JP2003016648A - Method for recording information on information medium having multilayer recording layer and device using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recording information by which an excellent recording is performed on a information medium having a multiplayer recording layer by using an optical system having an objective lens having a high numerical aperture(NA). SOLUTION: A system control part performs administration (ST24 yes, ST26, ST28) in a way that a recording on another layer is not performed until a layer under recording state (a crystallized state in the case of a phase change recording layer) is fully recorded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of recording information on an information medium having a multi-layer recording layer and an apparatus using this method. In particular, the present invention relates to an information recording method using an optical disk having two or more phase change recording layers on one side and an apparatus using this method.

[0002]

2. Description of the Related Art As a medium for storing video information (for example, NTSC video image) having a large data size, D
Large-capacity optical disks such as VD-RAM, DVD-RW, and DVD-R have been put to practical use. In recent years, the information to be recorded (for example, digital high-definition video) has become larger, and there is a demand for further increasing the capacity of the storage medium. In order to meet this demand, along with the shortening of the wavelength of the recording laser, the multilayering of the recording layer (in particular, the multilayering seen from one side of the disk) is being promoted.

[0003]

When the recording layers are multi-layered, the recording laser light must pass through one recording layer (upper recording layer) and then reach the other recording layer (lower recording layer). This creates problems that must be addressed.
Hereinafter, this problem will be described by taking as an example a case where recording is performed on a "narrow track pitch / high linear density high density DVD-RAM disk" having a single-sided n layer (n ≧ 2) whose recording surface is protected by a thin protective layer. To do.

For example, when recording is performed on the above high density DVD-RAM disk by using the optical head PUH having a blue laser diode LD and an objective lens having a large numerical aperture NA, recording on the entire surface of the layer where recording has started is completed. Therefore, it is necessary to record on the other layer. The reason is that the objective lens of the high density DVD-RAM disc has a high N
Since A is and the protective layer is thin, the focus position of the laser beam spot and the like have a small interlayer distance adjusted by the optical system at the time of reproduction, and the influence between layers at the time of recording becomes large. is there. Specifically, when recording is performed on the lower recording layer through the upper recording layer, the physical state of the upper recording layer is not constant (for example, in the phase change recording layer, the crystallization state / The crystallized state and the non-crystallized state / amorphized state of the unrecorded portion are mixed) and the recording laser light is nonuniform in the upper recording layer (transmissivity / reflectance is nonuniform). , Which prevents normal recording on the lower recording layer.

In a video recording / reproducing apparatus, when recording is sequentially performed on each recording layer from the start end of an unrecorded raw disc, a large amount of data is continuously recorded, so that the non-uniform state is unlikely to be created. Therefore, the above-mentioned “non-uniform state of the upper recording layer” does not affect the recording, so that the problem is small. But,
Since the writing / erasing is repeated in the use in a computer, the above "influence of the non-uniform state of the upper recording layer at the time of recording on the lower recording layer" occurs, so that all the layers during recording (upper recording layer) It is necessary to manage so as not to record on another layer (lower recording layer) until the recording state is reached. In video recording as well, when one multi-layer disc is used for repetitive recording and reproduction, similar management is required. However, there has been no technology for performing such management in the past.

Regarding write / erase management of an optical disk,
For example, there is an optical disk recording device disclosed in Japanese Patent Laid-Open No. 11-007726. In the invention of this publication, a packet can be additionally written in a correct format on an optical disc in which data is pseudo erased. However, in the invention of this publication, management for suppressing the above-mentioned "influence at the time of recording on the lower recording layer due to the non-uniform state of the upper recording layer" is applied to the optical disc having two or more phase change recording layers on one side. not going.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an information medium having a multilayer recording layer by using an optical system having a high NA objective lens (for example, a single-sided multilayer having a thin protective layer and a small interlayer distance). It is an object of the present invention to provide an information recording method that enables good recording on an optical disk.

Another object of the invention is to provide an apparatus using the above method.

[0009]

In order to achieve the above object, in the information recording method of the present invention, all the layers being recorded (for example, the second recording layer 112 in FIG. 1) are in the recording state (in the phase change recording layer, Other layers (for example, as shown in FIG.
Management such that recording is not performed on the third recording layer 113) (YES in steps ST24, ST26, and ST28 in FIG. 3).
A system control unit (for example, MPU in 210 of FIG. 2)
Do.

In other words, an information medium (100) having two or more multi-layer recording layers (111 to 113) as recording targets is used, and information is recorded on the multi-layer recording layers by a light beam. According to the recording method, when recording is performed, all the specific recording layers (for example, 112) are in the recorded state (Yes in step ST24), and then the recording is performed for the other recording layers (for example, 113) (step ST).
26 Yes, ST28, ST20).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an information medium having a multi-layer recording layer according to an embodiment of the present invention (optical disk 1 having a single-sided three-layer structure).
It is a figure explaining the structure of (00). Optical disc 1 of FIG.
In No. 00, the phase change recording layer (third recording layer) 113 is formed on the substrate 104, and the phase change recording layer (second recording layer) 112 is formed on the third recording layer 113 via the intermediate layer 103. Then, a phase change recording layer (first recording layer) 111 is formed on the second recording layer 112 via the intermediate layer 102, and a protective layer is formed on the first recording layer 111 (the surface side serving as a laser receiving surface). 101 is provided. The protective layer 101 is composed of, for example, a transparent film having a thickness of about 100 μm. Recording layers 111 to
Each of 113 can be formed of a phase change recording layer. The intermediate layers 102 and 103 are, for example, the protective layer 101.
Suitable thickness equal to or less than (10 μm to 100 μm
Have a degree). Protective layer 101 and intermediate layers 102, 10
The refractive index of 3 is, for example, around 1.6 (about ± 10% thereof)
To be chosen.

When the disc 100 of FIG. 1 is a single-sided disc, the thickness from the lower side surface of the substrate 104 to the upper side surface of the protective layer 101 is set to about 1.2 mm as in the existing DVD disc. Alternatively, the thickness of the half substrate from the lower side surface of the substrate 104 to the upper side surface of the protective layer 101 is set to about 0.6 mm, which is the same as the half substrate before bonding of the current DVD disc, and the thickness on the bottom side of the half substrate is set. A 0.6 mm thick dummy half-board is glued with UV-curing resin to give a total thickness of 1.2
The disk 100 may be mm.

On the other hand, when the disc 100 of FIG. 1 is a double-sided disc, the thickness of the half substrate from the lower side surface of the substrate 104 to the upper side surface of the protective layer 101 is the same as that of the half substrate before bonding of the current DVD disc. It is set to about 6 mm, and these half-boards are bonded to each other on the lower bottom surfaces of the board 104 by an ultraviolet curable resin or the like. The thickness of the bonded substrate after adhesion is about 1.2 mm as in the current DVD disc.

FIG. 1 exemplifies the case of a single-sided disc 100 having three layers on one side. This disk 100 is a ROM / RA
In the case of the M hybrid disc, the recording layers 111 to 11
One or two of the three are ROM layers (a metal reflective film is deposited on pits formed by physical unevenness). For example, the first recording layer 111 is a semitransparent layer of a gold thin film, and the second and third recording layers are phase change recording layers. The following description will be continued on the assumption that all of the recording layers 111 to 113 are phase change recording layers.

Numerical aperture N is used for writing (recording) and reading (reproducing) information on the recording layers 111 to 113 in FIG.
A is performed via the optical head 200 having a high NA objective lens 220a with A of about 0.8 to 0.9.

In the single-sided, three-layer disc 100 shown in FIG.
The recording layer 111 to the third recording layer 113 are combined to form one volume space. Of the volume space, the side with the smallest logical sector number (lead-in side)
Is provided with a management information area, and subsequently a user area divided into a plurality of zones (for example, zone 0 to zone 34) is provided. The user area is assigned to a plurality of logical sectors that make up the volume space.
Although not shown, another management information area may be further provided on the side with the larger logical sector number (readout side).

The management information area is an unused space descriptor "Unallocated Spac" as management information used in the present invention.
e Descriptor (USD for short) ”and other management information. According to the description content of this USD, what part of the volume space (which physical sector of which recording layer) is recorded and where it is unrecorded. Or where it is in the erased / deleted state.

In the single-sided three-layer disc 100 shown in FIG.
Consider a case where the laser beam is recording on the second recording layer 112. In this case, when the recorded area and the unrecorded area are mixed in the first recording layer 111 and the third recording layer 113, the mixed state has the following effects: (1) First recording The transmittance of the layer 111 varies (between the recorded area and the unrecorded area), and the intensity of the light spot formed on the second recording layer 112 is not stable; (2) the reflection of the first recording layer 111 The rate changes (between the recorded area and the unrecorded area), and the amount of reflected light from the first recording layer 111 changes; (3) the reflectance of the third recording layer 113 (the recorded area and the unrecorded area) The amount of light that passes through the second recording layer 112 and is reflected by the third recording layer 113.

The above influences (1) to (3) are that the recording is not performed on the other layers until all the recording layers are in the recording state (crystallized / crystallized state in the phase change recording layer). Management (eg step ST24 YES, ST26, S in FIG. 3)
T28 is a system control unit (for example, M in 210 of FIG. 2).
This can be avoided by the PU). That is, when recording on the second recording layer 112 starts, the first recording layer 111
Is already crystallized / crystallized,
Similarly, when recording on the third recording layer 113 starts,
The entire recording layer 112 is already crystallized / crystallized, and at the start of recording on another layer, a state in which a recorded area and an unrecorded area are mixed is removed. For this reason, the above influences (1) to (3) due to the "state where the recorded area and the unrecorded area are mixed"
Can be avoided.

FIG. 2 is a block diagram for explaining the structure of the information recording apparatus (recording / reproducing apparatus) according to the embodiment of the present invention. An optical disc 100 having a configuration as shown in FIG.
Is mounted on the turntable of the spindle motor 200 and driven to rotate. The rotation speed (rotation frequency) of the spindle motor 200 is detected by the pulse generator 202, and the detection result is notified to the system control unit 210. The system control unit 210 includes an MPU that executes various control programs, a ROM in which various control programs, fonts, and other data are written, a RAM used as a work area, and the like. The system control unit 210 gives a rotation command to the motor driver 204 according to the notified rotation speed information. Motor driver 20
Reference numeral 4 drives the spindle motor 200 based on a rotation command from the system controller 210 so that the optical disc 100 rotates at a constant linear velocity (CLV) or at a constant angular velocity (ZCAV) for each zone. .

The optical disk 10 which is rotationally driven in this way
Recording or reproduction on any of the 0 recording layers 111 to 113 is performed via the optical head 220. That is, when the start / end position of recording or reproduction is specified,
The physical sector corresponding to the start position is the system control unit 210.
Of the optical head driver 22 so that the spot of the laser beam is located at the calculated physical sector position (recording layer and track position corresponding to that position)
Command is sent to 2. After the laser beam spot is focused on the recording layer including the calculated physical sector and is tracking on the track corresponding to the sector position, the encoded signal sent from the encoder (MPEG2 encoder, etc.) 30 is transmitted. Recording data is recorded from the sector at the recording start position. By this recording process, the recorded portion on the corresponding phase change recording layer (for example, the second recording layer 112 in FIG. 1) of the optical disc 100 is crystallized / crystallized.

In the reproducing process, the laser reflected light that changes according to the phase change state on the recording layer to be read (for example, the second recording layer 112 in FIG. 1) of the optical disc 100 is emitted from the optical head 22.
0 is detected, and read information corresponding to the detected reflected light is decoded by a decoder (MPEG2 decoder etc.) 232 to obtain reproduced data.

FIG. 3 is a flow chart for explaining the information recording method according to the embodiment of the present invention. The process of this flowchart can be executed by the MPU in the system control unit 210 of FIG.

First, a recording layer for starting recording (eg, FIG.
Second recording layer 112) is designated (step ST1).
0). For this designation, the head sector position of the unrecorded area of the optical disc 100 is obtained from the management information USD in the management information area of FIG. 1, and then the MPU of the control unit 210 designates the recording layer including this sector position.

Next, the designated recording layer (second recording layer 11
It is checked whether there is a vacancy in 2) (step S).
T12). This check can be performed by observing the difference between the head sector position of the unrecorded area obtained from the management information USD and the logical sector number at the end of the designated recording layer (second recording layer 112). When the designated recording layer (second recording layer 112) has a free space (step ST1)
2) and the recording process (step ST20).

If the designated recording layer (second recording layer 112) has no free space (NO in step ST12), another recording layer (first recording layer 111 and / or third recording layer 11)
It is checked whether there is a vacancy in 3) (step ST1)
4). When there is no free space in the other recording layer (step ST1
No, recording is not performed, and the process of FIG. 3 ends (step ST16). Another recording layer (for example, the third recording layer 11
If there is a vacancy in 3) (Yes in step ST14),
The designated recording layer is switched to another recording layer (here, the second recording layer
(The recording layer 112 is switched to the third recording layer 113)
(Step ST18), recording process (step ST20)
Move to.

The designated recording layer (here, the second recording layer 1
If the recording using 12 is completed (step ST
22), the management information USD is rewritten to the content indicating the recording end position (step ST30), and the processing of FIG. 3 ends.

The designated recording layer (here, the second recording layer 1
While recording using 12) is continued (NO in step ST22), the processes of steps ST20 to ST24 are repeated until the entire writing of the designated recording layer (second recording layer 112) is completed. Specified recording layer (second recording layer 11
When the whole surface writing of 2) is completed (Yes in step ST24), it is checked whether or not to continue recording in another recording layer (here, the third recording layer 113) (step ST2).
6). According to the contents of the management information USD, the sector in the unrecorded state (or erased / deleted state) is in another recording layer (third recording layer
If the data remains in 13), recording can be continued in another recording layer (YES in step ST26). in this case,
First, the designated recording layer is switched (here, the second recording layer 1
12 is switched to the third recording layer 113) (step ST28), and the process returns to step ST12.

The above processing (steps ST12 to ST2)
According to 8), all the information to be recorded is the optical disc 1.
If the recording area of 00 (here, the second recording area 112 and the third recording area 113) has been completely recorded, or if the free area of the optical disc 100 has been used up without recording, the recording process ends ( At step ST22, the management information USD is rewritten to the content indicating the recording end position (step ST30), and the process of FIG. 3 ends.

In the recording process of FIG. 3, after a specific recording layer (for example, the second recording area 112) is completely recorded (YES in step ST24), another recording layer (for example, the third recording area 113) is recorded. A major feature is that the recording is performed (YES in steps ST26, ST28, and ST20).

FIG. 4 is a flow chart for explaining an information recording method according to another embodiment of the present invention. The process of this flowchart can be executed by the MPU in the system control unit 210 of FIG. Processing step ST4 in FIG.
0 to 48 are processing steps ST10 to ST10 of FIG. 3, respectively.
Since it corresponds to 18, the description of the contents is omitted.

Designated recording layer (eg, second recording area 112)
If there is a free space (YES in step ST42), the size of the recording data to be recorded from now on is compared with the free space of the corresponding recording layer (here, the second recording area 112) (step ST50). The free space of the corresponding recording layer is smaller than the recording data size (No in step ST50),
If there is no other recording layer having a free space larger than the recording data size (NO in step ST52), recording is not performed and the process of FIG. 4 ends (step ST46).

When there is another recording layer (for example, the third recording area 113) having a free space larger than the recording data size (YES in step ST52), the empty area of the corresponding recording layer (second recording area 112) is the temporary data. After being overwritten with dummy data of all “0” or all “1” (or after being overwritten with temporary data), the recording layer is switched to another recording layer (third recording area 113) (step S
(T54), the process returns to step ST42.

On the other hand, the corresponding recording layer (currently designated recording layer 11
When the free space in 2) is equal to or larger than the recording data size (YES in step ST50), recording processing (step ST6) is performed.
Enter 0). Hereinafter, steps ST60 to ST70 of FIG.
Correspond to the processing steps ST20 to ST30 of FIG. 3, respectively, and the description thereof will be omitted.

In the recording process of FIG. 4, when recording is performed on the rewritable recording layer (112), the rewritable recording layer (112) is not erased (amorphized) so that no region remains. All the recording areas are set to the written state (YES in step ST54 or STST64). This is one of the features of the processing of FIG.

In the recording process of FIG. 4, although the amount of data to be recorded is larger than the size of the unrecorded area of the one recording layer (for example, 112) to be recorded (step ST50: No), recording is performed. The other recording layer having an unrecorded area larger than the size of the power data (for example, 11
3) is present (Yes in step ST52), after the unrecorded area of the one recording layer (for example, 112) is overwritten with temporary data (dummy data) (step ST5).
4) Write all the data to be recorded in the unrecorded area of the other recording layer (for example, 113) (step S
T60 to ST64). Here is another feature of the process of FIG.

Due to the above characteristics, for example, when recording on the lower recording layer 113 in FIG. 1 is started, all of the upper recording layer 112 is in the written state (the crystallization / crystallization state in the phase change recording layer). Therefore, the upper recording layer 112 is not in a state where crystallized portions and amorphized portions are mixed. Therefore, the recording on the lower recording layer 113 can be performed stably and satisfactorily.

FIG. 5 is a flow chart for explaining the information erasing method according to the embodiment of the present invention. The process of this flowchart can be executed by the MPU in the system control unit 210 of FIG.

When a part or all of the information already recorded on the optical disc 100 shown in FIG. 1 is to be erased (YES in step ST80), first, a portion to be erased is designated. When the user makes this designation, it can be designated by time, such as "30th to 60th minutes from the start of recording". When the time is thus designated, the MPU of the control unit 210 in FIG. 2 converts the designated time into the corresponding logical sector number (step ST82).

Next, the designated location (converted logical sector number LSN _{i to} LSN _j ) is overwritten with temporary data (dummy data of all "0" or all "1", etc.) and the location is erased. Instead of the "amorphous" state, the "crystalline / crystallized" state is written with meaningless data. Then, the management information USD of the designated place is changed to the state where the information of the place is erased (step ST84).

In the recording process of FIG. 5, when the writing contents of the recorded area of the phase change recording layer (for example, the second recording layer 112) are erased (YES in step ST80), the temporary data (dummy data) is recorded in this recorded area. 2) is overwritten and the recorded area is erased in the crystallized / crystallized state (step ST84).

FIG. 6 is a flow chart for explaining the information deletion (temporary deletion) method according to the embodiment of the present invention. The process of this flowchart can be executed by the MPU in the system control unit 210 of FIG.

When a part or all of the information already recorded on the optical disc 100 shown in FIG. 1 is to be deleted (or temporarily erased) (YES in step ST90), first, the part to be deleted is designated. When the user makes this designation, it can be designated by time, such as "30th to 60th minutes from the start of recording". When the time is designated in this way, the MPU of the control unit 210 in FIG. 2 converts the designated time into the corresponding logical sector number (step ST
92).

Next, the write state (crystallized / crystallized state) of the designated portion (converted logical sector numbers LSN _{m to} LSN _n ) is maintained as it is, and the management information USD of the designated portion is maintained. Is changed to a state in which the information at that location has been deleted (or temporarily erased) (step ST9
4). This is similar to discarding unnecessary files in the trash can icon in the personal computer graphical user interface. Between the processing of FIG. 6 and the trash can icon processing of the personal computer,
There is a big difference in that the data to be left without being erased is set in a written state (crystallized / crystallized state), that is, the crystallized state and the amorphized state are not mixed.

That is, in the recording process of FIG. 5, when a part or all of the data of the content information already recorded is deleted (YES in step ST90), the data to be deleted is left without being deleted. A major feature is that the data related to data to be deleted (USD) of the management information is changed to apparently put the data to be deleted into the erased state (step ST94).

The present invention is not limited to the above embodiments, and various modifications and changes can be made at the stage of carrying out the invention without departing from the spirit of the invention. Also,
The respective embodiments may be combined as appropriate as much as possible, and in that case, the effect of the combination can be obtained.

Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of constituent elements disclosed in this application. For example, even if one or more constituent elements are deleted from all the constituent elements shown in the embodiment, if at least one of the effect of the present invention or the effect of implementing the present invention is obtained, the constituent element is The deleted configuration can be extracted as an invention.

[0049]

As described above, according to the information recording method of the present invention, an optical medium having a high NA objective lens is used to form an information medium having a multilayer recording layer (for example, a thin protective layer is provided and an interlayer distance is reduced). Good recording can be performed on a small single-sided multilayer optical disc).

[Brief description of drawings]

FIG. 1 is a diagram for explaining the structure of an information medium (optical disk having a single-sided three-layer structure) having a multilayer recording layer according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an information recording device (recording / reproducing device) according to an embodiment of the present invention.

FIG. 3 is a flowchart explaining an information recording method according to an embodiment of the present invention.

FIG. 4 is a flowchart explaining an information recording method according to another embodiment of the present invention.

FIG. 5 is a flowchart explaining an information erasing method according to an embodiment of the present invention.

FIG. 6 is a flowchart showing an information deleting (temporary deleting) method according to an embodiment of the present invention.

[Explanation of symbols]

100 ... Single-sided multi-layer recordable information medium (for example, single-sided 3-layer phase change recording type optical disc); 101 ... Protective layer (thickness 1
00, about 100 μm); 102, 103 ... Intermediate layer (space layer); 104 ... Substrate; 111 ... First recording layer (phase change recording layer or semitransparent metal layer); 112 ... Second recording layer (phase change recording layer or semitransparent layer) Transparent metal layer); 113 ... Third recording layer (phase change recording layer or semi-transparent metal layer); 210 ... System control unit (including MPU / ROM / RAM); 220
... optical head (optical system); 220a ... objective lens (aperture ratio NA is about 0.8 to 0.9); 200 to 204 ... rotary drive system; 230 ... recording system encoder; 232 ... reproducing system decoder.

Claims (6)

[Claims] 1. An information medium having two or more multi-layer recording layers as a recording target, wherein information is recorded on the multi-layer recording layers by a light beam, when recording, all the specific recording layers are recorded. An information recording method characterized in that it is configured to perform recording on another recording layer after the recorded state. 2. The multi-layer recording layer includes a rewritable recording layer in which information writing and erasing can be repeatedly performed, and when recording is performed on the rewritable recording layer, the rewritable recording layer does not leave an erased area. 2. The method according to claim 1, wherein the recording area of the recording layer is configured to be entirely written. 3. The other recording layer in which the data to be recorded is larger than the size of the unrecorded area of one recording layer to be recorded, but has the unrecorded area larger than the size of the data to be recorded. If there is, the unrecorded area of the one recording layer is written with temporary data, and then all the data to be recorded is written in the unrecorded area of the other recording layer. The method according to claim 1 or 2, wherein 4. The multi-layer recording layer has at least one phase change recording layer, and when erasing the written contents of the recorded area of the phase change recording layer, the recorded area is overwritten with temporary data, 4. The method according to claim 1, wherein the recorded area is configured to be erased in a crystallized state. 5. The multi-layer recording layer is configured to record content information and management information for managing a writing state of the content information, and a part or all of the content information already recorded. When data is deleted, the data to be deleted is left unerased, and the portion of the management information related to the data to be deleted is changed to apparently erase the data to be deleted. The method according to any one of claims 1 to 4, wherein the method is configured to: 6. The information medium is an optical disc, and a drive system for rotationally driving the optical disc and an optical for optically recording or reproducing information on a recording layer of the rotationally driven optical disc. And a system.
An optical disc apparatus, which is configured to perform the method according to claim 5.