JP3832889B2 - Multi-layer disc - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is related to a multi-layer disk, in particular, the recording layer data tracks for recording data are spirally are arranged a plurality of layers, multilayered scheme reading head for reading data, one from one side of the disk about the disk.
[0002]
[Prior art]
Conventional recording media include acoustic compact cassettes using magnetic tape, video cassettes for video recording, and the like. However, the data recorded on these recording media cannot be randomly accessed, and since the recorded data was analog information, the playback data contained noise, the data deteriorated when copied, There was a problem that data deteriorated after long-term storage.
[0003]
Therefore, as a recording medium, an optical disc that can convert data into a digital signal and record it on a data track on the disc, irradiate the data track with a laser beam, and perform reading using the return light Has been put to practical use. In this optical disc, data is recorded by forming concave or convex portions called pits in a row on the data track of the optical disc, the presence or absence of pits is made to correspond to “1” or “0” of the data, and the laser beam Is read out using the reflected light and is read-only. Typical examples of such an optical disk include a CD (compact disk) for music and an LD (laser disk) for video, and a small DVD (digital video / video) for video. Disc) is also under development. In such CDs, LDs for long-time recording, and DVDs, data is continuously recorded spirally from the inner periphery to the outer periphery of the disc, and the linear velocity at the time of data reading is constant (CLV). is there.
[0004]
In recent years, magneto-optical disks capable of recording data on a recording medium with a laser beam and magnetism and reading the data using the laser beam have been put into practical use. As typical examples of such a magneto-optical disk, an MD (mini disk) and a magneto-optical disk used for an external memory of a computer are known. MD is also CLV, and data is continuously recorded spirally from the inner periphery to the outer periphery.
[0005]
On the other hand, since an optical disc such as a CD is designed to record data only on one side, in order to increase the recording capacity, in addition to increasing the recording density of the recording medium on the disc, the recording layer on the disc is made multilayer. There is a way. As the multi-layer disc, a DVD double-layer type or the like can be considered, but in the future, a multi-layer disc having three or more layers is also possible.
[0006]
Incidentally, the types of data recorded on the optical disc can be roughly divided into the following three types.
(1) Completely continuous data such as music and movies (2) Data that is not continuous at all, such as a dictionary (3) Data that has a predetermined unit of continuity, such as a map or a game When data is recorded on the aforementioned multilayer disk and read from one side of the disk using one head, in the case of (1) data, the data is recorded from the innermost to the outermost part of each recording layer. If the data is recorded, the data is continuous except for the boundary between the recording layers. Therefore, the head can read the data smoothly except that the head moves greatly at the boundary. In the case of the data (2), the data designated for search is not continuous, and the head moves to a predetermined part of each recording layer in accordance with the data designated for search. As in the case of the data (1), there is no problem even if the data is recorded from the innermost periphery to the outermost periphery of each recording layer.
[0007]
[Problems to be solved by the invention]
However, in the case of data having a predetermined unit of continuity such as a map or a game, if a predetermined unit of data is recorded in order from the innermost part to the outermost part of each recording layer, the search is designated. Depending on the order of data, the amount of head movement is large, or there is a high probability that the head will reciprocate between the innermost and outermost parts of the disk many times. The cost of the device may increase.
[0008]
This problem will be described by taking as an example the case where the predetermined unit of data shown in FIG. 9A is a map unit that can be displayed on the screen of the display device.
As shown in FIG. 9 (a), it is assumed that a map M of a predetermined area is divided into nine data units due to the restriction on the size of the screen of the display device on which the map M is displayed. Then, the recording order of the data units {circle around (1)} to {9} of the divided areas m1 to m9 is in the order of the numbers {circle around (1)} to {9}. Suppose that it is as shown in FIG. Now, the map searcher is displaying a map of the area m5 (data unit number {circle over (5)}) on the screen. Next, the map of the area m9 (data unit number {circle over (9)}) adjacent to the map of the area m5 is displayed. When displaying on the screen, the moving distance of the head 5 becomes four data units from the inner circumference side to the outer circumference side of the disk as shown in FIG. 9B, and the access time becomes longer. It was.
[0009]
In view of this, the present invention records data having a predetermined unit of continuity such as a map or a game on a multi-layer disk and reads it from one side of the disk with a single head. By devising the recording order of the data unit, the head access time can be shortened, and the head access time can be shortened even when searching for data that is not continuous at all like a dictionary an object of the present invention is to provide a disk.
[0010]
[Means for Solving the Problems]
According to the present invention for achieving the above object , a disk is provided with a plurality of recording layers, the data track of each recording layer is formed in a spiral shape, and data is read from only one side of the disk by one data reading head. A dedicated multi-layer disc, in which the total data recorded on the multi-layer disc is divided into units that do not differ greatly in the amount of data in the radial direction of the recording layer, and the divided data unit is the first recording layer To the final recording layer in order, and subsequent data units are recorded in reverse order from the final recording layer to the first recording layer, and this recording order is repeated thereafter. According to regularity, the data unit is distributed and recorded on each recording layer.
When the data amount of each data unit is not uniform, the data unit is dispersed and recorded on each recording layer by the regularity that the data unit having a small data amount is continuously recorded on the same recording layer .
[0011]
Further, the present invention for achieving the above object is a system in which a disk is provided with a plurality of recording layers, data tracks of each recording layer are formed in a spiral shape, and data is read from only one side of the disk by one data reading head. Read-only multi-layer discs, and the total data to be recorded on the multi-layer disc is divided into a unit of data as a data unit, and the divided data units are sequentially arranged from the first recording layer. The recording layer is recorded up to the final recording layer, and the subsequent data unit is recorded again from the first recording layer in order to the final recording layer. data unit is distributed is recorded into each recording layer, when the data amount is uniform for each data unit, the recording of the data unit by one data unit in the same recording layer The regularity of that, the data unit is distributed is recorded into each recording layer, when the data amount of each data unit is not uniform, small data units of the data amount consecutively in the same recording layer recording Due to the regularity, the data unit is distributed and recorded on each recording layer.
[0012]
According to the multilayer disk of the present invention, when data that is continuous within a predetermined data unit is recorded on the multilayer disk and read from one side of the disk by one head, the predetermined data unit is moved up and down. Since the recording is performed by being distributed to the adjacent recording layers, the amount of movement of the head for reading data can be reduced as compared with the case where a predetermined data unit is continuously recorded on one recording layer. Access time is reduced .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail together with specific examples with reference to the accompanying drawings. The multi-layer disc targeted by the present invention is a read-only multi-layer disc in which data tracks for recording data are spirally formed.
As shown in FIG. 1, a multi-layer disc has a plurality of disc-like recording layers in which data tracks for recording data are formed in a spiral shape, for example, a first recording layer 1 and a second recording layer 2. , And the third recording layer 3 is a multi-layer disc 10 configured by arranging three layers. There is one head 5 for reading data, and this is a method of reading data from only one side of the multilayer disk 10. In the present invention, the total data to be recorded on the multi-layer disc 10 is divided into predetermined units, and the divided data units are distributed and recorded on each disc-shaped recording layer with predetermined regularity. It is.
[0014]
FIG. 2 (a) shows an embodiment of the total data to be recorded on the multilayer disk. And this total data shall be comprised by the data unit AZ which can be divided | segmented for every predetermined unit, for example.
FIG. 2B is an explanatory diagram showing an embodiment of a writing method in the case where the total data composed of data units A to Z as shown in FIG. is there. In this embodiment, the first data unit A of the data units A to Z divided by a predetermined unit is first recorded in the recording area of the innermost peripheral portion of the first recording layer 1 from the inner peripheral side to the outer peripheral side. To do. The subsequent second data unit B is recorded from the inner circumference side toward the outer circumference side in the innermost circumference recording area of the second recording layer 2, and the third data unit C is again the first recording layer. Recording is performed from the inner circumference side toward the outer circumference side in a recording area adjacent to the recording area in which one data unit A is recorded. Thereafter, similarly, the remaining data units D to Z are sequentially recorded on the first recording layer 1 and the second recording layer 2 from the inner periphery side.
[0015]
FIG. 2 (c) is an explanatory diagram showing the reproduction order when the head 5 continuously reads data from the two-layer disk 20 on which data units A to Z are recorded as shown in FIG. 2 (b). Although a gap is drawn between adjacent data units in FIG. 2 (c), there is actually no gap, and the adjacent data units are continuously recorded in the first recording layer 1 or the second recording unit. Recorded on the recording layer 2. When the head 5 reads data continuously, the data unit A is first read from the innermost circumference of the first recording layer 1 of the disk 20, and then the head 5 returns to the innermost circumference of the disk, and the focal length And the data unit B is read from the innermost peripheral portion of the second recording layer 2. After reading the data unit B, the head 5 can read the data unit C of the first recording layer 1 by changing its focal length without moving.
[0016]
In FIG. 2 (c), in order to explain the arrangement of the data unit, the case where the head 5 continuously reads out the data unit recorded on the two-layer disc has been described. In the case of data having unit continuity, there is little possibility that the head 5 reads all data units continuously.
FIG. 3A is an explanatory diagram showing another embodiment of the writing method in the case where the total data composed of the data units A to Z as shown in FIG. It is. In this embodiment, the first data unit A of the data units A to Z divided by a predetermined unit is first recorded in the recording area of the innermost peripheral portion of the first recording layer 1 from the inner peripheral side to the outer peripheral side. To do. The subsequent second data unit B is recorded in the innermost peripheral recording area of the second recording layer 2 from the inner peripheral side to the outer peripheral side, and the third data unit C is the second recording layer 2. In the recording area adjacent to the recording area of the innermost peripheral portion, the recording is performed from the inner peripheral side to the outer peripheral side, and the fourth data unit D is a recording area in which the data unit A of the first recording layer 1 is recorded again. Is recorded from the inner circumference side toward the outer circumference side. Thereafter, similarly, the remaining data units E to Z are sequentially recorded on the first recording layer 1 and the second recording layer 2 from the inner circumference side by two data units.
[0017]
FIG. 3 (b) shows the reproduction order when the head 5 continuously reads data from the two-layer disk 20 on which the data units A to Z are recorded as shown in FIG. 3 (a). It is explanatory drawing similar to FIG. When the head 5 reads data continuously, the data unit A is first read from the innermost circumference of the first recording layer 1 of the disk 20, and then the head 5 returns to the innermost circumference of the disk, and the focal length And the data unit B is read from the innermost peripheral portion of the second recording layer 2. After reading the data unit B, the head 5 subsequently reads the data unit C from the data recording area adjacent to the innermost periphery of the second recording layer 2. Thereafter, the head 5 moves to the data recording area adjacent to the innermost peripheral portion of the first recording layer 1, and reads the data unit D of the first recording layer 1 by changing the focal distance. repeat.
[0018]
FIG. 4 (a), the total data consisting of data units A~Z as shown in FIG. 2 (a), an explanatory view showing an embodiment of a write method for writing a three-layer disk 30 is there. In this embodiment, the first data unit A of the data units A to Z divided by a predetermined unit is first recorded in the recording area of the innermost peripheral portion of the first recording layer 1 from the inner peripheral side to the outer peripheral side. To do. The subsequent second data unit B is recorded in the innermost recording area of the second recording layer 2 from the inner circumference side to the outer circumference side, and the third data unit C is the third recording layer 3. In the innermost peripheral recording area, recording is performed from the inner peripheral side toward the outer peripheral side. The fourth data unit D is recorded again from the inner circumference side to the outer circumference side in the recording area adjacent to the recording area in which the data unit A of the first recording layer 1 is recorded. Thereafter, similarly, the remaining data units E to Z are repeatedly recorded in order from the first recording layer 1 toward the third recording layer 3 from the inner periphery side to the outer periphery side.
[0019]
FIG. 4B is an explanatory diagram showing the reproduction order when the head 5 continuously reads data from the three-layer disk 30 on which data units A to Z are recorded as shown in FIG. In FIG. 4B, there is actually no gap drawn between adjacent data units, and adjacent data units are recorded continuously.
When the head 5 reads data continuously, the data unit A is first read from the innermost periphery of the first recording layer 1 of the three-layer disc 30, and then the head 5 returns to the innermost periphery of the disc. The data unit B is read from the innermost circumference of the second recording layer 2 while changing the focal length, and the head 5 returns to the innermost circumference of the disk, and the focal length is changed to change the third recording layer 3. Data unit C is read from the innermost periphery. After reading the data unit C, the head 5 can read the data unit D of the first recording layer 1 by changing its focal length without moving. The head 5 repeats reading as described above.
[0020]
FIG. 5A is an explanatory diagram showing another embodiment of a writing method in the case where the total data composed of the data units A to Z as shown in FIG. It is. In this embodiment, the first three data units A, B, and C of the data units A to Z divided by a predetermined unit are divided into the first recording layer 1, the second recording layer 2, and the third recording unit, respectively. Recording is performed in the recording area of the innermost peripheral portion of the recording layer 3 from the inner peripheral side toward the outer peripheral side. On the contrary, the fourth to sixth data units D, E, and F are recorded on the innermost circumference of the third recording layer 3, the second recording layer 2, and the first recording layer 1, respectively. Recording is performed from the inner circumference side toward the outer circumference side in a recording area adjacent to the area. Thereafter, similarly, the remaining data units G to Z are sequentially arranged in the direction from the first recording layer 1 to the third recording layer 3 and from the third recording layer 3 to the first recording layer 1. Recording is performed from the inner circumference side toward the outer circumference side by one data unit while repeating the recording in the direction.
[0021]
FIG. 5 (b) shows the reproduction order when the head 5 continuously reads data from the three-layer disk 30 on which data units A to Z are recorded as shown in FIG. 5 (a). It is explanatory drawing similar to FIG. When the head 5 reads data continuously, first, similarly to the reproduction order of FIG. 4 (b), respectively, from the first recording layer 1 to the third recording layer 3 of the three-layer disc 30, respectively. The data units A, B, and C are sequentially read from the innermost peripheral portion of the optical disc while changing the focal length. Next, the head 5 moves from the third recording layer 3 of the three-layer disk 30 to the first recording layer 1 and from the recording area adjacent to the innermost peripheral portion to the data units D, E, and F is sequentially read while changing the focal length. The head 5 repeats reading as described above.
[0022]
Here, the total data described in FIG. 2 (a) is the map M of the predetermined area described in FIG. 9 (a), and the map M is divided into nine areas m1 to m9. When recording the data units {circle around (1)} to {circle around (9)} of the respective areas m1 to m9 on the two-layer disc 20 of the present invention, the recording method described with reference to FIG. 2 (b) and FIG. Data reading from the double-layer disk 20 of the present invention of the head 5 will be described.
[0023]
According to the recording method described with reference to FIG. 2 (b), the data units {circle around (1)} to {9} of the divided areas m1 to m9 are recorded on the two-layer disc 20 as shown in FIG. 6 (a). Is done. Further, according to the recording method described with reference to FIG. 3A, the data units {circle around (1)} to {9} of the divided areas m1 to m9 are shown on the two-layer disc 20 as shown in FIG. 6 (b). To be recorded.
Now, the map searcher is displaying the map of the area m5 (data unit number ▲ 5 ▼) in FIG. 9A on the screen, and then the area m9 (data unit number ▲) adjacent to the map of the area m5. Let us consider a case where the map 9) is to be displayed on the screen. In this case, the movement distance of the head 5 is the same regardless of whether the data units (1) to (9) are recorded as shown in FIG. 6 (a) or as shown in FIG. 6 (b). There are two data units from the inner circumference side to the outer circumference side of the disk. In the conventional recording method described with reference to FIG. 9B, the moving distance of the head 5 is four data units. Therefore, the access time of the head is shorter in the dual-layer disk 20 of the present invention. Yes.
[0024]
Therefore, the map searcher displays the map of the area m5 (data unit number 5) in FIG. 9A on the screen, and then the area m1 (data unit number ▲) adjacent to the map of the area m5. 1)) to the area m9 (data unit number {circle around (9)}), the moving distance of the head 5, that is, the number of areas to which the head 5 moves is set as the double-layer disk 20 of the present invention. FIG. 7 shows a comparison between this case and the conventional apparatus (data recorded only on the recording area of one layer of a one-layer disc or two-layer disc). As can be seen from FIG. 7, the average value of the moving distance of the head 5 in the two-layer disk 20 of the present invention is about half that of the conventional apparatus, and data is stored as in the two-layer disk 20 of the present invention. The head access time is shorter when recording.
[0025]
If the three-layer disk 30 as described in FIG. 4 or FIG. 5 is used and all the three data recording layers are used to record the map data of FIG. Becomes even shorter.
In the embodiment described above, the total data can be divided into approximately the same amount. Next, an example in which the amount of data at each segment is not uniform when the total data is segmented in a predetermined state will be described.
[0026]
FIG. 8A shows an example in which the total amount of data is divided at predetermined data delimiters and the amount of data at each delimiter is not uniform. In such a case, according to the present invention, when the data to be recorded on the data track on each recording layer of the multi-layer disc is recorded from the inner side of the disc, the amount of data from the inner side of the disc is substantially the same. Distribute each delimiter data. In this case, in this embodiment, delimiter data having a small data amount is continuously recorded on the data track of the same layer so that the data amount of each recording layer is substantially the same.
[0027]
FIG. 8B shows the first recording of the two-layer disc 20 in such a manner that the total data of FIG. This is an example in which the data of each segment is distributed and arranged so that the data amount from the inner circumference side of the layer 1 and the data amount from the inner circumference side of the second recording layer 2 are substantially the same. is there. In this way, when recording is performed so that the data amount of each recording layer of the multi-layer disk is substantially the same, the head access is performed when searching for data in which the data is partially continuous, such as a map divided by regions. Time can be improved.
[0028]
In the embodiment described above, the division of the total data is performed by dividing the data. However, the predetermined unit for dividing the total data may be a sector unit.
Since the above-mentioned DVD has a constant linear velocity (CLV), it takes time to access. In the case of a 12 cm disk, the head access time from the outermost circumference to the innermost circumference is about 120 to 250 ms. On the other hand, when the multilayer disk of the present invention described above is adopted for a DVD, the movement of the head is minimal, and when changing the recording layer up and down, it is only necessary to change the focal length of the light emitted from the head. Therefore, access is possible in a few ms, and when the data is continuously recorded on the first recording layer and the second recording layer from the inner peripheral side, the first recording layer and the second recording layer The head access time can be reduced to about 1/30 to 1/80 as compared with the case where the head reciprocates between the outermost circumference and the innermost circumference at the boundary portion.
[0029]
In addition, since the change in the recording layer of the head in the present invention depends on the head side, the same effect can be obtained even on an inexpensive one that does not use a high torque motor on the disk drive side.
Further, in addition to recording data having a predetermined unit of continuity such as a map or a game as described above, data having no continuity such as a dictionary may be recorded on the multilayer disc of the present invention. Since the data is equally arranged in each recording layer, the maximum moving distance of the head can be shortened, and the access time of the head can be shortened to about 1 / (number of recording layers).
[0030]
【The invention's effect】
According to the present invention described above, in the multi-layer disc, maps, games, or as in the dictionaries, one read f Record the data that the continuity of the predetermined unit in the multilayer disc Tsu when reading from one side of the disc in de, by recording data on a recording layer adjacent the total data in the vertical dispersed in predetermined units, it is possible to reduce the maximum travel distance of the read f head reads f There is an effect that the access time of the mobile phone can be shortened.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the principle configuration of a multilayer disk of the present invention.
FIG. 2A is a diagram showing total data that can be divided into multi-layer discs according to the present invention, and FIG. 2B is a diagram in the case where a divided data unit of total data in FIG. FIG. 4C is an explanatory diagram showing an example of a writing method, and FIG. 4C is an explanatory diagram showing a reproduction order when the head continuously reads data from a two-layer disk on which data units are recorded as shown in FIG.
3A is an explanatory diagram showing another example of a writing method when the divided data unit of the total data of FIG. 2A is written on a two-layer disk, and FIG. 3B is a diagram of FIG. It is explanatory drawing which shows the reproduction | regeneration order in case a head reads data continuously from the double layer type disk in which the data unit was recorded in this way.
4A is an explanatory diagram showing an example of a writing method in the case where the divided data unit of the total data of FIG. 2A is written on a three-layer disc, and FIG. 4B is an explanatory diagram as shown in FIG. It is explanatory drawing which shows the reproduction | regeneration order in case a head reads data continuously from the 3 layer type disc in which the data unit was recorded.
5A is an explanatory diagram showing another example of a writing method in the case where the divided data unit of the total data of FIG. 2A is written on a three-layer disc, and FIG. 5B is a diagram of FIG. It is explanatory drawing which shows the reproduction | regeneration order in case a head reads data continuously from the three-layer type disk in which the data unit was recorded in this way.
6A is an explanatory diagram for explaining data arrangement when data of each area of the map shown in FIG. 9 is recorded on a two-layer disc by the method of FIG. 2B, and FIG. 9 is an explanatory diagram for explaining a data arrangement when data of each area of the map shown in FIG. 9 is recorded on a two-layer disc by the method of FIG.
FIG. 7 is a comparative view showing a comparison of head movement distances of the present invention and a conventional apparatus when displaying each area surrounding the area in the center of the map shown in FIG. 9;
FIG. 8A is an explanatory diagram showing the structure of total data in which the amount of data at each segment is not uniform, and FIG. 8B is a diagram showing the total data of (a) from the inner circumference side to each recording layer of a dual-layer disc. It is explanatory drawing which shows the example arrange | positioned so that data amount may become uniform in each recording layer.
FIG. 9A is an explanatory diagram showing a map M of a predetermined region divided into nine regions due to restrictions on the screen size of the display device, and FIG. 9B is a data unit indicating each region of FIG. FIG. 2 is a diagram for explaining a conventional disc recording method in which a disc is continuously recorded from the inner circumference side to the outer circumference side of a recording layer of the disc.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 1st recording layer 2 ... 2nd recording layer 3 ... 3rd recording layer 5 ... Head 10 ... Multi-layer disk 20 ... Double-layer disk 30 ... 3-layer disk

Claims (5)

A disk having a plurality of recording layers, a data track of each recording layer is formed in a spiral shape, and a read-only multi-layer disk in which data is read from only one side of the disk by one data reading head,
The total data recorded on this multi-layer disc is divided in units that do not differ greatly in the amount of data in the radial direction of the recording layer,
The divided data units are recorded in order from the first recording layer to the final recording layer,
Subsequent data units are recorded from the last recording layer to the first recording layer in reverse order,
Thereafter, the data unit is distributed and recorded on each recording layer according to the regularity in which the recording order is repeated thereafter. The multi-layer disc according to claim 1, wherein
When the data amount of each data unit is not uniform, the data unit is dispersed and recorded on each recording layer due to the regularity that the data unit having a small data amount is continuously recorded on the same recording layer. Multi-layer disc characterized by being made. A disk having a plurality of recording layers, a data track of each recording layer is formed in a spiral shape, and a read-only multi-layer disk in which data is read from only one side of the disk by one data reading head,
The total data to be recorded on this multi-layer disc is divided in units of data,
The divided data units are recorded in order from the first recording layer to the final recording layer,
Subsequent data units are recorded again from the first recording layer to the last recording layer in order,
Thereafter, the data unit is distributed and recorded in each recording layer by regularity in which this recording order is repeated,
When the data amount of each data unit is uniform, the data units are distributed and recorded on each recording layer due to the regularity that the data units are recorded on the same recording layer one data unit at a time. ,
When the data amount of each data unit is not uniform, the data unit is dispersed and recorded on each recording layer due to the regularity that the data unit having a small data amount is continuously recorded on the same recording layer. Multi-layer disc characterized by being made. The multi-layer disc according to claim 3 ,
In the regularity, when the divided data unit to be recorded on the recording layer on each disk is recorded from the inner circumference side of the disk, a condition for dispersing the data amount from the inner circumference side without much difference is added. Multi-layer disc. The multilayer disk according to any one of claims 1 to 4 ,
The multi-layer disc, wherein the divided data unit is map data divided for each region .

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