JP6523535B2 - Method of manufacturing optical disk, method of recording optical disk, method of reproducing optical disk, and method of identifying optical disk - Google Patents

Description

The present invention related information layer of a plurality of different optical disks standard method of manufacturing an optical disc which is multilayered on one disk, optical disk recording method, reproducing method optical disc, and the identification method of the optical disc.

  In the field of information recording, research has been conducted on optical disks. This optical disc can be used for non-contact recording / reproduction, can realize inexpensive large-capacity files, and can be read-only, write-once, or rewritable depending on the application. It is widely applied to consumer use.

  In order to increase the capacity of the various optical disks described above, the size of information written in the form of tracks on the disk is reduced, and shortening of the wavelength of the laser light serving as a light source used for recording and reproduction, and an objective lens with a high numerical aperture This has been achieved by reducing the focused spot size at the focal plane by adopting.

  For example, in the case of a CD (compact disc), the disc substrate to be a light transmitting layer has a thickness of about 1.2 mm, a laser beam wavelength of about 780 nm, an objective lens numerical aperture (NA) of 0.45, and a capacity of 650 MB. In DVD (Digital Versatile Disc), the thickness of the disc substrate to be the light transmission layer is about 0.6 mm, the laser light wavelength is about 650 nm, the NA is 0.6, and the capacity is 4.7 GB. It has become. For example, a DVD is used as a disc having a thickness of 1.2 mm by bonding two disc substrates having a thickness of about 0.6 mm.

  Furthermore, in BD (Blu-ray Disc) having a high density, the laser light wavelength is about 405 nm, the NA is 0. 0, using an optical disc in which the thickness of the protective layer of the light transmission layer provided on the optical recording layer is reduced to 0.1 mm. By adopting 85, a large capacity of 23 GB or more is realized.

  Thus, while increasing the capacity of optical disks, various optical disk standards such as CD, DVD, and BD have been formulated. On the other hand, the optical disc recording and reproducing apparatus is generally compatible with recording and reproducing optical discs of a plurality of standards.

  For example, in the case of a DVD recording and reproducing apparatus, there is a product capable of recording and reproducing a CD in addition to recording and reproducing of a DVD. In the case of a BD recording and reproducing apparatus, recording and reproducing of a BD, recording and reproduction of a DVD, recording and reproduction of a CD There are products that can These compatible recording and reproducing apparatuses are highly convenient because they can record and reproduce optical disks of the conventional standard owned by the user, and play an important role in the smooth spread of the new standard.

  Although these disks conformed to the respective standards, there have been developed optical disks in which information layers of a plurality of different optical disk standards are multi-layered on one disk in order to enhance user convenience. (For example, refer to patent document 1.)

JP 2004-95005 A

  In the optical disc as described above, it is unclear whether another information layer exists while accessing an information layer, so it is urgent to need to read or record information of another information layer. If the problem arises, it takes time to access the designated another information layer.

  Further, in the optical disc as described above, since the type of one information layer is not recorded in another information layer, the information layer being accessed changes when reading and writing with compatible optical disc devices compatible with a plurality of optical disc standards. Each time the information layer is accessed and the type thereof is read, it is necessary to select the method of generating the tracking error signal according to the type of the information layer, and there is also a problem that the access takes time.

  An object of the present invention is to shorten an access time in an optical disc in which information layers complying with a plurality of different optical disc standards are multilayered in order to solve the problems as described above.

The method of manufacturing an optical disc according to the present invention is
A method of manufacturing an optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser beam, comprising:
Recording the presence or absence of a second information layer scanned by a second laser beam having a wavelength longer than that of the first laser beam in the management area;
Recording the presence or absence of a third information layer scanned by a third laser beam having a wavelength longer than that of the second laser beam in the management area;
Equipped with
The presence or absence of the second information layer is represented by 2-bit information 00 when the second information layer does not exist, and the presence or absence of the third information layer is two bits when the third information layer does not exist. It is characterized by the information 00 of
The optical disc recording method of the present invention is
An optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser beam, wherein the management area has a longer wavelength than the first laser light Information representing the presence or absence of the second information layer scanned by the second laser light and information representing the presence or absence of the third information layer scanned by the third laser beam having a wavelength longer than that of the second laser light A recording method of an optical disc having each of
Reading out each piece of information representing the presence or absence of the second and third information layers from the management area;
Identifying the presence or absence of the second and third information layers based on the respective information indicating the presence or absence of the read out second and third information layers;
Equipped with
When the information representing the presence or absence of the second information layer is represented by 2-bit information 00, it is identified that the second information layer does not exist, and the information representing the presence or absence of the third information layer is 2 bits It is characterized by identifying that the third information layer does not exist when represented by the information 00 of.
According to the optical disc identification method of the present invention,
An optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser light, wherein the management area has a wavelength longer than that of the first laser light. Information representing the presence or absence of the second information layer scanned by the second laser beam and information representing the presence or absence of the third information layer scanned by the third laser beam having a wavelength longer than that of the second laser beam In the identification method of the optical disc which each has,
Reading out each piece of information representing the presence or absence of the second and third information layers from the management area;
Identifying the presence or absence of the second and third information layers based on the respective information indicating the presence or absence of the read out second and third information layers;
Equipped with
When the information representing the presence or absence of the second information layer is represented by 2-bit information 00, it is identified that the second information layer does not exist, and the information representing the presence or absence of the third information layer is 2 bits It is characterized by identifying that the third information layer does not exist when represented by the information 00 of.
According to the optical disc reproducing method of the present invention,
An optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser light, wherein the management area has a wavelength longer than that of the first laser light. Information representing the presence or absence of the second information layer scanned by the second laser beam and information representing the presence or absence of the third information layer scanned by the third laser beam having a wavelength longer than that of the second laser beam In the reproduction method of the optical disc each having 2 bits,
Reading out each piece of information representing the presence or absence of the second and third information layers from the management area;
Reproducing the optical disc according to the respective information representing the presence or absence of the read second and third information layers;
Equipped with
When the information indicating the presence or absence of the second information layer is represented by 2-bit information 00, it is assumed that the second information layer does not exist, and the information indicating the presence or absence of the third information layer is 2 bits It is characterized in that the optical disc is reproduced on the assumption that the third information layer does not exist when it is represented by the information 00.

  According to the present invention, an access time can be shortened in an optical disc in which information layers based on a plurality of different optical disc standards are multilayered.

6 is a schematic diagram showing the state of the optical disc in the first embodiment and the optical disc apparatus which has accessed the information layer L1 of the optical disc. 6 is a schematic diagram showing the state of an optical disc in Embodiment 1 and an optical disc apparatus which has accessed information layer L2 of the optical disc. 7 is a schematic diagram showing the state of the optical disc in the first embodiment and the optical disc apparatus which has accessed the information layer L3 of the optical disc. FIG. 7 is a schematic view showing a management area of the information layer L1 of the optical disc in the first embodiment. FIG. 5 is a schematic view showing a data structure of an optical disc including an information field of a management area in the first embodiment. 5 is a conceptual diagram of an information field in a management area in Embodiment 1. FIG. FIG. 7 is a schematic view of information written on a track of the information layer L2 and a light collection spot in the first embodiment. FIG. 7 is a schematic view of information written in a track shape of the information layer L3 and a focused spot in the first embodiment. FIG. 7 is a flow chart showing a sequence for reading information on the type of each information layer in Embodiment 1. FIG. 7 is a flow diagram showing a sequence of reproducing another information layer using information on the type of each information layer in Embodiment 1. FIG. 17 is a schematic view showing a management area of the information layer L1 of the optical disc in the second embodiment. FIG. 16 is a conceptual diagram in a management area in Embodiment 2; FIG. 20 is a conceptual diagram in a management area in Embodiment 3; FIG. 18 is a block diagram showing the configuration of an inspection system for an optical disk device according to a fifth embodiment. FIG. 16 is a flowchart showing an inspection process in the inspection system of the optical disk device according to the fifth embodiment.

Embodiment 1
1 to 3 are schematic views showing the state of the optical disc and the optical disc apparatus accessed to the information layer of the optical disc in Embodiment 1 of the present invention, and FIG. 4 is a schematic view showing the management area of the information layer L1 of the optical disc in FIG. FIG. FIG. 5 is a schematic view showing the data structure of the optical disc including the information field of the management area. FIG. 6 is a conceptual view of an information field in the management area. FIG. 7 is a schematic view of information written on the track of the information layer L2 and a focused spot, and FIG. 8 is a schematic view of information written on the track of the information layer L3 and the focused spot. FIG. 9 is a flow chart showing a sequence for reading information of the type of each information layer. FIG. 10 is a flow chart showing a sequence for reproducing another information layer using information of the type of each information layer.

  Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. In FIG. 1, a plurality of information layers L 1, L 2 and L 3 of different optical disc standards are provided on the optical disc 1, and are stacked in the thickness direction of the optical disc 1. The information layers L1, L2 and L3 are arranged in this order at positions where the distance from the surface to the information layer is 0.1 mm, 0.6 mm and 1.2 mm. In addition, those information layers L1, L2 and L3 satisfy the optical disc standards of BD, DVD and CD in this order, the information layer L1 is the layer with the highest recording density, and the information layer L3 is the layer with the lowest recording density. I assume. Here, the case of the reproduction only type, the recordable type, and the reproduction only type will be described.

  The state of FIG. 1 shows a state in which the information layer L1 is accessed, and the light beam 3a emitted from the blue-violet semiconductor laser light source 2a of about 405 nm which is the shortest wavelength is collimated by the collimator lens 4a, and the prism 5a The light is reflected and condensed by the objective lens 6 onto the information layer L1 as a condensing spot 7a.

  The light beam 3a reflected by the information layer L1 reenters the objective lens 6. Thereafter, the light is transmitted through the prisms 5a, 5b and 5c, and is irradiated onto the light detector 9 by the sensor lens 8.

  The light detector 9 photoelectrically converts the received light beam and outputs the light beam to the signal processing means 10. The signal processing means 10 controls the light emission amount with respect to the light source 2a, generates a tracking error signal representing a relative position error between the focused spot and the track of the information layer, and outputs the information after signal processing to the image processing means 11. Output to the The video processing means 11 performs video processing and outputs.

  The optical disk apparatus 12 is configured including the light source 2a to the video processing means 11 described above, and according to an instruction from the host 13, recording and reproduction of information on the optical disk 1 are performed. The host 13 is a PC (Personal computer) that instructs the optical disk device 12 to record and / or reproduce information. Also, a video and audio reproduction apparatus that decodes the information read by the optical disk apparatus 12 and outputs video and audio, and / or codes video and audio information input externally and instructs the optical disk apparatus 12 to record It may be a voice recording device.

  The state shown in FIG. 2 shows a state in which the information layer L2 is accessed, and the light beam 3b emitted from the red semiconductor laser light source 2b having a wavelength of about 650 nm is collimated by the collimator lens 4b and reflected by the prism 5b to be the objective lens. 6, the light is focused on the information layer L2 as a focused spot 7b.

  At this time, the light flux 3b passes through the information layer L1. Therefore, in order not to affect the access of the information layer L2, the information layer L1 is set in material and structure in consideration of physical characteristics such as transmittance and reflectance for a light flux having a wavelength of about 650 nm.

  The light beam 3 b reflected by the information layer L 2 reenters the objective lens 6. Thereafter, the light is transmitted through the prisms 5a, 5b and 5c, and is irradiated onto the light detector 9 by the sensor lens 8. The signal processing unit 10 and the video processing unit 11 perform the same operation and thus will be omitted. In FIG. 2, the signal processing means 10 controls the light source 2b.

  The state shown in FIG. 3 shows a state in which the information layer L3 is accessed, and the light beam 3c emitted from the infrared semiconductor laser light source 2c having a wavelength of about 780 nm is collimated by the collimator lens 4c and is reflected by the prism 5c. A lens 6 focuses light onto the information layer L3 as a focused spot 7c.

  At this time, the light flux 3c passes through the information layers L1 and L2. Therefore, the information layers L1 and L2 are set in materials and structures in consideration of physical characteristics such as transmittance and reflectance for light flux having a wavelength of about 780 nm so as not to affect access to the information layer L3.

  The light beam 3c reflected by the information layer L3 reenters the objective lens 6. Thereafter, the light is transmitted through the prisms 5a, 5b and 5c, and is irradiated onto the light detector 9 by the sensor lens 8. The signal processing unit 10 and the video processing unit 11 perform the same operation and thus will be omitted. In FIG. 3, the signal processing means 10 controls the light source 2c.

  In FIGS. 4 and 5, the management area 14 provided in the information layer L1 of the optical disc 1 is provided at the innermost circumferential position of the optical disc 1, and the user data area 15 is provided except for the management area 14. The information field 16 of the management area 14 has information indicating the type of each information layer. When the optical disc apparatus 12 reads out the information field 16, information representing the type of each information layer is obtained.

  FIG. 6 is a conceptual view of the information field 16. Each area S1, S2, S3 in the information field 16 is a bit representing the type of the information layer L1, L2, L3, respectively. The areas S1, S2 and S3 are each composed of 2 bits, and a total of 6 bits are used. The above bit is 01 if the information layer is a read only type and 10 if the information layer is a recordable type. If there is no information layer, it is represented by 00. Therefore, the areas S1, S2, and S3 in the first embodiment are recorded as 01, 10, and 01, respectively.

  FIG. 7 shows a diagram of information and a focused spot 7b written in the form of a track in which the information layer is recordable. The recordable type has tracks called lands 17 and grooves 18. Information is recorded as a recording mark 19 using chemical change or shape change of the material. In the case of the recordable information layer, the well-known Differential Push-Pull method (DPP method) is used to generate the tracking error signal. In this method, a light beam is divided into three beams and condensed on an information layer, and the reflected light is received by three two-divided light detectors and calculated to obtain a tracking error signal.

  FIG. 8 shows a diagram of information and a focused spot 7c written in a track shape in which the information layer is a reproduction only type. In the reproduction only type, information is recorded by minute holes called pits 20. In this case, a known differential phase detection method (DPD method) is used to generate a tracking error signal. This is a method of collecting a luminous flux on an information layer, receiving the reflected light by one four-divided photodetector and calculating it to obtain a tracking error signal.

  In FIG. 9, when the optical disk 1 is inserted into the optical disk drive 12 (ST1), the optical disk drive 12 reads the information field 16 in the management area 14 in the information layer L1 on the optical disk 1 (ST2), Information representing the type of each information layer L1, L2, L3 is obtained, the information is held in the signal processing means 10 (ST3), and the process is ended (ST4), and a standby state for waiting for an instruction from the host 13 is entered.

  In FIG. 10, in response to a reproduction instruction of the information layer L2 from the host 13 (ST10), the optical disk apparatus 12 reads the type of the information layer L2 held inside the signal processing means 10 as described above according to a sequence. (ST11). Since the information layer L2 is not a read-only type (FALSE in ST12) and is a recordable type (TRUE in ST13), a DPP method suitable for the recordable type information layer L2 is selected and simultaneously it is suitable for the information layer L2 The laser power of the wavelength laser is set, a tracking error signal is generated (ST14), and information is reproduced from the information layer L2 (ST15).

  Similarly, also in response to a reproduction instruction of the information layer L3 from the host 13 (ST10), the type of the information layer L3 held inside the signal processing means 10 is read out according to the same sequence as FIG. 10 as described above. (ST11). Since the information layer L3 is a read only type (TRUE in ST12), the DPD method suitable for the read only type information layer L3 is selected, and at the same time the laser power of the laser of the wavelength suitable for the information layer L3 is set and tracking An error signal is generated (ST16), and information is reproduced from the information layer L3 (ST17).

In response to a reproduction instruction from the host 13, the type of the information layer L3 held inside the signal processing means 10 is neither a reproduction only type nor a recordable type (when both ST12 and ST13 are FALSE), the optical disc apparatus If it is unrecognizable information, it is returned to the host 13 that the information layer to which the reproduction instruction is issued is inaccessible (ST18), and the process ends (ST19), and waits for the next instruction from the host 13.
In FIG. 10, any one of steps ST12 and ST13 for determining whether the type of the information layer is a reproduction only type or a recordable type may be earlier.
Further, although FIG. 10 shows the case where the host 13 issues the reproduction instruction, the recording layer may also receive the recording instruction based on the information indicating the type of the information layer. On the other hand, the access time can be shortened and appropriate recording operation can be performed.

In the present embodiment, an optical disc apparatus identifies another type of information layer by recording information indicating the type of another information layer in an optical disc in which information layers based on a plurality of different optical disc standards are multilayered. It is easy to do, and the access time can be shortened.
Further, by recording this information in the management area of the information layer with the highest recording density, it is expected that the information layer will be used the most frequently, so that the optical disc device can be reliably read and held.
Furthermore, when recording and reproducing information on such an optical disc, the optical disc apparatus previously uses the laser power of the wavelength of the laser suitable for the layer to be accessed based on the information indicating the type of the information layer. The access time can be shortened by predetermining a method of generating tracking error signals that can be set to appropriate values and that represent relative positional errors in the cross track direction of a plurality of focused spots and track information. it can.

Second Embodiment
The second embodiment of the present invention is the same as the first embodiment of the present invention in FIGS. 1 to 5 and FIGS. 7 to 10, and the handling of the area in the management area in FIG. ing.

  In FIG. 11, the optical disc comprises a management area 14a located on the inner circumference side and a user data area 15a located on the outer circumference side, and information indicating the presence or absence of another information layer in the management area 14a records And a type area 22 in which information representing the type of another information layer is recorded. In FIG. 12, the areas T2 and T3 of the display area 21 each record information indicating the presence or absence of the information layers L2 and L3 illustrated in FIG. Although the region T4 is not illustrated in the optical disk 1, an information layer based on another optical disk standard other than BD using a blue-violet semiconductor laser having a wavelength of about 405 nm as a light source, or another standard that will be developed in the future Indicates the presence or absence of Each of the areas T2, T3 and T4 has an information layer of 1 bit, and the display area 21 is constituted by a total of 3 bits. The above bits are represented by 1 and 0 respectively with and without the information layer.

  In FIG. 12, the areas U2, U3 and U4 of the type area 22 are associated corresponding to the information layers represented by the areas T2, T3 and T4 of the display area 21, and the information indicating the type of each information layer is recorded It is an area that is That is, the regions U2, U3, and U4 respectively indicate the types of information layers in the regions T2, T3, and T4 when the information layers exist (bit 1). Each of the areas U2, U3 and U4 has 2 bits of information, and the type area 22 consists of a total of 6 bits. Each of the above two bits is represented by 00 when the information layer is a read only type, 01 when it is a write-once type, and 10 when it is a rewrite type. The write-once type includes DVD-R and + R which can be added but can not be rewritten, and their two-layer standards. Further, the rewrite type includes a two-layer standard of DVD-RW or + RW or a DVD-RAM. If no information layer exists in any of the areas T2, T3 and T4 (bit 0), 00 corresponding to reserve (reserved area) is assigned to the corresponding areas U2, U3 and U4. In this case, apparently, the same bit as when the information layer is of read-only type is used, but if any of the areas T2, T3 and T4 is bit 0, the corresponding area U2, U3 and U4 corresponds to it. There is no particular problem because it does not read Alternatively, bits other than the above (for example, 11) may be allocated.

When an optical disc is inserted, the optical disc apparatus reads information areas L2, T3 and T4 of the display area 21 in the management area 14a in the information layer L1 on the optical disc, thereby making the information layers L2, L3 and other standards Obtain information that indicates the presence or absence of a compliant information layer. Next, when the optical disc apparatus indicates the presence / absence of the corresponding information layer among the areas T2, T3 and T4 (bit 1), it reads the areas U2, U3 and U4 of the type area 22 in the management information 14a Information representing the type of information layer is obtained, and the information is held in the signal processing means 10. The subsequent operation is the same as the flow shown in FIG.
The optical disc apparatus reads only the corresponding information from the areas U2, U3 and U4 of the type area 22 only when the information obtained from the areas T2, T3 and T4 indicates the presence of the information layer (bit 1). Can be designed. However, even if the information obtained from the regions T2, T3 and T4 is either the presence or absence of the information layer, all of the regions U2, U3 and U4 of the type region 22 may be designed to be read.

If there is an information layer corresponding to the region T4 and this information layer conforms to an optical disk standard other than BD using a blue-violet semiconductor laser having a wavelength of about 405 nm as a light source, the shortest wavelength is about 405 nm A plurality of information layers (two of the information layer L1 and the information layer corresponding to the region T4) corresponding to T. are included, but the display region 21 and the type region 22 are provided at least in the information layer L1. However, it may be provided in both of the information layer corresponding to the area T4 as well as the information layer L1.
In the future, the area T4 and the area U4 may be freed as special information as reserve in case a new standard is formulated. In this case, the display area 21 and the type area 22 hold information on two types of information layers, the information layers L2 and L3.

  The two bits allocated to the area U2 corresponding to the DVD layer may be classified based on the type of structure of the information track. In this case, classification can be made based on the periodic structure of the information track such as the wobble frequency. For example, in the case of reproduction only type such as DVD-ROM with only pre-pit and no wobble, 00, 01 in the case of DVD-R or DVD-RW with wobble, wobble exists but the wobble frequency is DVD-R or DVD In the case of DVD + R or DVD + RW higher than -RW, 10 may be allocated, and in the case of a DVD-RAM in which the header is formed radially offset on the land / groove single spiral structure and wobble is not present, 11 may be allocated. In the case of the DVD layer, since the periodic structure of the information track uses the same format for each classification, the characteristics of the wobble signal detection circuit (circuit for detecting the frequency of the periodic structure) such as a band pass filter are accessed It is possible to set the disk rotation speed to a target value quickly and reduce the access time.

In the present embodiment, in an optical disc in which information layers based on a plurality of different optical disc standards are multilayered, the optical disc apparatus identifies the presence or absence of another information layer by recording information indicating the presence or absence of another information layer. This makes it easy to reduce access time.
Furthermore, in addition to the display area 21 storing information indicating the presence or absence of another information layer in the management area of the optical disc, a type area 22 storing information indicating the type of the information layer is provided. The information of the display area 21 and the information of the type area 22 have a hierarchical structure in association with the information of the area 22. Therefore, in the future, when providing another area in the management area 15 or when adding another type of information layer, it is possible to ensure extensibility using the hierarchical structure.

Also, by recording such information in the management area of the information layer with the highest recording density, this information layer is expected to have the highest frequency of use, so that the optical disk device can be reliably read and held. .
Furthermore, when recording and reproducing information on such an optical disc, the optical disc apparatus previously sets the laser power of the laser of the wavelength suitable for the layer to be accessed to an appropriate value based on the above information. The access time can be shortened by predetermining a tracking error signal generation method that can be set and that represents relative positional errors in the direction crossing a plurality of tracks of the focused spot and the information written on the track.

Third Embodiment
The third embodiment is an embodiment in which there are at most two types of information layers in the optical disc 1 including the type of L1 layer. 1 to 5 and FIGS. 7 to 11 are the same as the second embodiment of the present invention, and the handling of the display area 21 and the type area 22 in FIG. 12 of the second embodiment is different.

In FIG. 13, areas T2, T3 and T4 of the display area 21 are the same as in FIG.
The area V1 of the type area 22 indicates the type of another information layer when there is another information layer other than the information layer L1. The type area 22 has information of only 2 bits of the area V1. The above two bits are represented by 00 when the information layer is a read only type, 01 when it is a write-once type, and 10 when it is a rewrite type. The write-once type includes DVD-R, + R, their two-layer standard, and the like. The rewrite type includes a dual layer standard of DVD-RW and + RW, a DVD-RAM, and the like.
For example, in the case where the information layer L1 is a recordable type including one or two layers, and both the information layers L2 and L3 are read-only type and there is no other layer (T2 = 1, T3 = 1, T4 = 0) The area V1 is the bit 00. Further, when the information layer L1 is a reproduction only type including one layer or two layers, and the information layer L2 is a reproduction only type and there is no other layer (T2 = 1, T3 = 0, T4 = 0), the region V1 Is a bit 00.

As described above, in the optical disc 1, when at least one of the areas T2, T3 and T4 of the display area 21 is the bit 1 and there is one type of information layer indicating this bit 1, or in the areas T2, T3 and T4. When the area of bit 1 is only one layer, the type area 22 can be set to 2 bits, so that the information bit can be saved as compared with the second embodiment. In particular, it is expected that only one of the information layers L2 and L3 exists and an optical disc using this layer as a read-only type is expected to meet the market needs. Therefore, an optical disc in which the information layer L2 or L3 is a read-only type In a situation where only production / sales are to be made, only two bits of the area V1 are sufficient for the type area 22.
As described in the second embodiment, the region V1 may be classified based on the type of information track structure such as the presence or absence of wobble.

In the present embodiment, the case where the area V1 of the type area 22 is information of only 2 bits is shown, but information of only 1 bit may be used to further save information bits. In this case, for example, the reproduction only type can be represented by 0, and in other cases, the write-once type or the rewrite type can be represented by 1. Alternatively, classification may be made based on the type of structure of the information track, such as 0 in the case of no wobble and 1 in the case of wobble.
Furthermore, as described above, when the area V1 for storing information representing the information layer is 1 bit and the area T4 of the display area 21 of FIG. 13 is reserved without special information as reserve, it is used as a reserve area. Since the area T4 is originally allocated as one bit, one bit of the area V1, which is information representing the information layer, may be allocated to the area T4. By doing this, information bits can be further saved, and the display area 21 and the type area 22 can be arranged adjacent to each other. As a result, the access time of the disk device can be further shortened.
The other effects are the same as the effects shown in the first and second embodiments.

Fourth Embodiment
In consideration of the effective use of the present bits in the future, it is also possible to assign 00 or 0 as all reserve in the type area 22 of the second and third embodiments without assigning to any information in particular. Further, as described in the third embodiment, in a situation where only the optical disc in which the information layers L2 and L3 are the reproduction only type is manufactured and sold, the type area 22 does not need to assign the information indicating the type of the information layer. Sometimes it is good.
However, if there are changes in the market such as the manufacture and sale of various mixed type optical disks as well as optical disks in which the information layers L2 and L3 are read-only type in the future, the bits of the type area 22 When it is necessary to use to represent the type, the information layer L2 or L3 is most frequently used 00 or 0 allocated to the type area 22 in order to ensure compatibility with the optical disc of read-only type. Assign to playback-only type. Further, even in the case where this bit is used as a bit representing a completely different item, for the same reason, it is necessary to devise to reserve 00 or 0 allocated to the type area 22 at reserve.
In the case of the present embodiment, the information is only the display area in which the information indicating the presence or absence of another information layer is stored, but for the optical disc device, it is possible to identify the presence or absence of another information layer by this information. Therefore, it contributes to shortening of access time.

Embodiment 5
FIG. 14 is a diagram showing a configuration of an inspection system for inspecting the reproduction operation of the optical disc apparatus 1 for reproducing an optical disc in which information layers of a plurality of different optical disc standards are multilayered described in the first to fourth embodiments. The system shown in FIG. 14 includes an optical disk apparatus 100 to be inspected, a computer 200 connected to the optical disk reproducing apparatus, and a monitor 300 for displaying inspection results and the like. The computer 200 includes an input unit 400 such as a keyboard.

  An inspection program for inspecting the reproduction operation of the optical disc device 1 is stored in a memory in the computer 200, and the computer 200 executes the inspection program and communicates with the optical disc device 1 by The reproduction operation of the optical disc apparatus 1 is inspected. In the inspection of the optical disc apparatus 1, when the optical disc described in the first to fourth embodiments is inserted, the information related to the other information layer recorded in the management area of the information layer with the highest recording density is read This is done by checking whether or not access can be accurately made.

  Hereinafter, an inspection method of the disc reproducing apparatus in the inspection system according to the present embodiment will be described. Here, the case where an optical disc in which a BD-ROM layer and a DVD-ROM layer are multi-layered in one disc is used as a test disc for reproduction operation (hereinafter, "test disc") will be described.

  First, the test disc is mounted on the optical disc apparatus 1 to be inspected, rotated at 1 × speed, and a flag indicating the type of each information layer recorded in the management area of the BD-ROM layer of the test disc is detected. In this case, if the optical disc apparatus 1 operates normally, information indicating that the other information layer is a DVD-ROM layer is detected. If information indicating that the other information layer is a DVD-ROM layer is detected, the computer 200 transmits a command to the optical disc apparatus 1 to access the other information layer. If the optical disk device 1 normally accesses the DVD-ROM layer which is another information layer, the inspection is completed.

FIG. 15 is a flowchart showing the details of the inspection process described above.
The computer 200 transmits a command of "disk start" (step S101), and the optical disk apparatus 1 receives the command, rotates the disk, and performs disk determination (step S102). If the disk can not be determined and the optical disk apparatus 1 outputs an error signal, the computer 200 displays "abnormal" as the inspection result on the monitor 300 (step S115).

When the disc discrimination operation is completed and the preparation for reading out the data is completed (step S103), the computer 200 transmits an "acquisition of management area information" command (step S104).
The optical disc apparatus 1 acquires information on the management area (step S105), and determines whether the type of the information layer currently accessed is a BD-ROM layer (step S106). When the flag indicating the BD-ROM layer is not detected from the information of the management area, the computer 200 displays "abnormal" as the inspection result on the monitor 300 (step S115).

  When the flag indicating the BD-ROM layer is detected from the information of the management area, it is determined from the flag indicating the type of the other information layer whether the other information layer is the DVD-ROM layer (step S107). If the flag indicating that the other information layer is the DVD-ROM layer is not detected from the information of the management area, the computer 200 displays "abnormal" as an inspection result on the monitor 300 (step S115). If a flag indicating that the other information layer is a DVD-ROM layer is detected, the computer 200 transmits a "DVD layer access" command (step S108).

In response to the command from the computer 200, the optical disc apparatus 1 performs the access operation to the DVD-ROM layer, and transmits an error signal to the computer 200 when the access operation is not normally performed (step S109). When an error signal is transmitted, the computer 200 displays "abnormal" as a test result on the monitor 300 (step S115).
When access to the DVD-ROM layer is normally completed and preparation for reading data is completed (step S110), the computer 200 transmits an "acquisition of management area information" command to the optical disc apparatus 1 (step S111).

The optical disc apparatus 1 acquires information on the management area (step S112), and determines whether the type of the information layer currently being accessed is a DVD-ROM layer (step S113). When the flag indicating the DVD-ROM layer is not detected from the information of the management area, the computer 200 displays "abnormal" as the inspection result on the monitor 300 (step S115).
When the flag indicating the DVD-ROM layer is detected from the information of the management area, the computer 200 displays "no abnormality" as the inspection result on the monitor 300 (step S114), and the inspection is completed.

  According to the inspection method of the optical disk apparatus described above, whether or not the optical disk apparatus can normally perform the reproduction operation when the optical disk having the multiple information layers conforming to a plurality of different optical disk standards is inserted. Can be performed automatically.

Reference Signs List 1 optical disc 2a blue-violet semiconductor laser light source 2b red semiconductor laser light source 2c infrared semiconductor laser light source 3a luminous flux of blue-violet semiconductor laser light source 3b luminous flux of red semiconductor laser light source 3c luminous flux of infrared semiconductor laser light source 4a , 4b, 4c collimating lens, 5a, 5b, 5c prism, 6 objective lens, 7a focusing spot of blue-violet semiconductor laser light source, 7b focusing spot of red semiconductor laser light source, 7c focusing spot of infrared semiconductor laser light source, 8 sensor lens, 9 light detector, 10 signal processing means, 11 image processing means, 12 optical disk apparatus, 13 host, 14, 14a management area, 15, 15a user data area, 16 information field, 17 land, 18 groove, 19 Recording mark, 20 pits, 21 display areas, 2 Type region, 100 an optical disk apparatus, 200 computer, 300 monitor.

Claims (4)

A method of manufacturing an optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser beam, comprising:
Recording the presence or absence of a second information layer scanned by a second laser beam having a wavelength longer than that of the first laser beam in the management area;
Recording the presence or absence of a third information layer scanned by a third laser beam having a wavelength longer than that of the second laser beam in the management area;
Equipped with
The presence or absence of the second information layer is represented by 2-bit information 00 when the second information layer does not exist, and the presence or absence of the third information layer is two bits when the third information layer does not exist. A method of manufacturing an optical disc characterized by the information 00 of An optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser beam, wherein the management area has a longer wavelength than the first laser light Information representing the presence or absence of the second information layer scanned by the second laser light and information representing the presence or absence of the third information layer scanned by the third laser beam having a wavelength longer than that of the second laser light A recording method of an optical disc having each of
Reading out each piece of information representing the presence or absence of the second and third information layers from the management area;
Identifying the presence or absence of the second and third information layers based on the respective information indicating the presence or absence of the read out second and third information layers;
Equipped with
When the information representing the presence or absence of the second information layer is represented by 2-bit information 00, it is identified that the second information layer does not exist, and the information representing the presence or absence of the third information layer is 2 bits A method of recording on an optical disc characterized by identifying that the third information layer does not exist when it is represented by the information 00 of. An optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser light, wherein the management area has a wavelength longer than that of the first laser light. Information representing the presence or absence of the second information layer scanned by the second laser beam and information representing the presence or absence of the third information layer scanned by the third laser beam having a wavelength longer than that of the second laser beam In the identification method of the optical disc which each has,
Reading out each piece of information representing the presence or absence of the second and third information layers from the management area;
Identifying the presence or absence of the second and third information layers based on the respective information indicating the presence or absence of the read out second and third information layers;
Equipped with
When the information representing the presence or absence of the second information layer is represented by 2-bit information 00, it is identified that the second information layer does not exist, and the information representing the presence or absence of the third information layer is 2 bits A method of identifying an optical disc characterized by identifying that the third information layer does not exist when it is represented by the information 00 of. An optical disc comprising a BD layer as a first information layer having a management area on a circumferential track scanned by a first laser light, wherein the management area has a wavelength longer than that of the first laser light. Information representing the presence or absence of the second information layer scanned by the second laser beam and information representing the presence or absence of the third information layer scanned by the third laser beam having a wavelength longer than that of the second laser beam In the reproduction method of the optical disc each having 2 bits,
Reading out each piece of information representing the presence or absence of the second and third information layers from the management area;
Reproducing the optical disc according to the respective information representing the presence or absence of the read second and third information layers;
Equipped with
When the information indicating the presence or absence of the second information layer is represented by 2-bit information 00, it is assumed that the second information layer does not exist, and the information indicating the presence or absence of the third information layer is 2 bits Play how the optical disc, characterized in that for reproducing the optical disc as the third information layer is not present when expressed by the information 00.

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