JP2991228B2 - Optical disc, optical disc information recording method, and optical disc apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk having at least two layers for recording information. The present invention also relates to a method for recording information on the optical disc. Further, the present invention relates to an optical disk device for reading information from the optical disk.

[0002]

2. Description of the Related Art A layer for recording information on an optical disk has two upper and lower layers.
There is a two-layer optical disk whose recording capacity is doubled by providing layers. Various techniques have been proposed so far to improve the reliability against scratches or dirt on the disc by recording the same information on the double-layer optical disc a plurality of times.

[0003]

The access speed of an optical disk is inferior to that of other recording media in access speed.
On the other hand, the technique of recording the same information on the conventional double-layer optical disc a plurality of times does not lead to overcoming the weakness of the access speed in the optical disc apparatus.

[0004] It is an object of the present invention to provide a multilayer optical disk capable of improving access performance at the time of reading information. Another object of the present invention is to provide an information recording method for obtaining a multi-layer optical disc capable of improving access performance when reading information.

A further object of the present invention is to provide an optical disk apparatus capable of rapidly reading information from a multilayer optical disk.

[0006]

In order to achieve the above object, the present invention provides an optical disc having at least two layers for recording information, wherein the information address in the first information recording layer is smaller on the inner side and smaller on the outer side. Side, the address of the information in the second information recording layer is made smaller on the outer side and larger on the inner side, and the same information is assigned the same address to the first information recording layer and the second information recording layer. It shall be recorded in both.

The present invention also relates to a method for recording information on an optical disk having at least two layers for recording information, wherein the first information recording layer includes an inner peripheral side and an inner peripheral side of the disk. Information is sequentially recorded on the circumferential side, and the same information as the information recorded on the first information recording layer is written on the second information recording layer from the outer periphery of the disk to the opposite side of the first information recording layer. Information is sequentially recorded from the circumferential side or the inner circumferential side to the outer circumferential side.

Further, the present invention relates to an optical disk apparatus for reading information from a multilayer optical disk obtained as described above, comprising: means for obtaining a current position of an optical head; first information recording of information to be read; Means for obtaining a physical position in the layer and a physical position in the second information recording layer;
Means for calculating the distance between the physical position of the information recording layer and the current position of the optical head, the distance between the physical position of the second information recording layer and the current position of the optical head, and the two distances Means for moving the optical head to a physical position having a shorter distance.

[0009] Since the same information is recorded on both the first layer and the second layer on the optical disk, the reliability of the optical disk against scratches and dirt can be improved. Also,
By using the above optical disk device, it is possible to shorten the access time. In an optical disk device, when reading information from a multilayer optical disk,
Information at a physical position close to the optical head is selected and read. Therefore, when reading information, the nearest information is always accessed, and the access time can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1A shows a cross section of the optical disk viewed from the side, and FIG. 1B shows a plan view of the optical disk viewed from below. It should be noted that the figure does not show an actual optical disk at an accurate scale.

The optical disk 1 has two layers of information recording layers 2 and 3 formed vertically. In the following description,
The lower recording layer 2 is called a first layer, and the upper recording layer 3 is called a second layer. The address of the information in the first layer 2 is smaller on the inner circumference side and larger on the outer circumference side. Further, the address of the information in the second layer 3 is smaller on the outer peripheral side and larger on the inner peripheral side.

In order to improve the reliability of the optical disk,
The same information is recorded in both the first layer 2 and the second layer 3. In the figure, one piece of information 7 is shown as information 7-1 in the first layer 2 and as information 7-2 in the second layer 3. At this time, the same address is assigned to the same information 7-1 and 7-2 in the first layer and the second layer.

As described above, since the address starts from the inner circumference in the first layer 2 and starts from the outer circumference in the second layer 3, the address position where the same information 7-1 and 7-2 are recorded is For most information, the first layer 2 and the second layer 3 are different. According to the above-described two-layer optical disk, as will be described later, when reading information in the optical disk device, access can be performed in a short time.

A method for recording information on the above-described two-layer optical disk will be described. When information is recorded on the two-layer type optical disc 1, information is recorded from the inner side to the outer side in the first layer 2, and information is transferred from the outer side to the inner side in the second layer 3. And record. It is to be noted that a method of recording information from the outer peripheral side to the inner peripheral side of the optical disk 1 and a method of recording information from the inner peripheral side to the outer peripheral side can be both performed by known methods. The description of is omitted.

Next, an optical disk apparatus using the two-layer optical disk obtained as described above will be described with reference to the drawings. FIG. 2 shows an arrangement relationship between the optical disk 1 and the optical head 4 in the optical disk device. One optical head 4 is provided to face the first layer 2 and the second layer 3 of the information recording layer of the optical disc 1. Optical head 4
Can be moved in the radial direction of the optical disk 1 by the optical head driving unit 5 and can be stopped at an arbitrary position. The optical head 4 can read information from one of the first layer 2 and the second layer 3 by controlling the focus distance.

The optical head driving unit 5 and the optical head 4
Is controlled by the control unit 6.
The control unit 6 includes a CPU, a memory, and the like. In FIG. 2, certain information 7-1 is read by the optical head 4 at the address position B of the first layer 2, and the same information 7-2 is read by the optical head 4 at the address position A of the second layer 3. It is.

The operation of the control section 6 in the apparatus of FIG. 2 will be described with reference to the flowcharts of FIGS. In step S1, the file address information of the optical disk 1 is read and stored in the memory. In step S2, the current position A of the optical head 4 is calculated from the current address read by the optical head 4.

In step S3, the process waits for an access request to be issued.
Proceed to. In step S4, for the information 7 to be read, the physical position B of the information 7-1 of the first layer 2 and the physical position C of the information 7-2 of the second layer are calculated from the address of the access file. I do.

In step S5, the information 7-1 of the first layer 2
Physical position B and physical position C of information 7-2 of the second layer 3
Which is closer to the current position A of the optical head 4 is determined. In step S6, it is determined whether the layer corresponding to the position determined to be close in step S5 is the same layer as the layer on which the optical head 4 is currently focused.
Here, if the layer is a different layer, the process proceeds to step S7, where the optical head 4 is focused on the other layer.
Proceed to 8. If it is the same layer, the process proceeds to step S8 without changing the focus.

In step S8, the optical head 4 is moved to a physical position where the information 7 of the layer is recorded, and the information is read. In step S9, it is determined whether or not there is a reading error. If there is a reading error, the process proceeds to step S10 to access the same information recorded in the other layer.

In step S11, if there is a reading error, the process is terminated as an access error. If reading is normally performed, the process returns to step S2 to prepare for the next reading. As is apparent from the above description, when trying to read the information recorded on the optical disc 1, the information located at a position closer to the optical head 4 among the two identical information 7-1 and 7-2. Since the access is performed, the access time at the time of reading information is reduced. Further, the shortening of the access time can be easily achieved by using the same information recorded in two layers for improving the reliability of the optical disc.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made. For example, in the optical disk of FIG. 1, the address of the first layer, ie, the lower recording layer, is smaller on the inner circumference side, and the address of the second layer, ie, the upper recording layer, is smaller on the outer circumference side. can do.

In the example of FIG. 2, only one optical head is provided. However, the optical heads are provided on the upper and lower sides of the optical disk, and the upper optical head reads the upper recording layer, and the lower optical head reads the upper recording layer. The head can also read the lower recording layer. Further, the optical disc may be provided with another information recording layer in addition to the first layer and the second layer.

[0024]

According to the present invention, it is possible to obtain a multi-layer optical disk capable of improving the access performance when reading information. Further, according to the present invention, it is possible to obtain an information recording method for obtaining a multilayer optical disc capable of improving access performance at the time of reading information.

Further, according to the present invention, it is possible to obtain an optical disk device capable of rapidly reading information from a multilayer optical disk.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an optical disk of the present invention.

FIG. 2 is a diagram showing an embodiment of an optical disk device of the present invention.

FIG. 3 is a flowchart (part 1) illustrating the operation of the optical disk device of FIG. 2;

FIG. 4 is a flowchart (part 2) illustrating the operation of the optical disk device of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk 2 ... 1st layer 3 ... 2nd layer 4 ... Optical head 5 ... Drive part 6 ... Control part 7, 7-1, 7-2 ... Information

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 20/12 G11B 7/007

Claims (3)

(57) [Claims] In an optical disc having at least two layers for recording information, the address of the information in the first information recording layer is made smaller on the inner side and larger on the outer side, and the address of the information in the second information recording layer is made larger. An optical disc characterized in that the outer side is smaller and the inner side is larger, and the same information is assigned the same address and recorded on both the first information recording layer and the second information recording layer. 2. A method for recording information on an optical disc having at least two layers for recording information, wherein the first information recording layer includes a disc having an inner peripheral side and an outer peripheral side or an outer peripheral side and an inner peripheral side sequentially. Information is recorded, and the same information as the information recorded in the first device is written in the second information recording layer, in the opposite direction to the first information recording layer, from the outer circumference to the inner circumference or inside the disk. A method for recording information on an optical disk, characterized in that information is sequentially recorded from a peripheral side to an outer peripheral side. 3. An optical disc having at least two layers for recording information, wherein the same information is recorded on a first information recording layer and a second information recording layer, and the information in the first information recording layer is recorded on the first information recording layer. In the optical disc apparatus for reading information from an optical disc having a smaller outer circumference and a larger inner circumference, the address of the information in the second information recording layer is the current position of the optical head. And the physical position of the information to be read in the first information recording layer and the second position.
Means for obtaining a physical position in the information recording layer, a distance between the physical position of the first information recording layer and the current position of the optical head, a physical position of the second information recording layer, An optical disc device comprising: means for calculating a distance between a current position of an optical head; and means for moving the optical head to a physical position of the shorter of the two distances.