JP2009176335A - Multilayer optical disk and optical disk apparatus capable of coping with same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer optical disk which is excellent in handleability, and an optical disk device capable of coping with the same. <P>SOLUTION: The object is achieved by providing redundancy to the number of layers of the multilayer optical disk. The object is achieved by providing a reproducing/recording means of the multilayer optical disk to the optical disk device. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 continues. I have to. After all layers have been created, measure the disk characteristics,
At this time, the existence of an out-of-specification layer 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.

  It is obvious from the purpose that the performance evaluation region of the optical disk for measuring and evaluating the performance to be satisfied by each layer exists in all physical recording layers. The position in the radial direction where the performance evaluation area exists is at least one of the inner and outer peripheral sides of the optical disc, preferably both the inner and outer peripheral sides. This is because the optical disc may have different characteristics depending on the position in the radial direction, and in order to improve the reliability of performance evaluation of each layer, it is desirable to perform evaluation on both the inner peripheral side and the outer peripheral side. is there. FIG. 5 shows an example of arrangement of performance evaluation areas in the above case.

  The performance evaluation area is not necessarily provided in an area where the optical disc apparatus can read or write, but may be an area where the optical disc apparatus can read or write. For example, in order to divert part of the area provided for Optimum Power Control (OPC) and part of the area provided as Drive Calibration Zone (DCZ) in the Blu-ray disc standard for this performance evaluation. It may be defined by a standard.

  The performance evaluation in the performance evaluation area is performed by, for example, recording a predetermined signal in a predetermined area in the performance evaluation area under one or more recording conditions, and then recording one signal recorded earlier. Alternatively, reproduction is performed under two or more predetermined conditions, and jitter, error rate, signal amplitude, asymmetry, resolution, and the like are measured at the time of reproduction, and evaluation is performed from these measured values by a predetermined method.

  The conditions defined at the time of recording are, for example, recording power, recording waveform, recording strategy, and the like. Further, the conditions defined at the time of reproduction are, for example, reproduction power, high frequency superposition modulation degree, servo condition, and the like.

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.

  For example, as the recording layer information, (1) if the physical information recording layer corresponding to the logical information recording layer number is associated, the logical information recording layer number can be used because it is continuous without a missing number. Since the number of recording layers is the same as the number of logical information recording layers, there is an advantage that the processing in the optical disk drive device can be easily performed. Further, (2) if the physical information recording layer number is associated with the corresponding logical information recording layer, there is an advantage that the correspondence with the physical layer position of the optical disk can be easily obtained. Further, (3) only the usable physical information recording layer number is used as the recording layer information, and the correspondence with the logical information recording layer is in the order of the usable physical information recording layer number and the logical information recording layer number. You may make it link. (4) Only the unusable physical information recording layer number is used as the recording layer information, and the correspondence with the logical information recording layer is determined from the number of physical information recording layers and the unusable physical information recording layer number. The obtained physical information recording layer number and the logical information recording layer number may be associated in this order.

  If the recording layer information cannot be read normally for some reason, there is a possibility that the operation of the optical disc apparatus will be hindered. Since the recording layer information is arranged so as to exist in an area that can be read by the optical disc apparatus, in the recordable optical disc apparatus, it is physically possible to record and erase in the area. Therefore, when the recording layer information is present in an area that can be recorded or erased by the optical disk device, it is desirable that the recording layer information be logically protected from operations such as recording and erasing of the optical disk device that may prevent normal reading. Therefore, in the standard to which the optical disc of the present invention complies, the recording operation or the erasing operation on the recording layer information area is prohibited, and only the reproduction should be permitted.

Here, the recording layer information is only required to be recorded in a form that can be read by an optical disc apparatus corresponding to a multilayer optical disc. 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 only necessary to reproduce one of the usable layer information correctly.
Even if one of the usable layer information cannot be read due to a disc defect or scratch, etc., it is possible to perform necessary processing using the usable layer information that could be reproduced normally, and to improve reliability An effect is 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 non-defective product, it does not have to be discarded. Therefore,
The yield in disc production can be improved, and the environmental burden associated with the disposal of defective products can be reduced. Also, even if a disk manufacturer has a defective layer, the number of layers that can be used 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, and the servo signal 5
, Wobble signal 6 and the like are generated. Servo signal 5 output from 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, etc.
It is 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 perform RF signal 4,
Servo signal 5 and the like are generated. 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. Interface circuit 10 is connected to buffer memory 1
1 is used to perform processing such as data buffering, and information is output 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 an actuator (
A motor (not shown) for moving the entire optical pickup and a motor 15 for rotating the optical disk 1 are driven.

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 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.

Next, a third embodiment will be described. The maximum value of the logical information recording layer is Nmax, the possible logical information recording layer value is N, the value of the physically existing recording layer is M, and N is Nmax or less and L or more The natural number of (L, M and N are natural numbers)
First, it is created as M = Nmax when the optical disc is manufactured.
If all the recording layers satisfy the specifications as a result of the disk characteristic evaluation, this optical disk is N = M, so management information necessary for an M (= Nmax = N) layer optical disk is set. If one recording layer does not satisfy the specification, this optical disc has N = M−1, and therefore management information necessary for an (M−1) layer optical disc is set. Similarly, since N = L can be obtained in the same manner, an optical disc having M physical recording layers is manufactured. It can be used as an optical disc.

From the above, if there is even one recording layer that does not meet the specifications in an optical disc having M physical recording layers, it has been necessary to discard the recording layer. However, according to this embodiment, N is L or more. If it is present, it can be used as an N-layer optical disc and can be distributed without being discarded.
Therefore, it has a feature that it is useful for reducing the cost by reducing the waste at the time of manufacturing the optical disc and improving the yield.

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 Schematic diagram showing an example of disk performance evaluation area layout

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 (11)

An optical disc having a plurality of information recording layers,
The optical disc has more information recording layers than the number of information recording layers defined by a compliant standard,
The optical disc is an optical disc capable of recording information in the number of information recording layers defined by a compliant standard. The optical disc according to claim 1,
Records which layers are available and which are unavailable,
optical disk. The optical disc according to claim 1,
There is an area to determine which layers are available and which are unavailable,
After recording a signal in the area, determine whether to use each layer from the result of reproducing the signal,
The judgment result is recorded,
optical disk. The optical disc according to claim 1,
Correspondence between the physical information recording layer of the optical disc and the information recording layer defined by the standard that conforms is recorded,
optical disk. The optical disc according to claim 4,
The correspondence is recorded in the information recording layer closest to the light beam incident surface when the disc is loaded into the apparatus.
optical disk. The optical disc according to claim 4,
The correspondence is recorded in the information recording layer farthest from the light beam incident surface when the disc is loaded into the apparatus.
optical disk. The optical disc according to claim 4,
The correspondence is recorded in each information recording layer,
optical disk. An optical disc apparatus capable of mounting an optical disc that has more information recording layers than the number of layers defined by a compliant standard and can record information in the number of information recording layers defined by the compliant 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 information on the recording layer from the optical disk by the reading means,
Controlling the information to be stored in the memory, and controlling the writing means and the reading means based on the information stored in the memory;
Optical disk device. The optical disc according to claim 2,
The area where which layer is usable and which layer is unusable is recorded,
An area in which the optical disc device can be played back in the standard that the optical disc complies with.
optical disk. The optical disc according to claim 4,
An area in which a correspondence relationship between a physical information recording layer of the optical disc and an information recording layer defined by a compliant standard is recorded,
An area in which the optical disc device can be played back in the standard that the optical disc complies with.
optical disk. An optical disc according to claim 3,
The area to determine which layers are available and which are unavailable is
The optical disc apparatus is an area where reproduction is not essential in the standard that the optical disc complies with.
optical disk.

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