc having four layers as defined by the compliant standard is created. Here, since an optical disc having four logical recording layers is produced, an example in which an optical disc having five physical recording layers is produced is taken as an example. The number of physical recording layers need only be larger than the number of logical recording layers, and need not be five, for example, six or more.

  First, an optical disc having five physical recording layers is prepared. Various manufacturing processes are used for producing the optical disc, but the multi-layer disc producing process itself is not directly related to the present embodiment, and the description thereof is omitted.

  After producing an optical disk having five recording layers, it is measured whether each recording layer satisfies a predetermined performance defined by the standard to which it complies. After the measurement is completed, the standard value to be satisfied by each layer and the measurement value are compared for each layer, and the size of the measurement value margin with respect to the standard value is compared. This work is for determining the quality of each layer and ranking the layers in order from the layer with the largest margin and the highest performance.

  When the ranking of the layers is completed and all five of the five recording layers satisfy the standard, the four layers from the top of the margin size ranking are recommended or permitted to be used ( Hereinafter, it is set as a usable layer).

In addition, when four of the five recording layers satisfy the standard, four layers that satisfy the standard are set as usable layers.
The physical recording layer configuration (layer arrangement) of the optical disc and the logical recording layer configuration (layer arrangement) are generally associated with each other so that the order of the layer numbers is the same, but this is not necessarily the case. is not. For example, the physical recording layer having the largest margin is assigned to the first number of the logical recording layer, and the physical recording layer having the second largest margin is assigned to the next number of the logical recording layer. The layer numbers of the logical recording layers may be assigned in descending order. In this case, since a layer number having a large recording margin is assigned in the order of the layer number of the logical recording layer, it can be generally expected that the layer number can be associated with the recording quality. Therefore, it is possible to expect an effect that the layers can be used properly from the viewpoint of necessary recording quality, reliability, and the like.

  Next, the recording layer information for identifying the physical information storage layer set as the logical information storage layer and the physical information storage layer not set as the logical information storage layer is used as the layer information of the optical disc. Record in the recording area.

  The recording layer information may be correspondence information indicating the correspondence between the physical information recording layer and the logical information recording layer.

  Here, the recording layer information only needs to be recorded in a form that can be read by an optical disc apparatus corresponding to a multilayer optical disc. For example, the recording layer information is conventionally recorded in a predetermined format in an information recording area known as a Burst Cutting Area (hereinafter referred to as BCA). Can be recorded. This can reduce the possibility that the user accidentally erases the recording layer information while ensuring compatibility with the current optical disc apparatus.

  Further, when the recording layer information is written on the layer closest to the light beam incident surface of the optical disc, the focus pull-in can be processed quickly, and the processing time during reproduction can be reduced.

  In addition, when the recording layer information is written in the layer farthest from the light beam incident surface of the optical disc, the recording layer does not need to transmit laser light unlike other recording layers, so the degree of freedom in designing the recording layer is increased. In general, it is easy to obtain a reproduction signal that is better than that of other recording layers, so that the reliability of the recording layer information can be increased.

  Further, when the recording layer information is described in all the layers, the recording layer information can be quickly obtained regardless of which layer the optical pickup is in.

  FIG. 3 shows an example in which recording layer information exists in two layers, the layer closest to the light beam incident surface of the optical disc and the layer farthest from the optical disc. The same usable layer information is recorded in the region for recording usable layer information in the layer information recording region of each of layer 1 and layer 5. In this case, since there is a plurality of usable layer information, it is sufficient that either one of the usable layer information can be reproduced correctly, so even if one of the usable layer information becomes unreadable due to a defect or scratch on the disc, etc. Necessary processing can be performed using the usable layer information that has been successfully reproduced, and the effect of improving reliability can be obtained.

The recording layer information only needs to be recorded in a form that can be read by an optical disc apparatus compatible with a multilayer optical disc. For example, the recording layer information has a predetermined format in an information recording area for recording unique identification information (hereinafter referred to as ID information) of the optical disc. May be recorded.
FIG. 4 is a schematic diagram showing an example of a method for storing the recording layer information. The recording layer information is stored in a portion of the lead-in block that includes disc information. In addition, information indicating that the disc is a multilayer disc is also stored in the portion including the disc information.

  By providing redundancy in the number of layers of the multilayer optical disc in this way, even if one or more layers do not meet the specifications stipulated by the standards to which the standards are based, the entire optical disc can meet the specifications. Since it can be handled as a good product, it does not need to be discarded. Therefore, it is possible to improve the yield in disc production, and it is possible to reduce the environmental load associated with the disposal of defective products. Also, even if a disk manufacturer has a defective layer, the number of layers determined to be usable is clearly specified as the number of layers guaranteed by the manufacturer. For example, the higher the number of layers, the higher the price. You can set the price according to the number and sell it.

  FIG. 2 is a block diagram of an optical disc apparatus which is a second embodiment and can handle the disc of the first embodiment.

  First, a case where information is recorded on an optical disk will be described.

  A signal detected from the optical disk 1 using the optical pickup 2 is input to the front end circuit 3. In the front end circuit 3, analog signal processing is mainly performed to generate a servo signal 5, a wobble signal 6, and the like. The servo signal 5 output from the front end circuit 3 is input to the reproduction system signal processing circuit 7. The reproduction system signal processing circuit 7 mainly performs digital signal processing to generate a servo system drive signal 9. The servo drive signal 9 is input to the driver circuit 14. The driver circuit 14 performs power amplification and the like, and drives an actuator (not shown) inside the optical pickup 2, a motor (not shown) for moving the entire optical pickup, and a motor 15 for rotating the optical disc 1. To do. The wobble signal 6 is input to the recording system signal processing circuit 20. The recording system signal processing circuit 20 performs address detection and recording clock generation by digital signal processing, and these are used for recording information. The record information 17 is input from the external device 13 to the interface circuit 10 via the interface signal 12. The interface circuit 10 performs processing such as data buffering using the connected buffer memory 11, and inputs the recording information 17 to the recording signal processing circuit 20.

  When recording information on the optical disc, first, the identification information or correspondence information between the physical recording layer and the logical recording layer (hereinafter referred to as usable layer information) recorded on the optical disc 1 is read. In the present embodiment, usable layer information exists in BCA information and ID information, and therefore, such information is detected using the optical pickup 2. Next, necessary information is subjected to the detected information by the reproduction system signal processing circuit 7 or the recording system signal processing circuit 20 to reproduce the usable layer information. The reproduced usable layer information is sent to recording control program software operating on the host PC or operating system software having a recording control function, and stored in the recording layer information recording memory 100. Further, a physical information recording layer to be used for recording is determined according to the instruction of the recording control software. Information corresponding to the physical information recording layer determined as a recording target is sent to the optical disc recording / reproducing apparatus. In the optical disc recording / reproducing apparatus, based on the sent information, first, an interlayer access process is performed on the physical information recording layer to be recorded as necessary. Next, intra-layer access processing is performed on the OPC area in the physical information recording layer to be recorded, and processing such as test writing for determining recording power is performed. When the optimum recording power is determined, an in-layer access process is performed, an access is made to an address a predetermined amount before the desired recording start address, and the target recording start address is detected. When the target recording start address is detected, information recording is started on the physical information recording layer of the optical disc 1.

  Next, a case where information is reproduced from the optical disc will be described.

  A signal detected from the optical disk 1 using the optical pickup 2 is input to the front end circuit 3. The front end circuit 3 mainly performs analog signal processing to generate an RF signal 4, a servo signal 5, and the like. These signals output from the front end circuit 3 are input to the reproduction system signal processing circuit 7. The reproduction system signal processing circuit 7 mainly performs digital signal processing to generate reproduction information 8 and servo system drive signals 9. The reproduction information 8 is input to the interface circuit 10. The interface circuit 10 performs processing such as data buffering using the connected buffer memory 11 and outputs information to the external device 13 via the interface signal 12. On the other hand, the servo drive signal 9 is input to the driver circuit 14. The driver circuit 14 performs power amplification and the like, and drives an actuator (not shown) inside the optical pickup 2, a motor (not shown) for moving the entire optical pickup, and a motor 15 for rotating the optical disc 1. To do.

  When reproducing information from the optical disc, the BCA information and ID information recorded on the disc are first detected using the optical pickup 2. Next, necessary information is subjected to the detected information by the reproduction system signal processing circuit 7 or the recording system signal processing circuit 20 to reproduce the usable layer information. The reproduced usable layer information is sent to reproduction control program software operating on the host PC or operating system software having a reproduction control function, and stored in the recording layer information recording memory 100. Further, a physical information recording layer to be reproduced is determined according to the instruction of the reproduction control software. Information corresponding to the physical information recording layer determined as the reproduction target is sent to the optical disc recording / reproducing apparatus. The optical disk recording / reproducing apparatus first performs an interlayer access process on the physical information recording layer to be reproduced based on the transmitted information. Next, in-layer access processing is performed, and access is made to an address preceding by a predetermined amount from a desired reproduction start address. In the case of the reproduction process, the trial writing process for determining the recording power in the recording operation is not necessary, so the order of the interlayer access process and the intra-layer access process may be switched. When the target reproduction start address is reached, information reproduction from the physical information recording layer of the optical disc 1 is started.

  It should be noted that various processes and circuits such as tilt servo, spherical aberration correction, access, RF signal demodulation, error detection / correction, etc. other than the above are linked and operated in actual optical disc equipment. Since there is no direct relationship with the present invention, description thereof is omitted.

Schematic diagram of the optical disc in the first embodiment Block diagram of the optical disk apparatus in the second embodiment Schematic diagram of arrangement of layer information recording area and usable layer information of optical disc in first embodiment Schematic diagram showing an example of recording layer information storage method

Explanation of symbols

1: optical disc 2: optical pickup 3: front end circuit 7: reproduction system signal processing circuit 10: interface circuit 11: buffer memory 13: external device 14: driver circuit 15: motor 16: microcomputer 20: recording system signal processing circuit 100 : Recording layer information recording memory

Claims (6)

An optical disc having a plurality of information recording layers,
Having more physical information recording layers than the number of logical information recording layers defined in the standard to which the optical disc conforms,
Information regarding the availability of each layer of the physical information recording layer exists as recording layer information,
The recording layer information is obtained by associating a physical information recording layer with a layer whose quality satisfies a predetermined standard, and a logical information recording layer, and the disc manufacturer determines the number of layers whose quality satisfies the predetermined standard. Specified as the total number of guarantees,
The recording layer information exists in all logical information recording layers of the optical disc,
An optical disc capable of recording information on the logical information recording layer or reproducing information from the logical information recording layer. An optical disc having a plurality of information recording layers,
Having more physical information recording layers than the number of logical information recording layers defined in the standard to which the optical disc conforms,
Information regarding the availability of each layer of the physical information recording layer exists as recording layer information,
The recording layer information is obtained by associating a physical information recording layer with a layer whose quality satisfies a predetermined standard, and a logical information recording layer, and the disc manufacturer determines the number of layers whose quality satisfies the predetermined standard. Specified as the total number of guarantees,
The recording layer information exists in a Burst Cutting Area (hereinafter referred to as BCA),
An optical disc capable of recording information on the logical information recording layer or reproducing information from the logical information recording layer. An optical disc having a plurality of information recording layers,
Having more physical information recording layers than the number of logical information recording layers defined in the standard to which the optical disc conforms,
Information regarding the availability of each layer of the physical information recording layer exists as recording layer information,
The recording layer information is a physical information recording layer in which the quality satisfying a predetermined standard is associated with the logical information recording layer in order from the highest quality layer,
An optical disc capable of recording information on the logical information recording layer or reproducing information from the logical information recording layer. An optical disc having a plurality of information recording layers,
Having more physical information recording layers than the number of logical information recording layers defined in the standard to which the optical disc conforms,
Information regarding the availability of each layer of the physical information recording layer exists as recording layer information,
The recording layer information is a physical information recording layer in which the quality satisfying a predetermined standard is associated with the logical information recording layer in order from the highest quality layer,
The recording layer information exists in all logical information recording layers of the optical disc,
An optical disc capable of recording information on the logical information recording layer or reproducing information from the logical information recording layer. An optical disc having a plurality of information recording layers,
Having more physical information recording layers than the number of logical information recording layers defined in the standard to which the optical disc conforms,
Information regarding the availability of each layer of the physical information recording layer exists as recording layer information,
The recording layer information is a physical information recording layer in which the quality satisfying a predetermined standard is associated with the logical information recording layer in order from the highest quality layer,
The recording layer information exists in the BCA,
An optical disc capable of recording information on the logical information recording layer or reproducing information from the logical information recording layer. An optical disc having a plurality of information recording layers, and the optical disc has more physical information recording layers than the number of logical information recording layers defined by the standard to which it complies, and uses each physical information recording layer for each layer. An optical disc apparatus capable of mounting an optical disc in which information relating to availability exists as recording layer information, and the disc manufacturer guarantees the number of layers whose quality satisfies a predetermined standard ,
Writing means for writing information to the optical disc;
Reading means for reading information from the optical disc;
A memory for storing information read by the reading means;
Control means for controlling the writing means and the reading means;
Have
The control means reads the recording layer information from the optical disc by the reading means,
Storing the recording layer information in the memory, and controlling the writing means and the reading means based on the recording layer information stored in the memory;
Optical disk device.

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