JP2006004533A - Tilt correcting method and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilt correcting method and an optical disk device with which recording quality and reproducing quality are improved. <P>SOLUTION: Since a tilt correction value is obtained for each recording speed of an optical disk 101, even when recording speed for each optical disk 101 is varied, the optical disk device can cope with the variation, accuracy of the tilt correction value is improved, and recording quality and reproducing quality can be improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tilt correction method and an optical disc apparatus.

  2. Description of the Related Art An optical disc apparatus that records and reproduces data by focusing laser light for recording and reproduction on an optical disc track using an objective lens has been developed. The objective lens used in this optical disc apparatus is for condensing laser light to form a minute light spot. When the optical axis is tilted with respect to the optical disc, aberration occurs in the light spot, and recording / reproduction is performed. May cause trouble. The inclination of the objective lens with respect to the recording surface of the optical disk must be minimized.

In recent years, optical disc drives have been increased in density, and for this purpose, an apparatus provided with a mechanism for compensating for tilt (hereinafter referred to as “tilt”) between the information recording medium and the optical system, which is a factor that increases aberration of the optical system. Has increased.
In the prior art, a tilt sensor using a light emitting element, a two-part light receiving element that receives reflected light reflected by an optical disc, and tilt correction of the optical pickup is tilted based on the output of the tilt sensor. A device has been proposed. Such a tilt sensor is initially adjusted in position so that there is no difference in the output of the two-divided light receiving element with respect to an optical disk without tilt, and the tilt sensor is reflected by the light emitted from the light emitting element reflected by the optical disk. To make a spot on the tilt sensor. The tilt is detected by taking the difference signal of the reflected light spot.

As described above, the tilt between the optical disc and the optical pickup is detected, and as a method of correcting the tilt, a tilt adjustment value that maximizes the reproduction signal amplitude at several points on the optical disc is acquired in advance. There are a method of performing tilt control based on this data and a method of always obtaining the tilt of the optical disk and performing tilt servo using a tilt sensor. That is, this technique calculates a tilt adjustment value in consideration of the number of rotations of the optical disk (see, for example, Patent Document 1).
JP 2002-092917 A

By the way, in the conventional technique described above, the tilt adjustment value is not obtained for each recording speed. For this reason, highly accurate tilt correction is not performed. Further, it is conceivable that the tilt of the recording surface of the optical disc varies depending on the recording speed, and the tilt adjustment values for the low speed and the high speed cannot be used in common. As a result, there is a concern that the recording quality and the reproduction quality are degraded.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tilt correction method and an optical disc apparatus that solve the above-described problems and improve recording quality and reproduction quality.

  In order to solve the above-mentioned problems, according to the first aspect of the present invention, the optical pickup is moved in the radial direction of the optical disk before the laser beam is focused on the optical disk by the objective lens of the optical pickup and recording / reproduction is performed. In the tilt correction method for detecting the relative tilt between the optical pickup and the optical disc and adjusting the relative tilt with respect to the optical disc by adjusting at least the tilt of the objective lens, for each recording speed of the optical disc. The tilt adjustment value is obtained.

  According to the first aspect of the present invention, since the tilt correction value is obtained for each recording speed of the optical disc, it is possible to cope with fluctuations in the recording speed for each optical disc, the accuracy of the tilt correction value is improved, and recording is performed. Quality and reproduction quality can be improved.

  According to a second aspect of the present invention, in the tilt correction method according to the first aspect, a tilt correction value at the recording speed is obtained immediately before data is recorded on the optical disc.

  According to the second aspect of the present invention, more accurate tilt correction is obtained by obtaining the correction value every time immediately before recording for each optical disc. As a result, improvement in recording quality and reproduction quality can be realized.

  According to a third aspect of the present invention, in the tilt correction method according to the second aspect, when the tilt correction value at the recording speed is obtained immediately before data is recorded on the optical disk, the disk ID and the tilt correction value are stored. In addition, when data is recorded on an optical disc having the disc ID thereafter, tilt control is performed using the stored tilt correction value.

  According to the third aspect of the present invention, the correction value is obtained immediately before recording data on the optical disc, that is, the tilt correction value obtained and stored once is used for the second and subsequent recordings. The subsequent recording time can be shortened.

  According to a fourth aspect of the present invention, in the tilt correction method according to the first aspect, it is determined whether or not the tilt correction is performed depending on the type of the optical disc.

  There are CDs, DVDs, and the like as optical disks. Among them, there are optical disks that have little effect of improving recording quality and reproduction quality even when tilt control is performed. According to the fourth aspect of the present invention, it is possible to shorten the recording time and the reproduction time by discriminating such an optical disc at the time of mounting (when putting it in a predetermined position in the optical disc apparatus) and not performing the tilt control. Can do.

According to a fifth aspect of the present invention, in the tilt correction method according to the first aspect, a tilt correction value at the recording speed is obtained immediately before data is recorded on the optical disc, and the tilt correction value exceeds a predetermined range. In such a case, recording is not performed at the recording speed.
According to the fifth aspect of the present invention, when the tilt correction value for obtaining the optimum recording quality and reproduction quality exceeds the tilt driving range, the recording quality is not implemented at the recording speed. , Can prevent degradation of playback quality.

  According to a sixth aspect of the present invention, in the tilt correction method according to the fifth aspect, the tilt correction values are obtained at a plurality of recording speeds immediately before data is recorded on the optical disc.

  According to the sixth aspect of the present invention, it is possible to determine at which recording speed the optimum tilt control is possible by acquiring tilt correction values at a plurality of recording speeds immediately before recording. In addition, in an apparatus for recording and reproducing an optical disc, when tilt control is impossible at a recording speed designated by the user, it is possible to follow up such as recording at another recording speed instead.

  The effect of Claims 4-6 is the same as the effect of Claims 1-3, respectively, The effect of Claims 7-12 is the same as the effect of Claims 4-6, respectively.

  According to a seventh aspect of the present invention, there is provided an optical pickup provided with an objective lens for condensing laser light for recording / reproducing on an optical disc, driving means for moving the optical pickup in a radial direction of the optical disc, and the optical pickup. A tilt detection unit that detects a relative tilt between the optical pickup and the optical disc, and a tilt correction unit that adjusts the tilt of the objective lens and corrects the relative tilt between the optical disc and the optical pickup; In the optical disk apparatus, the correction means obtains a tilt correction value for each recording speed of data on the optical disk.

  According to an eighth aspect of the present invention, there is provided an optical pickup provided with an objective lens for condensing a laser beam for recording / reproducing on an optical disc, driving means for moving the optical pickup in a radial direction of the optical disc, and the optical pickup. A tilt detection unit that detects a relative tilt between the optical pickup and the optical disc, and a tilt correction unit that adjusts the tilt of the objective lens and corrects the relative tilt between the optical disc and the optical pickup; In the optical disk apparatus, the tilt correction means obtains a tilt correction value at the recording speed immediately before recording data on the optical disk.

  According to a ninth aspect of the present invention, there is provided an optical pickup provided with an objective lens for condensing a laser beam for recording / reproducing on an optical disc, driving means for moving the optical pickup in a radial direction of the optical disc, and mounted on the optical pickup. An apparatus comprising: a tilt detecting unit that detects a relative tilt between the optical pickup and the optical disc; and a tilt correcting unit that corrects the relative tilt with respect to the optical disc by adjusting at least the tilt of the objective lens. The tilt correction means includes storage means for storing a correction value obtained for each recording speed.

  According to a tenth aspect of the present invention, there is provided an optical pickup provided with an objective lens for condensing a laser beam for recording / reproducing on an optical disc, driving means for moving the optical pickup in a radial direction of the optical disc, and the optical pickup. A tilt detector for detecting a relative tilt between the optical pickup and the optical disc mounted thereon, and at least adjusting the tilt of the objective lens to correct the relative tilt with the optical disc, and tilt correction at each recording speed In the optical disk apparatus having a tilt correction means for obtaining a value, the tilt correction means determines whether to perform tilt correction according to the type of the optical disk.

  According to an eleventh aspect of the present invention, there is provided an optical pickup provided with an objective lens for condensing a laser beam for recording / reproducing on an optical disc, driving means for moving the optical pickup in a radial direction of the optical disc, and the optical pickup. A tilt detector for detecting a relative tilt between the optical pickup and the optical disc mounted thereon, and at least adjusting the tilt of the objective lens to correct the relative tilt with the optical disc, and tilt correction at each recording speed In the optical disc apparatus having a tilt correction means for obtaining a value, the tilt correction means obtains a tilt correction value at the recording speed immediately before recording data on the optical disc, and the tilt correction value exceeds a predetermined range. In such a case, recording is not performed at the recording speed.

  According to a twelfth aspect of the present invention, in the optical disk device according to the eleventh aspect, the tilt correction means acquires tilt correction values at a plurality of recording speeds immediately before recording data on the optical disk. To do.

  Since the tilt correction value is obtained for each recording speed of the optical disc, the accuracy of the tilt correction value is improved, and the recording quality and the reproduction quality can be improved.

Embodiments of the present invention will be described in detail.
(Constitution)
FIG. 1 is a diagram showing an embodiment of an optical disc apparatus to which the tilt correction method of the present invention is applied.
This figure is also a diagram showing a configuration of a tilt compensation mechanism for realizing the tilt correction method of claims 1 to 6.
In FIG. 1, an optical disk (101) is rotationally driven around a central axis P (in the direction of arrow (120)) by a spindle motor (102). The optical pickup (111) is supported so as to be movable in the radial direction of the optical disc (101), and a tilt sensor (104) is attached thereto. The tilt coil (103) is attached to an optical pickup (111), and an objective lens (for example, a biconvex lens, a plano-convex lens, a convex lens) that collects and emits laser light from a laser light source (for example, a laser diode, not shown). The inclination of the meniscus lens (not shown) with respect to the optical disc (101) is driven.

The tilt sensor (104) is a sensor including a light emitting element (for example, a light emitting diode or a laser diode) and a two-divided light receiving element (for example, a photodiode or a phototransistor). The tilt sensor (104) irradiates light to the detection target and receives the reflected light. When the spot of the reflected light is not inclined on the optical disc (101), the tilt sensor (104) If the optical disc (101) is inclined when it falls on the dividing line of the light receiving element divided into two, the light receiving element deviates from the dividing line and hits one of the light receiving elements. By detecting an electrical signal from the light receiving element, the presence or absence of the tilt of the detection target can be known. By using the tilt sensor (104) in this way, a signal corresponding to the tilt amount of the optical disc (101) can be obtained.
The reproduction signal is obtained from the photo detector (105), and the reproduction signal amplitude can be acquired. Reference numeral 106 denotes an RFamp (high frequency amplifier circuit).

Tilt control is performed by a signal from the CPU (108). A control signal is sent from the CPU (108) to the tilt coil (103) via the servo control circuit (107), and the angle between the objective lens and the optical disc (101) is controlled to be optimum. A known technique can be applied to the tilt coil (103) (see, for example, Japanese Patent Application Laid-Open No. 2003-272204, paragraphs “0024” and “0025”).
For tilt correction, a tilt adjustment value that maximizes the reproduction signal and TE (track error) signal at several points on the optical disc (101) is acquired in advance, and the tilt correction value is stored in the memory (110). There are two methods: a method of performing tilt control based on this data, and a method of performing tilt servo by always obtaining the tilt of the optical disc (101) using the tilt sensor (104). The present invention can be implemented by both of these methods. A known technique can be applied to the tilt sensor (104) (see, for example, JP-A-2003-272204, paragraph "0003").
Here, the tilt drive amount, the tilt adjustment value, and the tilt correction value in this specification are defined as follows.
“Tilt drive amount”: Tilt drive amount “Tilt adjustment value”: difference between the tilt drive amount T2 and the tilt drive amount T1, which is a numerical value obtained by calculation and stored in a memory.
“Tilt correction value”: the sum of the tilt drive amount T1 ′ and the tilt control value T, which is obtained by calculation, and is driven by that value to perform tilt control.
In the embodiment described below, a method of acquiring a tilt adjustment value that maximizes the reproduction signal and the TE signal is shown.

(Function)
The method of claim 1 will be described by taking the operation flow of FIGS. 1 and 2 as an example.
FIG. 2 is a diagram showing an operation flow of the optical disc apparatus shown in FIG.
The following example of the operation flow is generally performed in the manufacturing process of the optical disc apparatus.
First, an unrecorded disc (raw optical disc: 101: see FIG. 1) is placed in a predetermined position (position shown in FIG. 1) of the optical disc apparatus (step 202), and the rotation speed of the raw optical disc (101) is set (step 202). Step 203).
Next, the raw optical disk (101) is rotated at a recording speed set by a spindle motor (102: see FIG. 1). With the raw optical disk (101) rotated, the optical pickup (111: see FIG. 1) is moved (driven) from a predetermined lower limit to an upper limit with a tilt coil (103: see FIG. 1). The amplitude (tilt drive amount) of the TE signal obtained from the photodetector (105: see FIG. 1) is measured, and a tilt drive amount T1 that maximizes TE is obtained (step 204).
Next, a recorded disc (recorded optical disc) is placed in a predetermined position in the optical disc apparatus (step 205), and the recorded optical disc (101) is rotated by the spindle motor (102) at the speed set in step 202.
The recorded optical disk (101) is kept rotated, and the amplitude of the reproduction signal obtained from the photodetector (105) while the optical pickup (111) is moved from the lower limit to the upper limit determined in advance by the tilt coil (103). (Tilt drive amount) is measured, and a tilt drive amount T2 that maximizes TE is obtained (step 206).
Then, a tilt adjustment value T, which is the difference between the tilt drive amounts T1 and T2, is calculated (step 207).
The above operation is performed for each speed, and the tilt adjustment value T calculated for each speed is stored in a memory (110: see FIG. 1).
As a result, by obtaining a tilt correction value for each speed, highly accurate tilt correction can be performed, and recording quality and reproduction quality can be improved.
The above is the operation example of claim 1.

Next, the method of claim 2 will be described by taking the operation flow of FIGS. 1 and 3 as an example.
FIG. 3 is a diagram showing another operation flow of the optical disc apparatus shown in FIG.
First, an optical disc to be recorded (101: see FIG. 1) is placed in a predetermined position (position shown in FIG. 1) in the optical disc apparatus (step 302), and a recording speed is set (step 303).
Next, the optical disk (101) is rotated around the central axis P at the recording speed by a spindle motor (102: see FIG. 1). The optical disc (101) is kept in a rotated state, and the optical pickup (111: see FIG. 1) is moved from the lower limit to the upper limit determined in advance by the tilt coil (103: see FIG. 1). The amplitude (tilt drive amount) of the obtained TE signal is measured, and a tilt drive amount T1 ′ that maximizes TE is obtained (step 304).
Next, the correction value T corresponding to the recording speed is called from the memory (110), and the correction value T is added to the tilt drive amount T1 ′ to calculate the tilt correction value T2 ′ that maximizes the reproduction signal amplitude. (Step 305).
Then, tilt control is performed with the tilt correction value T2 ′, and data is recorded on the optical disc (101). As a result, the accuracy of the tilt correction value is improved, and the recording quality and reproduction quality can be improved.

(effect)
The present embodiment is characterized in that a correction value is obtained immediately before data is recorded on an optical disc as a time when the tilt correction method of claim 1 is performed. There are a number of possible timings for obtaining the correction value, but considering variations in the shape of each optical disc, tilt correction can be performed with higher accuracy by obtaining the correction value every time immediately before recording for each optical disc. By this method, it is possible to improve recording quality and reproduction quality.
The above is the operation example of claim 2.

(Function)
Next, the method of claim 3 will be described by taking the operation flow of FIGS. 1 and 4 as an example.
FIG. 4 is a diagram showing another operation flow of the optical disk apparatus shown in FIG.
First, the optical disc (101) to be recorded is placed in a predetermined position in the optical disc apparatus (step 402), and the recording speed is set (step 403).
Next, the optical disk (101) is rotated around the central axis P by the spindle motor (102). The speed at this time may not be the same as the recording speed.
Here, the tilt drive amount is set to the initial value T0. This setting is a setting for reproducing the optical disc (101) with the highest quality in a state where the tilt is not adjusted.
Next, the disk ID (Identification) of the optical disk (101) is played back (step 405), and the disk ID can be played back (step 406 / No), and the disk ID is stored in the memory (110: see FIG. 1). ) Is recorded (step 407 / Yes), the tilt correction value T2 ′ stored in the memory (110) is employed (step 410).

If the disc ID cannot be reproduced (step 406 / Yes), or if the reproduced disc ID is not stored in the memory (110) (step 407 / No), the optical disc (101) is recorded at the recording speed. Measure the amplitude (tilt drive amount) of the TE signal obtained from the photodetector (105) while moving (driving) from a predetermined lower limit to an upper limit with a tilt coil (103: see FIG. 1). A tilt drive amount T1 ′ that maximizes TE is obtained (step 408), a tilt adjustment value T corresponding to the recording speed is called from the memory (110), and the tilt adjustment value T is added to the tilt drive amount T1 ′. Thus, a tilt correction value T2 ′ is calculated so that the reproduction signal amplitude is maximized (step 409).
Then, tilt control is performed with the tilt adjustment value T2 ′, and data is recorded on the optical disc (101).

(effect)
In the present embodiment, the correction value is obtained immediately before data is recorded on the optical disc as the time when the tilt correction method of claim 1 is performed. By using the tilt correction value obtained and stored once for the second and subsequent recordings, the recording time for the second and subsequent times can be reduced. The disc ID is information unique to the optical disc recorded on the optical disc, and the recording area is provided at a location different from the data recording area. In claim 3, this disk ID is used as a disk unique information value. As a result, the accuracy of the tilt correction value is improved, and the recording quality and reproduction quality can be improved.
The above is the operation example of claim 3.

  By the way, in the optical disc manufacturing process, the tilt drive amount that maximizes the amplitude of the TE signal when an unrecorded optical disc is mounted and the tilt drive amount that maximizes the reproduction signal amplitude when reproducing the recorded optical disc are measured. The difference between the two tilt drive amounts is stored in the memory as a tilt adjustment value, and the tilt drive amount at which the TE signal amplitude is maximized when an optical disc to be recorded or reproduced is mounted during actual use (when used by a user) is measured. In a tilt control method in which a value obtained by adding the tilt adjustment value to the measured amount (tilt correction value) is set as a tilt drive amount and recording or reproduction is performed, a tilt correction value is not obtained for each recording speed.

For this reason, the inclination of the recording surface of the optical disc may vary depending on the recording speed, and it is conceivable that the low-speed tilt correction value and the high-speed tilt correction value cannot be used in common.
However, obtaining the tilt correction value produces an effect of improving the recording quality and the reproduction quality, but also causes a problem of extending the recording time and the reproduction time. Therefore, it is necessary to take measures to shorten the recording time and the reproduction time as much as possible.

Therefore, the present inventor has proposed a tilt correction method and an optical disc apparatus in which recording time and reproduction time are shortened, and will be described below.
The configuration of the tilt compensation mechanism for realizing the tilt correction method of claims 4 to 6 is the same as that of FIG.
For tilt correction, a tilt correction value that maximizes the reproduction signal and TE signal at several points on the optical disc (101) is acquired in advance and stored in the memory (110), and the tilt is corrected based on this data. There are a control method and a tilt sensor (104) to always obtain the tilt of the optical disk (101) and perform tilt servo. The present invention can be implemented by both of these methods. In the embodiment described below, a method of acquiring a tilt correction value that maximizes the reproduction signal and the TE signal is shown.
Next, the method of claim 4 will be described by taking the operation flow of FIGS. 1, 5, and 6 as an example.

(Function)
The operation flow of FIG. 5 will be described. This is generally performed in the manufacturing process of the optical disk device.
First, an unrecorded optical disc (101: see FIG. 1) is placed in a predetermined position in the optical disc apparatus (step 502), and the speed is set (step 503).
Next, the optical disk (101) is rotated around the central axis P at that speed by a spindle motor (102: see FIG. 1). Obtained from the photodetector (105: see FIG. 1) while the optical disk (101) is rotated and moved (driven) from a predetermined lower limit to an upper limit by the tilt coil (103: see FIG. 1). The amplitude of the TE signal is measured, and a tilt drive amount T1 that maximizes TE is obtained (step 504: see FIG. 1).

Next, the recorded optical disk (101) is inserted (205), and the optical disk (101) is rotated at the speed set in step 502 by the spindle motor (102). The amplitude of the reproduction signal obtained from the photodetector (105: see FIG. 1) while keeping the optical disk (101) rotated and moving (driving) the tilt coil (103) from a predetermined lower limit to an upper limit. And a tilt drive amount T2 that maximizes TE is obtained (step 506).
Then, a tilt adjustment value T that is a difference between the tilt drive amounts T1 and T2 is calculated (step 507).
The above operation is performed for each speed, and the tilt adjustment value T calculated for each speed is stored in a memory (110: see FIG. 1).

Next, the operation when the user records / reproduces the optical disc (101) will be described based on the operation flow of FIG.
FIG. 6 is a diagram showing another operation flow of the optical disc apparatus shown in FIG.
First, the optical disc (101) to be recorded is placed in a predetermined position in the optical disc apparatus (step 602).

Next, the type of the optical disk (101) is detected from the amount of reflected light of the laser emitted from the optical pickup (111: see FIG. 1), and it is determined whether or not the optical disk (101) requires tilt control (step 603). ).
If it is determined that tilt control is necessary (step 603 / Yes), a recording speed is set (step 604), and the recording speed of the optical disc (101) is set by the spindle motor (102: see FIG. 1). Rotate with Obtained from the photodetector (105: see FIG. 1) while the optical disk (101) is rotated and moved (driven) from a predetermined lower limit to an upper limit by the tilt coil (103: see FIG. 1). The amplitude of the TE signal is measured, and a tilt drive amount T1 ′ that maximizes TE is obtained (step 605).

Next, an adjustment value T corresponding to the recording speed is called from the memory (110: see FIG. 1), and a tilt correction value T2 ′ that maximizes the reproduction signal amplitude is obtained by adding the value to the tilt drive amount T1 ′. Calculate (step 606).
Then, the tilt drive is controlled by the tilt correction value T2 ′, and data is recorded on the optical disc (101) (step 607).
If it is determined in step 603 that tilt control is unnecessary (step 603 / No), the recording speed is set (step 608), and then the optical disc (101) is not subjected to tilt control. Data is recorded (step S609).

(effect)
There are various types of optical discs such as CD (compact disc) and DVD (digital video disc). Among them, there are optical discs that have little effect of improving recording quality and reproduction quality even when tilt control is performed. By discriminating such an optical disc at the time of mounting and not performing tilt control, the recording time and the reproduction time can be shortened.
The above is the operation example of claim 4.

(Function)
Next, the method of claim 5 will be described with reference to FIG. 1 and the operation flows of FIG. 2 and FIG.
FIG. 7 is a view showing another operation flow of the optical disc apparatus shown in FIG.
The operation flow of FIG. 2 is as described above.
Next, the operation when the user records / reproduces data on / from the optical disc will be described based on the operation flow of FIG.
First, an optical disk to be recorded (101: see FIG. 1) is placed in a predetermined position in the optical disk apparatus (step 702).
Then, the recording speed is set (step 703), and the optical disk (101) is rotated at the recording speed by the spindle motor (102: see FIG. 1). Obtained from the photodetector (105: see FIG. 1) while the optical disk (101) is rotated and moved (driven) from a predetermined lower limit to an upper limit by the tilt coil (103: see FIG. 1). The amplitude (tilt drive amount) of the TE signal is measured, and a tilt drive amount T1 ′ that maximizes TE is obtained (step 704).

Next, an adjustment value T corresponding to the recording speed is called from the memory (110: see FIG. 1), and a tilt correction value T2 ′ that maximizes the reproduction signal amplitude is obtained by adding the value to the tilt drive amount T1 ′. Calculate (step 705).
Then, it is determined whether or not the tilt correction value T2 ′ is within the tilt drive range (step 706).
Here, if the tilt correction value T2 ′ is within the tilt drive range (step 706 / Yes), the tilt drive is controlled by the tilt correction value T2 ′, and data is recorded on the optical disc (101) (step 707). If it is not within the tilt drive range (step 706 / No), data is not recorded (step 708), and the process ends.
Here, the tilt drive range may be stored in the memory in advance during the manufacturing process or the design process. Further, the criterion for determination here may be set in a range narrower than the actual tilt drive range.

(effect)
When the tilt correction value that can obtain the optimum recording quality and reproduction quality exceeds the tilt drive range, the recording quality and reproduction quality can be prevented from deteriorating by not performing recording and reproduction at that recording speed. .
The above is the operation example of claim 5.

(Function)
Next, the method of claim 6 will be described with reference to FIG. 1, and the operation flows of FIGS.
FIG. 8 is a diagram showing another operation flow of the optical disc apparatus shown in FIG.
The operation flow of FIG. 5 is as described above.
Next, the operation when the user records and reproduces the optical disc (101: see FIG. 1) will be described based on the operation flow of FIG.
First, the optical disc (101) to be recorded is placed in a predetermined position in the optical disc apparatus (step 802).
Then, the recording speed is set (step 803), and the optical disk (101) is rotated around the central axis P at the recording speed by the spindle motor (102). Obtained from the photodetector (105: see FIG. 1) while the optical disk (101) is rotated and moved (driven) from a predetermined lower limit to an upper limit by the tilt coil (103: see FIG. 1). The amplitude of the TE signal is measured, and a tilt drive amount T1 ′ that maximizes TE is obtained (step 804).

Next, an adjustment value T corresponding to the recording speed is called from the memory (110: see FIG. 1), and a tilt correction value T2 ′ that maximizes the reproduction signal amplitude is obtained by adding the value to the tilt drive amount T1 ′. Calculate (step 805).
Then, it is determined whether or not the tilt correction value T2 ′ is within the tilt drive range (step 806).
Here, if the tilt correction value T2 ′ is within the tilt drive range (step 806 / Yes), the tilt drive is controlled by the tilt correction value T2 ′, and data is recorded on the optical disc (step 807).
If it is not within the tilt drive range (step 806 / No), it is determined whether the currently set recording speed is the lowest recordable speed (step 808).
Here, if the currently set recording speed is not the lowest speed (step 808 / No), the recording speed is set lower than the current setting (step 809), and the tilt drive amount T1 is such that TE is maximized again. 'Is obtained (step 804), a tilt correction value T2' is calculated (step 805), and it is determined whether the tilt correction value T2 'is within the tilt drive range (step 806). If it is determined in step 808 that the currently set recording speed is the lowest recordable speed (step 808 / Yes), the process ends without recording data (step 808).

(effect)
By acquiring tilt correction values at a plurality of recording speeds immediately before recording, it is possible to determine at which recording speed optimum tilt control is possible. In addition, in an apparatus for recording / reproducing an optical disc, when tilt control is impossible at a recording speed designated by the user, follow-up such as recording at another recording speed instead becomes possible.
The above is the operation example of claim 6.
The structure of the apparatus of Claims 7-12 is the same as that of the said description based on FIG. The operation flows of claims 4 to 6 are the same as the operation flows of claims 1 to 3, respectively. The operation flows of claims 7 to 12 are the same as the operation flows of claims 4 to 6, respectively.

It is a figure which shows one Embodiment of the optical disk apparatus to which the tilt correction method of this invention is applied. FIG. 2 is a diagram showing an operation flow of the optical disc apparatus shown in FIG. 1. FIG. 10 is a diagram showing another operation flow of the optical disc apparatus shown in FIG. 1. FIG. 10 is a diagram showing another operation flow of the optical disc apparatus shown in FIG. 1. It is a figure which shows the operation | movement flow of a general optical disk apparatus. FIG. 10 is a diagram showing another operation flow of the optical disc apparatus shown in FIG. 1. FIG. 10 is a diagram showing another operation flow of the optical disc apparatus shown in FIG. 1. FIG. 10 is a diagram showing another operation flow of the optical disc apparatus shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Optical disk 102 Spindle motor 103 Tilt coil 104 Tilt sensor 105 Photo detector 106 RFamp
107 Servo control circuit 108 CPU
109 Motor driver 110 Memory

Claims (12)

Before performing recording and reproduction by focusing the laser beam on the optical disc with the objective lens of the optical pickup,
Moving the optical pickup in the radial direction of the optical disc;
Detecting a relative tilt between the optical pickup and the optical disc;
In a tilt correction method for correcting a relative tilt with respect to the optical disc by adjusting at least the tilt of the objective lens,
A tilt correction method, wherein a tilt adjustment value is obtained for each recording speed of the optical disc. The tilt correction method according to claim 1,
A tilt correction method for obtaining a tilt correction value at a recording speed immediately before recording data on the optical disc. The tilt correction method according to claim 2,
When the tilt correction value at the recording speed is obtained immediately before data is recorded on the optical disc, the disc ID and tilt correction value are stored, and thereafter data is recorded on the optical disc having the disc ID. A tilt correction method, wherein tilt control is performed using a stored tilt correction value. The tilt correction method according to claim 1,
A tilt correction method for determining whether to perform tilt correction according to the type of the optical disc. The tilt correction method according to claim 1,
A tilt correction method for obtaining a tilt correction value at the recording speed immediately before recording data on the optical disc and not recording at the recording speed if the tilt correction value exceeds a predetermined range. . The tilt correction method according to claim 5, wherein
A tilt correction method comprising: acquiring tilt correction values at a plurality of recording speeds immediately before recording data on the optical disc. An optical pickup provided with an objective lens for condensing laser light for recording / reproducing on an optical disc;
Driving means for moving the optical pickup in the radial direction of the optical disc;
A tilt detecting means mounted on the optical pickup for detecting a relative tilt between the optical pickup and the optical disc;
In an optical disc apparatus comprising at least a tilt correction unit that adjusts a tilt of the objective lens to correct a relative tilt with the optical disc,
An optical disc apparatus characterized in that the correction means obtains a tilt correction value for each recording speed of data on the optical disc. An optical pickup provided with an objective lens for condensing laser light for recording / reproducing on an optical disc;
Driving means for moving the optical pickup in the radial direction of the optical disc;
A tilt detecting means mounted on the optical pickup for detecting a relative tilt between the optical pickup and the optical disc;
In an optical disc apparatus comprising at least a tilt correction unit that adjusts a tilt of the objective lens to correct a relative tilt with the optical disc,
The optical disc apparatus characterized in that the tilt correction means obtains a tilt correction value at the recording speed immediately before recording data on the optical disc. An optical pickup provided with an objective lens for condensing laser light for recording / reproducing on an optical disc;
Drive means for moving the optical pickup in the radial direction of the optical disc;
A tilt detecting means mounted on the optical pickup for detecting a relative tilt between the optical pickup and the optical disc;
In a device including at least a tilt correction unit that adjusts a tilt of the objective lens to correct a relative tilt with the optical disc,
An optical disc apparatus comprising a storage means for storing a correction value obtained by the tilt correction means for each recording speed. An optical pickup provided with an objective lens for condensing laser light for recording / reproducing on an optical disc;
Driving means for moving the optical pickup in the radial direction of the optical disc;
A tilt detecting means mounted on the optical pickup for detecting a relative tilt between the optical pickup and the optical disc;
In an optical disc apparatus having a tilt correction unit that adjusts at least the tilt of the objective lens to correct a relative tilt with the optical disc and obtains a tilt correction value for each recording speed,
The optical disc apparatus characterized in that the tilt correction means determines whether or not to perform tilt correction according to the type of the optical disc. An optical pickup provided with an objective lens for condensing laser light for recording / reproducing on an optical disc;
Driving means for moving the optical pickup in the radial direction of the optical disc;
A tilt detecting means mounted on the optical pickup for detecting a relative tilt between the optical pickup and the optical disc;
In an optical disc apparatus having a tilt correction unit that adjusts at least the tilt of the objective lens to correct a relative tilt with the optical disc and obtains a tilt correction value for each recording speed,
The tilt correction means obtains a tilt correction value at the recording speed immediately before recording data on the optical disc, and does not record at the recording speed when the tilt correction value exceeds a predetermined range. An optical disc apparatus characterized by that. The optical disc apparatus according to claim 11, wherein
The optical disc apparatus characterized in that the tilt correction means acquires tilt correction values at a plurality of recording speeds immediately before recording data on the optical disc.

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