JP3135535B2 - Optical disk and its driving device - 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 capable of high-density recording and a driving device for the optical disk.

[0002]

2. Description of the Related Art FIG. 8 shows a configuration of an information recording surface of a conventional magneto-optical disk. A groove G, which is a substantially concentric guide groove, is formed on a conventional magneto-optical disk, and a land L is formed along the groove G. In a normal case, information pits (recording marks) are formed on the land L, and nothing is recorded on the groove G in order to read out the information pits without error.

Here, in a conventional magneto-optical disk,
Considering the case where information pits are formed on both the land L and the groove G, there is a problem that crosstalk occurs and the information pits become unreadable.

In order to solve the above problem, conventionally, MS
Super-resolution reproduction such as R (Magnetically induced Super Resolution) has been proposed. Here, the MSR will be described.

Conventionally, in the world of microscopes, it has been known that the resolution is improved by providing an optical mask such as a pinhole at the position of an object. Therefore, instead of providing a physical mask on the medium surface of the magneto-optical disk, the MSR makes use of the temperature distribution on the medium to create an effective mask in the medium, effectively reducing the spatial frequency of the reproduction limit. It is possible to increase the recording density by about 1.5 to 3 times (for more details, see "Super-Resolution Magneto-Optical Disk", Journal of the Japan Society of Applied Magnetics, Vol. 15, No. 5.19
See 91 etc. ).

[0006]

However, in the above-mentioned conventional MSR, in order to perform super-resolution reproduction, it is necessary to magnetically record information pits or address pits for generating an address.

Therefore, in the case of a disk in which address pits are recorded in advance as phase pits or the like in the same way as information pits such as a ROM disk, the super-resolution reproduction cannot be applied to the reproduction of the address pits. The pits need to be formed in a size that allows normal reproduction (normal resolution reproduction). For this reason, even if information pits are formed on both the land L and the groove G in order to improve the recording density, the address pit cannot be made to correspond one-to-one with both the land L and the groove G, and complete There is a problem that information cannot be reproduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical disk capable of accurately reading address information and reproducing recorded data even when the recording density of the optical disk is increased, and an apparatus for driving the optical disk. It is in.

[0009]

In order to solve the above problems SUMMARY OF THE INVENTION The present invention includes a recording track both formed lands and grooves in a substantially concentric recording mark is formed
Then, a mirror area is provided in a part of the recording track, and the mirror
Address pits for address reproduction are formed in the surface area
An optical disc having an address information recording area
The address pits are adjacent to each other in the radial direction of the optical disc.
The center axis of each of the land and the groove in contact with each other is
Between the axes obtained by extending into the address information recording area
And the address information recording area is
Formed on the same straight line in the radial direction on the optical disc
The radial direction of the optical disk and the axis of the recording track
Recording in the address information recording area in both directions.
The density is the area of the recording track where the recording mark is formed.
The recording density is smaller than the recording density of the area.

[0010]

According to the present invention, even when the recording density of the optical disk is increased, the address information can be read accurately, and the recorded data can be reproduced.

[0011]

Preferred embodiments of the present invention will now be described with reference to the drawings.

[0012] First Example Figure 1 shows an optical disk of a configuration of the first embodiment.

As shown in FIG. 1A, a plurality of lands L and a plurality of grooves G are provided on the magneto-optical disk, and the cross section thereof is uneven as shown in FIG. 1B. ing.

Further, on the axis of the groove G of the magneto-optical disk, a pre-pit for generating an address (phase pit:
PP (indicated by hatched circles). Area (pre-pit area) PA in which the pre-pit PP is provided
Is a mirror surface in this embodiment (see FIG. 1C).

The length (normal direction) of the prepit PP is generally longer than the information pit (indicated by a circle in the figure), and the width (radial direction) of the prepit PP is defined by the groove G. (See FIG. 1D).

FIG. 2 is a schematic block diagram of a magneto-optical disk recording / reproducing apparatus. The magneto-optical disk recording / reproducing apparatus includes a spindle motor 1 for rotating and driving the magneto-optical disk DK, a magnetic head 2a, and an optical pickup 2b.
It has an actuator (not shown) that moves in the radial direction of K, a laser light source, a lens, a photodetector, and the like, and irradiates a laser beam spot to the magneto-optical disk DK during data recording / reproduction, and emits light when reproducing data. The magnetic Kerr in the spot-irradiated magneto-optical disk DK
RF that is obtained by detecting the intensity of reflected light generated by the polarization plane slightly rotating due to the effect, and photoelectrically converting the intensity.
(Radio Frequency) signal is output.

The magneto-optical disk recording / reproducing apparatus has a spindle servo circuit 3 for controlling the spindle motor 1.
Pickup 2 for irradiating the magneto-optical disk DK
a focus servo circuit 4 for controlling the focus of the light spot from b, a tracking servo circuit 5 for controlling the movement of the magnetic head 2a and the optical pickup 2b to the track position, a head servo circuit 6 for controlling the magnetic head 2a, A head amplifier 7 for amplifying an output signal of the optical pickup 2b, and an RF amplifier 8 for generating and outputting a reproduction signal and various signals for control from an output of the head amplifier 7
An EFM decoder 9 for demodulating a read EFM signal output from the RF amplifier 8 at the time of data reproduction and outputting digital output data; a system controller 10 for controlling the entire apparatus at the time of data reproduction; An operation unit 11 is provided with an operation switch, such as a reproduction switch (PLAY), to which an operation is input, and a display unit 12 for performing various displays during data reproduction.

Next, the operation will be described with reference to the processing flowchart of FIG. In the following description, the least significant bit of the address data indicates whether the position where the information pit is to be reproduced or recorded is on the land L or on the groove G. Specifically, basic address data = "for specifying a set of lands and grooves to which lands L for reproducing or recording information pits belong"
0100 ", and the bit information indicating the land L is X
If (X: 0 or 1), address data = “01”
00X ". In this case, the target basic address data is recorded on the groove G, and both the inner and outer peripheral sides of the groove G have the land L.
Therefore, it is necessary to determine in advance whether the land corresponding to the basic address data is an inner land or an outer land. As a result, when the groove indicated by the basic address data is detected, as shown in FIG. 4, it is monitored whether the tracking error signal swings to the plus side or the minus side to jump immediately to the correct land. be able to.

First, the system controller 10 controls the tracking servo circuit 5 so as to trace the groove (step S1). Next, the system controller 10 reads the current address data (basic address data) obtained through the pickup 2b, the head amplifier 7, the RF amplifier 8, and the EFM decoder 13 by irradiating the pre-pit with a light spot (Step S).
2) Compare with a portion of the target address data except for the least significant bit, and seek to a target track (= a set of land and groove) (step S3).

When reaching the target track, the system controller 10 sets the least significant bit (=
X) to determine whether or not the final destination address data corresponds to the groove (step S4).

[0021] When the final target address of a groove G is the corresponding base address data is recorded in the present embodiment, since it is on the groove G, the seek process already become to have reached finish.

If the final destination address is a land, the system controller 10 controls the tracking servo circuit 5 to change the tracking servo to the land L.
Is switched to trace, and the pull-in to the land L ends the seek processing (step S5).

Thereafter, the system controller 10
Of information pits recorded on lube G or land L
A super-resolution reproduction operation is performed. As described above, the first
referenceAccording to the example, information pits capable of super-resolution reproduction and communication
When address pits that can only be played back are mixed
Fully recorded without being affected by crosstalk
Data can be reproduced and the recording density of the magneto-optical disk
The degree can be improved.

[0024] Second Example Figure 5 shows an optical disk of a configuration of the second reference example. The second participation
Considered example is obtained when a pre-pits in the land.

As shown in FIG. 5A, the magneto-optical disk is provided with a plurality of lands L and a plurality of grooves G, and the cross section thereof is uneven as shown in FIG. 5B. ing.

Further, a pre-pit (phase pit) PP for generating an address is provided on the axis of the land L of the magneto-optical disk. In the case of the present embodiment, a groove G is provided in parallel also in the area (pre-pit area) PA in which the pre-pit PP is provided (see FIG. 5A).

The length (normal direction) of the pre-pit PP is generally longer than the information pit (indicated by a circle in the figure) (see FIG. 5A), and the width of the pre-pit PP is large. (Radial direction) is substantially equal to or less than the width of the land L (see FIG. 5C).

The test measures the operation of the target address in this case is substantially the same as that of the first reference example, in the description of the first reference example, it In other read land L and the groove G. According to the second reference example, as in the first reference example, even when information pits capable of super-resolution reproduction and address pits capable of only normal reproduction are mixed, there is no effect of crosstalk or the like. The recorded data can be reproduced quickly, and the recording density of the magneto-optical disk can be improved.

First Embodiment FIG. 6 shows the configuration of an optical disk according to an embodiment of the present invention .
This real施例, upon providing the prepits PP, in which the central axis of the prepit PP is provided so as to be positioned between the central axis of the land the groove.

As shown in FIG. 6A, a plurality of lands L and a plurality of grooves G are provided on the magneto-optical disk, and the cross section thereof is uneven as shown in FIG. 6B. ing.

Further, prepits (hatched circles in the figure) are provided between the axis of the groove G and the axis of the land L of the magneto-optical disk so that the axis of the prepit (phase pit) PP for generating an address is located. The area (pre-pit area) PA where the pre-pits are provided is a mirror surface in the case of the present embodiment (see FIG. 6C).

The length (normal direction) of the prepit is generally longer than the information pit (indicated by a circle in the figure), and the width (radial direction) of the prepit is defined by the groove G.
The width is substantially equal to or less than the width obtained by adding the width of the land L (see FIG. 6D).

Next, the operation will be described with reference to the processing flowchart of FIG. In the following description, the position where the information pit is to be reproduced or recorded is the same as in the first reference example.
Whether it is on a land or a groove is indicated by the least significant bit of the address data.

In this case, the target basic address data is recorded as pre-pits between the axis of the groove G and the axis of the land L, and the groove G or the outer periphery of the pre-pit is located on the inner and outer sides. Since the land L exists and the target groove G or land L is unambiguously determined, whether to jump inward or outward corresponding to the basic address data in advance as in the first reference example is determined. There is no need to set the value, and it is possible to immediately jump to the correct land or groove by simply monitoring whether the tracking error signal swings to the plus (+) side or the minus (-) side.

First, the system controller 10 controls the tracking servo circuit 5 so as to trace the groove G or the land L (step S1).
0). In this real施例, this setting is no problem even if any of the groove G or the land L.

Next, the system controller 10 controls the tracking servo circuit 5 to apply an offset voltage to the pickup 2b so that the read beam moves between the axes of the groove G and the land L (step S11). As a result, the read beam moves between the axes of the groove G and the land L, and a signal corresponding to the pre-pit can be read.

[0037] Then the system controller 10, the pickup 2 by irradiating a light spot flop le pit <br/> Tsu DOO
b, head amplifier 7, RF amplifier 8, EFM decoder 1
3, the current address data (basic address data) obtained through step 3 is read (step S12), compared with the portion of the target address data except the least significant bit, and the tracking servo circuit 5 is controlled again to control the groove G.
Alternatively, a setting is made to trace the land L (step S13). Then, seek is performed near the target track (= a set of land and groove) (step S1).
4).

Next, the system controller 10 controls the tracking servo circuit 5 again to apply an offset voltage to the pickup 2b so that the read beam moves between the axes of the groove G and the land L (step S15). . As a result, the read beam moves between the axes of the groove G and the land L, and can read a signal corresponding to the pre-pit.
Pickup 2b, head amplifier 7, RF amplifier 8, E
The current address data (basic address data) obtained via the FM decoder 13 is read (step S16),
A comparison is made with a portion of the target address data excluding the least significant bit to determine whether or not the target track has been reached (step S17).

When reaching the target track, the system controller 10 sets the least significant bit (=
X) to determine whether the final destination address data corresponds to the groove, and jump to the groove G or land L (step S18).

Thereafter, the system controller 10 performs a super-resolution reproduction operation of the information pits recorded on the groove G or the land L. If the target track has not been reached, the processing of steps S13 to S17 is repeated until the target track is reached.

[0041] As described above, according to the present real施例,
As in the first and second embodiments, even when information pits capable of super-resolution reproduction and address pits capable of normal reproduction are mixed, recorded data is completely reproduced without being affected by crosstalk or the like. Thus, the recording density of the magneto-optical disk can be improved.

In the above embodiment, the land L and the group G are provided on the optical disk.
The present invention is also applicable to an optical disk having no group G.

[0043]

According to the present invention, even when the recording density of the optical disk is increased, the address information can be read accurately, and the recorded data can be reproduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an optical disc according to a first embodiment.

FIG. 2 is a block diagram showing a schematic configuration of a magneto-optical disk drive.

FIG. 3 is an operation processing flowchart of the first embodiment.

FIG. 4 is an explanatory diagram of a tracking error signal.

FIG. 5 is a diagram illustrating a configuration of an optical disc according to a second embodiment.

FIG. 6 is a diagram illustrating a configuration of an optical disc according to a third embodiment.

FIG. 7 is an operation processing flowchart of the third embodiment.

FIG. 8 is a diagram illustrating a configuration of a conventional optical disc.

[Explanation of symbols]

 Reference Signs List 1 spindle motor 2a magnetic head 2b pickup 3 spindle servo control circuit 4 focus servo control circuit 5 tracking servo control circuit 6 head servo control circuit 7 head amplifier 8 RF amplifier 9 EFM decoder 10 system Controller 11 ... Operation unit 12 ... Display unit G ... Groove L ... Land

Claims (2)

(57) [Claims] Recording tracks 1. A recording marks both lands formed in a substantially concentric and grooves are formed and
Then, a mirror area is provided in a part of the recording track, and the mirror
Address pits for address reproduction are formed in the surface area
An optical disc having an address information recording area, wherein the address pits are offset in a radial direction of the optical disc.
The center axis of each of the adjacent lands and grooves is set forward.
Between the axes obtained by extending the address information recording area
And the address information recording area is formed on the optical disc.
It is formed on the same straight line in the radial direction, and is formed in both the radial direction of the optical disc and the axial direction of the recording track.
The recording density of the address information recording area in the direction
Is the area of the recording track where the recording mark is formed.
An optical disc characterized by being smaller than a recording density. 2. The optical disk according to claim 1, which is driven.
An optical disk drive device, a driving unit for driving the optical disk, and irradiating the optical disk with a light beam, and
Optical pickup that receives the reflected light and outputs a read signal
Optical disk drive system including a flop, and a demodulation means for demodulating the read signal.