JPH0757279A - Method for controlling optical disk device - Google Patents

Abstract

PURPOSE:To prevent a land part and a groove part from erroneously accessing in an optical disk device provided with a function recording information on both of the land part and the groove part by performing the access operation of an optical disk after deciding the correspondence of a tracking control condition with a tracking position by tentative tracking operation. CONSTITUTION:An optical pickup is tracked out tentatively the land part L or the groove part G of a fixed area on the optical disk, and whether a tracked position is the land part L or the groove part is discriminated, and the correspondence of the tracking control condition with the tracking position is decided. Then, when the instruction information whether accessing to the land part or the groove part is received, the optical pickup is tracked out the land part L or the groove part G by the dealing tracking control condition, and the recording and reproducing operation of the information is conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling an optical disk drive which uses an optical disk having a track guide groove and has a function of accessing both a land portion and a groove portion of the optical disk.

[0002]

2. Description of the Related Art Generally, in the case of an optical disc having a track guide groove, information is recorded on either a groove portion which is a track guide groove or a land portion sandwiched by the groove portions.

On the other hand, for example, Japanese Patent Laid-Open No. 4-195
Japanese Patent No. 939 proposes that information is recorded on both the land portion and the groove portion to double the recording capacity of the optical disc.

By the way, it is necessary to preliminarily record address information on the optical disc by pre-pits for each information sector.

In the above proposed optical disc, the pre-pits are formed at the boundary between the land portion and the groove portion. As a result, the same address information is read both when the optical pickup tracks the land portion to access the land portion and when the optical pickup tracks the groove portion to access the groove portion.

A track number and a sector number are recorded in the address portion, and the optical disk device identifies the target sector based on the information.

Therefore, in the case of the above configuration, since the same sector number is given to the land portion and the groove portion, the land portion and the groove portion must be correctly discriminated when accessing the optical disc.

By the way, a push-pull method utilizing a diffraction phenomenon of reflected light from a land portion and a groove portion is often employed for tracking control of an optical disk. The tracking error signal obtained by this push-pull method changes to a signal level "0" when there is no tracking deviation, a "+" level when it deviates to one side, and a "-" level when it deviates to the other. Further, in this case, the positive and negative polarities of the signal have opposite polarities when the optical pickup is tracked to the land part and when the optical pickup is tracked to the groove part.

Therefore, the tracking error signal is "+".
At the time of level, whether the optical pickup is to be tracked to the land part or the groove part is changed only by changing the tracking control condition such as moving the optical pickup to the outer circumference side or the inner circumference side of the optical disc. , Can be easily switched.

However, for example, when the tracking is performed on the land portion at a specific time, which of the tracking control conditions should be set depends on the circuit of the optical disk device and is different for each device.

For this reason, for example, it is expected that a setting error will occur such that the user sets the tracking control condition in an attempt to record information on the land portion but actually records on the groove portion. . In this case, if there is record information in the groove portion, the record information will be destroyed.

[0012]

As described above, the prior art is as follows.
In the case of an optical disc that uses both the land portion and the groove portion, there is a problem that the land portion and the groove portion are easily accessed by mistake.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a control method for an optical disk device which prevents the land portion and the groove portion from being accessed by mistake.

[0014]

To this end, according to the present invention, an optical pickup is experimentally tracked in a certain area of an optical disc without knowing whether it is a land portion or a groove portion, and then the tracked position is changed. It is determined whether it is a land portion or a groove portion, and the correspondence between the tracking control condition and the tracking position is determined, and then, the command information for accessing the land portion or the groove portion is received, The optical pickup is tracked to the designated position under the corresponding tracking control condition to execute the information recording / reproducing operation.

[0015]

In the trial tracking operation, the correspondence between the tracking control condition and the tracking position is determined, and then the access operation of the optical disk is executed in accordance with the command information. Therefore, the land portion and the groove portion can be accessed by mistake. Can be prevented.

[0016]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of an optical disk device according to an embodiment of the present invention. In the figure,
The optical disc 1 is, for example, a write-once recording medium of a punching recording system, and is fixed to a rotation shaft of a spindle motor 2 so as to rotate. A seek motor 3, a moving optical system 41 driven by the seek motor 3 in the radial direction of the optical disk 1, and a position sensor 5 for detecting the position of the moving optical system 41 are arranged below one side of the optical disk 1. It is set up. A fixed optical system 42 is arranged beside the moving optical system 41. Moving optical system 41 and fixed optical system 4
The numeral 2 constitutes the optical pickup 4.

In the fixed optical system 42, a light source section 421 for emitting a laser beam and a light detecting section 422 for detecting the reflected light from the optical disk 1 are housed. In the moving optical system 41, a mirror 411 for forming an optical path between the optical disc 1 and the fixed optical system 42, an objective lens 412 for condensing the laser light with which the optical disc 1 is irradiated, and its biaxial actuator 413 are provided. A biaxial actuator 413 that drives the optical disc 1 in the radial direction and in the direction perpendicular to the disc surface is housed.

As shown in FIG. 2, the optical disc 1 of this embodiment has a groove portion G and a land portion L of 0.8 μm, for example.
They are formed with the same width of about m. Also, the groove portion G
The land portion L level difference is set to about ⅛ of the wavelength λ of the irradiation light. A part of the track area is set in the land / group identification area 11, and the remaining part is set in the user information recording area 12.

In the land portion L of the land / group identification area 11, prepits are formed over the entire circumference of the disc. This prepit has a land portion L and a groove portion G.
It is for distinguishing between. On the other hand, in the recording area 12, several tens of information sectors are formed per track, and the header portion 12a of each information sector is formed with prepits indicating address information. This address information is known information indicating a track number and a sector number.

FIG. 3 shows a signal circuit of the optical disc device. In the figure, two-divided light receiving elements 422a, 422
Both 22b are arranged in the photodetector 422. The two-division light receiving element 422a detects a focus error by a known knife edge method.
The divided light receiving element 422b detects a tracking error by the known push-pull method.

The two detection signals of the two-divided light receiving element 422a are input to the subtraction circuit 601, and the output of the subtraction circuit 601 is input to the focusing control unit 602.
The focusing control unit 602 executes focusing control of the laser light with which the optical disc 1 is irradiated.
The shaft actuator 413 is controlled in one direction.

The two detection signals of the two-divided light receiving element 422b are input to the subtraction circuit 603 and the addition circuit 604. The output of the subtraction circuit 603 is the tracking control unit 60.
It is entered in 5. The tracking control unit 605 executes tracking control of the laser beam applied to the optical disc 1, and controls the biaxial actuator 413 in the other direction.

The output of the adder circuit 604 is the signal reproduction unit 60.
It has been entered in 6. The signal reproducing unit 606 reproduces the recorded information on the optical disc 1. The control unit 607
Each part is monitored and controlled. Then, the control unit 607
Receives various commands from a host computer (not shown), and executes control operations for recording / reproducing information on / from the optical disc 1 in accordance with the commands.

With the above configuration, it is assumed that the optical disk device of this embodiment is powered on and the device operation has started.

In this case, the optical disk device seeks the optical pickup 4 to a specified position in the land / group identification area 11 of the optical disk 1 as shown in FIG. 4 (process P).
01). The seek operation of the optical pickup 4 is
This is an operation of driving the moving optical system 41 by the seek motor 3. At this point, it is unknown whether the seek position is the land portion L or the groove portion G.

Then, focusing control is started.
That is, laser light is emitted from the fixed optical system 42, and the emitted light is condensed by the moving optical system 41 and applied to the optical disc 1 as spot light. The reflected light from the optical disk 1 returns to the fixed optical system 42 through the opposite path, and
Detected at 22. In this case, a difference occurs between the two detection signals of the two-divided light receiving element 422a depending on the focus shift of the laser spot irradiating the optical disc 1. This is a known operation of the knife edge method. The subtraction circuit 601 outputs this difference as a focusing error signal Fo. The focusing control unit 602 adjusts the biaxial actuator 41 so that the focusing error signal Fo is minimized.
Drive 3 As a result, the focus of the laser light applied to the optical disc 1 is adjusted (process P02).

Next, the tracking control is started.

By the way, although the laser spot is radiated to either the land portion L or the groove portion G at present, in either case, the two-divided light receiving element is selected depending on the deviation of the irradiation position with respect to their center position. A difference occurs between the two detection signals of 422b. This is a known operation of the push-pull method. The subtraction circuit 603 outputs the difference between the two detection signals as a tracking error signal Tr.

Therefore, this tracking error signal Tr
As shown in FIG. 5, with respect to the land portion L or the groove portion G, "0" is set in the on-track state where there is no positional deviation of the laser spot, "1" is shifted to the "+" level, and one is shifted to the other. At that time, it changes to the "-" level.

The tracking control is an operation of moving the irradiation position of the laser spot so that the tracking error signal Tr is minimized. In this embodiment, as shown in FIG. 6, "control mode 1" and "control mode 1" are used. It has two control modes of "control mode 2". In the "control mode 1", when the tracking error signal Tr is at the "+" level, the irradiation position of the laser spot is moved to the outer peripheral side of the optical disc 1, and when it is at the "-" level, it is moved to the inner peripheral side. In the "control mode 2", contrary to the above, when the level is the "+" level, the inner side is moved, and when the level is the "-" level, the outer side is moved.

In this embodiment, first, tracking control is executed in "control mode 1" (process P03). At this time,
Either the land portion L or the groove portion G is tracked. Which is tracked depends on the device circuit.

Then, the reproduced signal is detected. That is,
When there is recorded information at the position where the tracking has just been performed, the two detection signals of the two-divided light receiving element 422b both change. The adder circuit 604 adds the two signals and outputs it as a reproduction signal Rf. The signal reproducing unit 606
The reproduced signal Rf is binarized and output. Then, the control unit 607 determines the presence or absence of the reproduction signal Rf (process P04).

Next, the control mode is switched to "control mode 2" and the tracking control is executed again (process P05). As a result, for example, when the land portion L has been tracked in the “control mode 1”, the tracking position moves to the groove portion G adjacent to the land portion L. Further, when the groove portion G is being tracked in the "control mode 1", the tracking position is moved to the land portion L adjacent to the groove portion G. Then, the presence or absence of the reproduction signal Rf is determined (process P).
06).

Thereafter, the reproduction signal Rf is detected in one of the two tracking controls and it is determined whether or not the reproduction signal Rf is not detected in the other (process P07). Here, if the reproduction signal Rf is detected by both of the two tracking controls, or is not detected by both of the two tracking controls (process P0).
7N), an error message is displayed (process P08), and the operation ends. This means that the optical disk 1 is not the optical disk described with reference to FIG.

On the other hand, if the reproduction signal Rf is correctly detected in only one of the two tracking controls (process P
07), where the tracking control conditions for the land portion L and the groove portion G are determined. For example, now
As shown in FIG. 7A, when the reproduction signal Rf is detected in the “control mode 1” and not detected in the “control mode 2”, the “control mode 1” is accessed when the land portion L is accessed. It is determined that the tracking control is executed in step S4 and the tracking control is executed in the "control mode 2" when the groove portion G is accessed. On the other hand, as shown in FIG. 2B, when the reproduction signal Rf is not detected in the “control mode 1” but is detected in the “control mode 2”, the land portion L
It is determined that the tracking control is executed in the "control mode 2" when accessing the track and the tracking control is executed in the "control mode 1" when accessing the groove portion G (process P09).

Thereafter, the read / write command sent from the host computer is monitored (N in process P10).
Loop). In the present embodiment, it is assumed that the read / write command indicates, together with the number of the information sector, whether the access target is the land portion L or the groove portion G.

When the optical disk device receives the read / write command from the host computer (Y in process P10), it seeks the optical pickup 4 to the track position where the corresponding information sector in the recording area 12 exists (process P1).
1). Then, the tracking control is executed in the control mode corresponding to the land portion L or the groove portion G according to the tracking control condition determined in the process P09 (process 1).
2). As a result, the land portion L is
Alternatively, it is possible to reliably track the groove portion G.

After this, information is recorded in the corresponding information sector of the tracked land portion L or groove portion G, or the recorded information of the information sector is read (process P13). When this access operation ends, the process returns to command monitoring (to process P10).

As described above, the optical disc apparatus of this embodiment has two tracking control modes as shown in FIG. 6, and on the other hand, the land / group identification area 11 of the optical disc 1 is tested. Tracking is performed to determine whether the tracking position is the land portion or the groove portion, the correspondence between the tracking control mode and the tracking position is determined, and then the read / write command is used to determine the land portion L or the groove portion. When G is instructed, tracking control is executed according to the determination result.

As a result, it is possible to prevent the land portion and the groove portion from being accessed by mistake.

The header portion 12a of the recording area 12 of the optical disc 1 is shared between the case of accessing the land portion L and the case of accessing the groove portion G.
It is not possible to distinguish between the land portion and the groove based on the address information of 2a. Therefore, it is especially necessary not to mistake the land portion and the groove portion.

Further, in the land / group identification area 11, a prepit is formed only in the land portion L, so that whether the test-tracked position is a land portion or a groove portion is determined. Therefore, it is possible to make a reliable judgment by a simple means.

In the above embodiment, the pre-pits in the land portion L of the land / group identification area 11 do not represent meaningful information, but the pre-pits represent control information such as optical disc drive conditions. You may do it. In an ordinary optical disc, an SFP (Sector format Par) that is a control track is used.
Although the control information is recorded in t) or the like, the operation of reading the control track can be omitted by the above.

FIG. 8 shows another embodiment of the optical disc 1. The difference from FIG. 2 is that the prepits of the land / group identification area 11 are eliminated, the groove portions of the groove portion G are intermittently formed, and the adjacent groove portions are arranged in a staggered pattern.

In this case, when the optical pickup 4 is tracked to the land portion L of the land / group identification area 11, the reproduced signal Rf is not detected, and when the optical pickup 4 is tracked to the groove portion G, the reproduced signal Rf is detected. This allows
The land portion L and the groove portion G can be discriminated from each other as in the above-described embodiment.

On the other hand, in the land / group identification area 11, for example, as shown in FIG. 9A, the width of the groove portion G may be narrower than the width of the land portion L. In this case, since there is a difference in reflectance between the two laser light,
The land portion L and the groove portion G can be discriminated by detecting the intensity difference of the reflected light.

Further, for example, as shown in FIG.
If the groove portion of the groove portion G is formed intermittently, when the groove portion G is tracked, it can be detected as a reproduction signal Rf.

As an example of the land / group identification area 11, the prepits are formed in the land portion L in FIG. 2, but may be formed in the groove G. In addition, FIG.
In (a) and (b), the groove portion G is formed narrower, but the land portion L may be formed narrower.

In each of the above embodiments, the optical disc 1
Is a write-once recording medium of a hole recording system, but for various optical discs having a track guide groove,
The present invention can be applied similarly. For example, it goes without saying that a rewritable recording medium of a magneto-optical recording system or a phase change recording system may be used. Further, it can be applied to optical cards and optical tapes that store information on the same principle.

[0051]

As described above, according to the present invention, the optical pickup is tentatively tracked in a certain area of the optical disc under a constant control condition to determine whether the tracking position is a land portion or a groove portion. After determining the correspondence between the tracking control condition and the tracking position based on the result of the determination, the optical disc is accessed according to the command information, so that it is possible to prevent the land portion and the groove portion from being accessed by mistake. become able to.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an optical disc device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an information recording surface of an optical disc.

FIG. 3 is a block configuration diagram of a control circuit.

FIG. 4 is an operation flowchart of the optical disk device.

FIG. 5 is an explanatory diagram of a tracking error signal.

FIG. 6 is an explanatory diagram of a tracking control mode.

FIG. 7 is an explanatory diagram of a tracking control condition determining method.

FIG. 8 is an explanatory diagram showing another embodiment of the information recording surface of the optical disc.

FIG. 9 is an explanatory diagram showing still another embodiment of the information recording surface of the optical disc.

[Explanation of symbols]

 1 Optical Disc 2 Spindle Motor 3 Seek Motor 4 Optical Pickup 5 Position Sensor 11 Land / Group Identification Area 12 Recording Area 12a Header Section 41 Moving Optical System 42 Fixed Optical System 411 Mirror 412 Objective Lens 413 Biaxial Actuator 421 Light Source Section 422 Optical Detection Section 422a, 422b Two-divided light receiving element 601, 603 Subtraction circuit 602 Focusing control unit 604 Addition circuit 605 Tracking control unit 606 Signal reproducing unit 607 Control unit G Groove unit L Land unit

Claims (6)

[Claims] 1. An optical disk apparatus having a function of switching between two states of tracking control conditions to selectively track an optical pickup to a land portion or a groove portion of the optical disc and accessing both the land portion and the groove portion. In the control method, the optical pickup is experimentally tracked to a land portion or a groove portion in a certain area of the optical disc, and it is determined whether the tracked position is a land portion or a groove portion, and the tracking control condition and the tracking position are set. When receiving the command information to access the land part or the groove part, the optical pickup is tracked to the land part or the groove part under the corresponding tracking control condition to record and reproduce the information. Optical disc characterized by performing operations Device control method. 2. When performing the recording / reproducing operation of the information, the address sector of the pre-pit formed at the boundary between the groove portion and the land portion is read to identify the information sector. Item 1. A control method for an optical disk device according to item 1. 3. In a certain area of the optical disk, a prepit is formed only on one of a land portion and a groove portion, and it is determined whether the tracked position is a land portion or a groove portion depending on the presence or absence of the prepit. The method of controlling an optical disk device according to claim 1, wherein 4. The control method for an optical disk device according to claim 3, wherein the pre-pit indicates control information of the optical disk. 5. A groove portion is intermittently formed in a certain area of the optical disc, and it is determined whether the tracked position is a land portion or a groove portion depending on whether or not there is a change in intensity of reflected light of the emitted laser light. The method of controlling an optical disk device according to claim 1, wherein: 6. In the fixed area of the optical disk, a groove portion and a land portion are formed with different widths, and whether the position tracked by the intensity of reflected light of the emitted laser light is the land portion or the groove portion. The method for controlling an optical disk device according to claim 1, wherein