JP2560812Y2 - Optical disk drive - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to an optical disk device.
In particular, the present invention relates to a control device that enables an optical head to follow a surface deflection of an optical disk.

[0002]

2. Description of the Related Art In a conventional optical disk apparatus, FIG.
As shown in FIGS. 11 to 11, control of the optical heads 21 and 22 so that the optical axis 23 of the optical heads 21 and 22 is perpendicular to the storage surface 24 of the optical disk 2 with respect to the surface deflection 20 in the radial direction 19 of the optical disk 2. A method has been proposed.

A conventional optical disk device 25 shown in FIG.
An optical head 21 facing the optical disc 2;
And the optical disk surface deflection detecting means 26 mounted on the optical disk. In a conventional control method of the optical head 21 of the optical disk device 25, the amount of the surface runout 20 of the optical disk 2 is detected by the optical disk surface runout detecting means 26, and the optical axis 23 of the optical head 21 is detected by the detection output. 24.

A conventional optical disk device 27 shown in FIG. 10 includes an optical head 22 facing the optical disk 2 and a skew (optical disk 2) at any two or more radial positions from the inner circumference to the outer circumference of the optical disk 2. (Vertical degree of the optical axis of the optical head 22 with respect to the recording surface 24). The control method of the optical head 22 of the optical disk 2 is as follows.
As a result of actually measuring the skew angles of a plurality of optical disks, FIG.
Paying attention to the fact that there is such a tendency as shown in (a) and (b), the detection output from the skew detection means 28 installed at the radial position of the optical disk 2 and the position of the optical head 22 from, for example, a potentiometer The output of the optical head 2 is calculated by inputting the output of
2 was used to correct the skew angle.

[0005]

In the conventional optical head control method for an optical disk apparatus shown in FIG. 9, a skew correction operation starts from a time when a seek operation is performed from one track to another track. Tracking of the optical head is delayed , and accurate positioning of the optical head cannot be performed. In the conventional optical head control method for an optical disk device shown in FIGS. 10 and 11, the skew angles of a plurality of optical disks in the radial direction are measured, and it is concluded that the skew angle is constant or the change of the skew angle is constant. Although the following of the optical head is not delayed from the time of seek from the track to the other track for the skew correcting operation start Umate also the plane of the optical disc runout, those changes in the skew angle or skew angle in the radial direction of the optical disk is constant However, the skew correction operation may be delayed because the optical head does not follow the surface deviation of the optical disk, and accurate optical head positioning may not be performed. This is shown in FIG. As shown in FIG. 12, when the skew angle (or the change of the skew angle) in the radial direction of the optical disc is not constant and changes as shown in FIG.
When seeking from one track to the other track, the optical head operates to follow the skew angle of the optical disk, but starts operation after detecting the skew angle of the optical disk. The correction of the skew angle of the optical head is delayed, so that as shown in the figure, when the optical head arrives at the other track , the correction skew angle of the optical head is the skew angle of the optical disk.
Not meet the, it will appear as a deviation amount of the skew angle of the optical disk and the optical head shown in FIG. FIG. 9-
The optical head control method of No. 11 proposes skew correction in the radial direction of the optical disk, and cannot be applied to the circumferential runout of the optical disk in the circumferential direction.

In the method shown in FIG. 9, since the optical disk surface deflection detecting means is mounted on the optical head,
The weight of the optical head becomes heavy, and as a result, the seek time of the optical head becomes long, which causes a decrease in the function of the apparatus. In addition, since the optical disk surface deflection detecting means has an optical mechanism like the optical head, it is expensive . There was .

Also, the methods shown in FIGS. 10 and 11 are expensive because they require a plurality of skew detecting means having the same optical mechanism as in FIG. Furthermore, Japanese Patent Application Laid-Open No. 3-228230
No. “Surface runout measuring device” uses an optical head on an optical disc.
Focus actuator that applies focus servo to
Surface runout is measured from the drive signal of the motor.
An apparatus is disclosed. However, this one just
The amount of runout of the optical disk is simply calculated from the focus drive signal.
Is only used for measurement, and is effective for reducing measurement time
However, specific disclosure on how to use the measurement results is
Not done, of course, use of measurement results
Open any necessary surface runout storage means and their usage forms.
It was clear that it was not. Also, JP
No. 4-1937 "Tracking control device"
The tracking position is
Tracking error signal because it changes according to the position above
Measure the offset that occurs in the
An apparatus that enables king control is disclosed.
However, before playing the disc, the extremes of the reflected light
Alternatively, the value of the tracking error signal at the maximum point is
Measurement in several areas of the
It is necessary to store it as the data on the location of the object. Also,
As a means for storing the tracking position data
The required tracking target position memory is provided in the device.
Therefore, each time the optical disk is replaced, a new
It is necessary to re-collect the packing position data,
It takes time to execute racking control
And had problems such as lack of practicality. Sa
In addition, Japanese Patent Laid-Open No. 4-19833, "Optical disk device"
Of the servo control at multiple positions on the optical disk
Optical disc to give
Divided into multiple areas, and offset each area.
Default values and calibration values such as servo gain in the mapping memory.
A device for storing the information is disclosed. But
However, this is the optimal value calculated by the microprocessor.
A memory that stores the offset amount as map data is provided.
The optical disk is exchanged for this purpose.
Each time it is necessary to re-collect the optimal offset amount,
Although it is necessary to execute accurate servos, it takes time and effort
However, it has problems such as lack of practicality.

[0008]

SUMMARY OF THE INVENTION Accordingly, in order to achieve the above-mentioned object, the present invention provides an optical head for rotating an optical disk.
Optical disk drive that reads and writes information by scanning in the radial direction
In the above, the surface runout information specific to the optical disk
Information storage medium that stores the information
Reading means for reading the surface runout information at any time;
Receiving a seek command to move the optical head to the target track
And operates the readout means to store the surface runout information.
Reads out runout information on the target track from the medium
At the time when the optical head moves to the target track.
Control means for applying a posture servo based on the surface runout information;
It is characterized by having .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. In FIG. 1, an optical disk device 1
Comprises an optical disk 2, a spindle motor 3 for rotating the optical disk 2, an optical head 4 for reading and writing information on the optical disk 2, a storage unit 5, a calculation unit 6, and a control unit 7. The surface of the optical disc 2 shake information
An optical disc is stored in the storage unit 5 which is a reading unit for reading the data.
The runout information storage medium 8 storing the runout information of the
The device is detachably mounted. This surface run-out information storage medium 8
Stores the runout information specific to the optical disc 2 as an actual measurement value
The optical disk 2 is used by being attached to the optical disk 2.

Next, the operation will be described. As shown in FIG. 2, when a seek command is issued to the optical head 4, the optical head 4 moves from one track 9 to the other track 10 in the arrow direction 11, and moves the optical disk 2 in the arrow direction 12 on the optical disk 2. due to the rotation, but moves in the direction of arrow 13, each surface 14 in the circumferential direction lever and as an example, the optical disk 2 is one of the tracks 9 and the other track 10 of the optical disc 2 as shown in FIG. 3 There are surface runout patterns 15 and 16 caused by distortion in a direction perpendicular to. FIG.
When the optical head 4 moves from one track 9 to the other track 10 as shown in FIG. 7, the optical head 4 moves in the arrow direction 11 as described above, but the optical disc 2 rotates in the arrow direction 12 as described above. On the optical disk 2, the optical head 4 moves in the arrow direction 13 and reaches the position 17.

Therefore, when the optical head 4 reaches the position 17 of the optical disk 2, the optical head 4 is positioned corresponding to the distortion 18 of the optical disk 2, and the subsequent operation of the optical head 4 is performed in the storage section of the optical disk device 1. Surface inserted in 5
It is controlled by the runout information of the optical disc 2 stored in the runout information storage medium 8 .

Here, the surface runout information storage medium 8 is further described.
To explain in detail, the surface vibration information storage medium 8 are those such as ROM card, this is surface deflection information of each optical disc 2 is stored, individual light di
Since it is unique to the disc 2, the surface runout information storage medium 8
Is attached to the corresponding optical disc 2 as a dedicated medium . As shown in FIG. 5, the method of storing the surface runout information is to measure the surface runout using a surface runout measuring device or the like prepared at an interval of about 1 mm in the radial direction of the optical disc 2 and store this information in a ROM card or the like. It is a way to memorize. Note that the measurement interval is not specified to 1 mm.

Next, FIG. 6 shows a flow in which the optical head 4 is controlled by the surface runout information of the medium 8. If from one track 9 is seek command to the other track 10 Heshiku, position information of one of the tracks 9 and the other track 10 is Ru entering the means for receiving the positional information of the operation portion 6 of the optical disc apparatus 1. Therefore , the calculation unit 6 calculates the time required for seeking from one track 9 to the other track 10 by calculation means, and the calculation unit 6 obtains from the storage unit 5 positional information on which the distortion has been measured . And the other track 1
The position at which the distortion is measured closest to the other track 10 is determined by the selection means from the position information of 0 and the storage unit 5.
The surface runout pattern at this position is obtained from. Furthermore ,
A surface vibration pattern at the measurement position of the closest strain duration and other track 10 calculated by the above-mentioned calculation means, the surface at the time the optical head 4 is completed seeks to other track 10 deflection pattern From the above, the surface wobble mode at the time when the optical head 4 completes the seek to the other track 10 is determined by the determination means.

The control unit 7 includes an optical head 4 as shown in FIG.
There at the time the seek to the other track 10 has been completed, and controls the driving of the optical head to follow the surface deflection mode of the optical disc 2 which is indexed by the arithmetic unit 6, hereinafter, closest to the other track 10 the optical head 4 is controlled in accordance with surface deflection pattern at the measurement position of the strain.

Therefore, according to this optical head control method,
As shown in FIG. 8, the optical head 4 can follow the surface deflection of the optical disk 2 without time delay.

The storage capacity of the medium is several kilobits if the distortion of the optical disk is measured and stored at 1 mm intervals in the radial direction, and several megabits can be realized if it is measured for each track.

[0017]

[Effects of the Invention] As described above , according to the present invention,
Stores the runout information specific to the optical disk that has been measured in advance.
Is mounted in a detachable manner.
Reading means for reading the information at any time, and the optical head
It operates after receiving a seek command to move to the target track,
The reading means is used to move forward from the surface runout information storage medium.
Read out the runout information on the target track,
When the optical head moves to the target track,
Control means to apply attitude servo based on information
To store the runout pattern of each optical disc in advance.
Light to an optical disk using an information storage medium
Head drive can be controlled, and runout information can be recorded.
A storage medium corresponds one-to-one to a specific optical disc
Prepared as a dedicated medium, and for reading means
Because it is detachably mounted, it can be used for recording and playback of optical discs.
Attach the surface runout information storage medium to the reading means
Alone provides the runout information specific to the optical disc,
Each time the optical disk is recorded and reproduced,
There is no trouble of collecting the
Can be obtained simply and accurately, and
Not only in the circumferential direction but also in the radial direction
Allows the head to accurately follow and read / write accurate information
And so on .

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of an optical disk device of the present invention .

2 is a diagram illustrating the operation of the optical head on the optical disc shown in FIG.

FIG. 3 is a view showing a state of surface deflection of an optical disk.

FIG. 4 is a diagram for explaining in detail the operation of the optical head on the optical disk shown in FIG. 2;

5 is a diagram illustrating the measurement of the surface vibration pattern of an optical disk shown in FIG.

FIG. 6 is a flowchart illustrating a method of controlling the optical head shown in FIG. 1;

FIG. 7 is a diagram for explaining the operation of the optical head shown in FIG.

FIG. 8 is a diagram illustrating the tracking characteristics of the optical head shown in FIG.

FIG. 9 is a side view of a conventional example.

FIG. 10 is a top view of a conventional example.

11 is a graph showing changes in skew of the optical disk radial direction shown in FIG. 10.

FIG. 12 is a diagram illustrating the tracking characteristics of the optical head shown in FIGS. 9 and 10;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical disk apparatus 2 Optical disk 3 Spindle motor 4 Optical head 5 Read-out means (storage part) 6 Operation part 7 Control part 8 Surface runout information storage medium

Claims (1)

(57) [Scope of request for utility model registration] An optical head rotates a rotating optical disk in a radial direction.
Optical disk drive that reads and writes information by scanning in the
To record the runout information specific to the optical disk that has been measured in advance.
The recognizable surface deflection information storage medium is detachably mounted, and
Reading means for reading out surface run-out information at any time;
Operates after receiving a seek command to move the track to the target track
The reading means is used to determine whether the surface deviation information storage medium is used.
Read out the runout information on the target track from
When the optical head moves to the target track,
Control means for applying a posture servo based on shake information
An optical disc device characterized by performing: