KR20100060798A - Optical disc device and focus balance adjust method - Google Patents

Optical disc device and focus balance adjust method Download PDF

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Publication number
KR20100060798A
KR20100060798A KR1020080119544A KR20080119544A KR20100060798A KR 20100060798 A KR20100060798 A KR 20100060798A KR 1020080119544 A KR1020080119544 A KR 1020080119544A KR 20080119544 A KR20080119544 A KR 20080119544A KR 20100060798 A KR20100060798 A KR 20100060798A
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KR
South Korea
Prior art keywords
focus balance
adjustment value
balance adjustment
focus
value
Prior art date
Application number
KR1020080119544A
Other languages
Korean (ko)
Inventor
이승철
Original Assignee
주식회사 히타치엘지 데이터 스토리지 코리아
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Priority to KR1020080119544A priority Critical patent/KR20100060798A/en
Publication of KR20100060798A publication Critical patent/KR20100060798A/en

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0908—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for focusing only
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0925—Electromechanical actuators for lens positioning
    • G11B7/0933—Details of stationary parts
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0925—Electromechanical actuators for lens positioning
    • G11B7/0935—Details of the moving parts
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1372—Lenses
    • G11B7/1374—Objective lenses
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1372—Lenses
    • G11B7/1378—Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00—Record carriers by type
    • G11B2220/20—Disc-shaped record carriers
    • G11B2220/25—Disc-shaped record carriers characterised in that the disc is based on a specific recording technology
    • G11B2220/2537—Optical discs

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device and a focus balance adjustment method. For example, in an optical disc device such as a BD-Recorder, a reference adjustment range for adjusting the focus balance, a high limit, and a low A reference value of a low limit is stored in advance, and a focus balance adjustment value for an optical disc is detected, compared with the reference value, and the detected focus balance adjustment value is determined according to the comparison result. By changing to the reference value of the limit or low limit, or poorly processing due to the focus failure, the focus balance adjustment value for the optical disc such as BD-R / RE, which has a narrow movable range (WD) of the objective lens and generates a lot of spherical aberration, etc. To prevent the optical disk and the objective lens from colliding with each other and to effectively prevent the failure of the focus servo operation. Thereby banghal.

Description

Optical disc device and focus balance adjust method}

The present invention relates to an optical disc device and a focus balance adjustment method for optimizing a focus balance adjustment value for an optical disc such as a BD-R / RE or the like in which the movable range WD of the objective lens is narrow and a lot of spherical aberration occurs.

Generally used optical discs include CD (CD) series, DVD (DVD) series, HD DVD (HD DVD) series, and BD (BD) series optical discs, for example, as shown in FIG. Similarly, in the CD-R / RW, a data recording layer is formed at a position separated by 1.2 mm from the cover layer, and a numerical aperture NA of 0.45 and a red laser having a wavelength of 780 nm are used.

In the DVD +/- R / RW, the data recording layer is formed at a position 0.6 mm away from the cover layer, and the numerical aperture NA of the objective lens is 0.60 and a red laser having a wavelength of 650 nm is used, and the HD DVD-R / In the RW, the data recording layer is formed at a position 0.6 mm away from the cover layer, and a blue laser having a numerical aperture NA of 0.60 and a wavelength of 405 nm is used.

On the other hand, in the BD-R / RE, the data recording layer is formed at a position 0.1 mm away from the cover layer, and a blue laser having a numerical aperture NA of 0.85 and a wavelength of 405 nm is used. For example, as shown in FIG. 2, the / RE has a working distance (WD) in which an object lens can move without colliding with the cover layer of the optical disk, and other types of optical disks. Since it is relatively narrow compared with, the optical disk and the objective lens are likely to collide with each other.

In addition, since BD-R / RE uses an objective lens having a wide numerical aperture (NA = 0.85), as shown in FIG. 3, for example, spherical aberration compared to other types of optical disks. Since many occur, accurate control of the focus servo operation is required.

According to the present invention, when the focus servo operation is performed on an optical disk such as a BD-R / RE having a narrow movable range WD and a large spherical aberration, the focus balance adjustment value is optimized. The present invention provides an optical disk device and a focus balance adjusting method for preventing an optical disk and an objective lens from colliding with each other and preventing failure of a focus servo operation.

A focus balance adjusting method in an optical disk device according to the present invention comprises the steps of: previously storing a reference value for adjusting the focus balance; Detecting a focus balance adjustment value for the optical disc and comparing the result with the reference value; And changing the detected focus balance adjustment value to an arbitrary value according to the result of the comparison, or performing three-step failure processing due to a focus failure.

The reference value may be separately stored as a focus balance reference adjustment range, a high limit, and a low limit, respectively.

The specific value may be any one of a focus balance adjustment value stored at the high limit or a focus balance adjustment value stored at the low limit.

In addition, the step 3 may include: if the difference value between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored as the high limit or the low limit is small, To change the focus balance adjustment value.

In the third step, if the difference between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored at the high limit or the low limit is large, the processing fails due to focus failure. ,

In addition, an optical disc device according to the present invention comprises: storage means for storing a reference value for focus balance adjustment; Detection means for detecting a focus balance adjustment value for the optical disc; And a control means for changing the detected focus balance adjustment value to an arbitrary specific value or performing a failure processing due to a focus failure in comparison with the detected focus balance adjustment value and the reference value. ,

The reference value may be separately stored as a focus balance reference adjustment range, a high limit, and a low limit, respectively.

The specific value may be any one of a focus balance adjustment value stored at the high limit or a focus balance adjustment value stored at the low limit.

In addition, the control means, if the difference value between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored as the high limit or the low limit is small, the high limit or the low limit To change the focus balance adjustment value.

Further, the control means, if the difference value between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored at the high limit or the low limit is large, the processing failure is characterized in that the failure failure processing. It is done.

The optical disk device and the focus balance adjusting method according to the present invention include, for example, in an optical disk device such as a BD-Recorder, a reference adjustment range for adjusting the focus balance, a high limit, and a low limit. Low Limit) is stored in advance, and the focus balance adjustment value for the optical disc is detected, compared with the reference value, and according to the comparison result, the detected focus balance adjustment value is determined as the high limit or the like. By changing to a low limit reference value or poorly processing due to focus failure, the focus balance adjustment value for optical discs such as BD-R / RE, which have a narrow movable range (WD) of the objective lens and a lot of spherical aberration, are optimized. This prevents the optical disc and the objective lens from colliding with each other and effectively prevents the failure of the focus servo operation. It is possible.

Hereinafter, exemplary embodiments of an optical disk device and a focus balance adjusting method according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 2 shows a configuration of an embodiment of an optical disc device to which the present invention is applied. For example, an optical disc 10, an optical pickup 11, and a recording are provided in an optical disc device such as a BD-Recorder. And a reproducing unit 12, codec 13, microcomputer 14, spindle motor 15, sled motor 16, motor driver 17, memory 18, and detecting unit 19, and the like. do.

Meanwhile, the detector 19 detects a jitter value, which is an error component of a reproduction signal, and detects an RF level of the reproduction signal in order to perform an optimal focus balance adjustment operation. .

The microcomputer 14 checks the jitter value and the RF level value detected by the detector 19. For example, as shown in FIG. 5, the jitter value is the minimum ( Min) and the focus balance adjustment value at the time when the RF level value becomes the maximum (Max) are determined as the optimal focus balance adjustment value.

On the other hand, the focus balance adjustment value is a bias driving voltage applied to the objective lens of the optical pickup and is forcibly adjusted so that the laser beam is accurately focused on the recording layer of the optical disc. For example, the BD-R / Since RE has a lot of spherical aberrations, as described above with reference to FIG. 3, RE adjusts a spherical aberration compensation lens (CL) provided under the objective lens in the optical pickup together with the objective lens. do.

For example, as shown in FIG. 6, in the case of BD-R / RE, in consideration of spherical aberration generation characteristics, a focus balance adjustment value (FBL adjustment value) and a spherical aberration adjustment value (A-CP) on line A are considered. adjustment value), and then the focus balance adjustment value and the spherical aberration adjustment value on the B line.

On the basis of the detected focus balance adjustment value and the spherical aberration adjustment value on the detected lines A and B, respectively, the optimum optimum adjustment value is detected and applied. The balance adjustment value is determined by comparing with a preset reference value to automatically change the focus balance adjustment value or perform a defect (NG) processing operation due to a focus failure.

FIG. 7 is a flowchart illustrating an embodiment of a method for adjusting a focus balance in an optical disk device according to the present invention. In the microcomputer 14, as described above with reference to FIG. In this case, in consideration of the spherical aberration generation characteristic, the FBL adjustment value and the spherical aberration adjustment value A-CP adjustment value on the A line are detected and set (S10).

Then, the RF Amp signal level detected by the detector 19 is measured (S11). After all points are measured on the A line (S12), the spherical aberration adjustment is maximized. To calculate the value and the focus balance adjustment value (S13), a well-known two-dimensional least square method (2 dimensional least squares method) is used.

In addition, in the microcomputer 14, as described above with reference to FIG. 6, the FBL adjustment value and the spherical aberration adjustment value (A-CP adjustment value) on the B line perpendicular to the A line. Is detected and set (S14).

Then, the RF Amp signal level detected by the detector 19 is measured (S15), and after all points are measured on the B line (S16), the spherical aberration adjustment is maximized. The value and the focus balance adjustment value are calculated (S17).

On the other hand, in the microcomputer 14, when the calculation operation as described above is completed, the focus balance adjustment value is determined and compared with a preset reference value (S18). 0xFF], the high limit may be set to [0xD0], and the low limit may be set to [0x30].

For example, if the focus balance adjustment value is set high, it means that the bias of the objective lens is biased to the upper limit, and that is because the focus search (Focus) is generally higher than the normal position of the objective lens. Search) or external vibration causes a collision between the objective lens and the optical disk.

On the other hand, when the focus balance adjustment value is set low, it means that the bias of the objective lens is biased to the lower side. As described above with reference to FIG. 1, in the case of the BD, the data recording layer Since it exists at a position 0.1 mm away from the cover layer, the movable range of the objective lens is narrow, and focus failure occurs when the objective lens is biased too low.

If a focus failure occurs for such a reason, the optical disk device manufacturer or the like determines that the optical pickup is defective in manufacturing and takes a series of measures for discarding.

In the present invention, in order to prevent this, the focus balance reference adjustment range [0x00 to 0xFF], the high limit [0xD0], and the low limit [0x30] are set as described above. do.

When the focus balance adjustment value is out of the high limit or the low limit, the jitter value or the RF level at the time point is measured and compared with the jitter value or the RF level at the set high / low limit. For example, if the focus balance adjustment value and the RF level value are [0x12] and [0x4000], and the low limit and the corresponding RF level value are [0x30] and [0x4200], the difference value at the two points is calculated. Done.

  On the other hand, for example, as shown in FIG. 8, when the calculated difference value is small, a series of rounding processing operations for changing the focus balance adjustment value to a low limit [0x30] is performed (S19). For example, as illustrated in FIG. 9, when the calculated difference value is large, a defect (NG) process is performed so that a later focus failure or the like does not occur.

Therefore, in the case of a BD where a lot of spherical aberration occurs and the movable range of the objective lens is narrow, the focus balance adjustment value is set too high or too low to effectively prevent the objective lens and the optical disk from colliding. do.

In addition, by changing the focus balance adjustment value, it is possible to prevent the optical pickup and the like, which can perform the normal focus operation, from being incorrectly treated as defective in the manufacturing process and discarded.

As described above, preferred embodiments of the present invention are disclosed for purposes of illustration, and those of ordinary skill in the art can further various other embodiments within the spirit and technical scope of the present invention disclosed in the appended claims. Improvements, changes, substitutions or additions will be possible.

1 shows structural features of a typical optical disc,

2 shows a moving range of a general objective lens,

3 illustrates a process of generating a general spherical aberration,

4 shows a configuration of an embodiment of an optical disk device to which the present invention is applied;

5 illustrates a process of detecting a focus balance adjustment value according to the present invention;

6 illustrates a process of detecting a focus balance adjustment value to minimize spherical aberration according to the present invention.

7 is a flowchart illustrating an embodiment of a method for adjusting a focus balance in an optical disk device according to the present invention;

8 illustrates an embodiment in which the focus balance adjustment value is changed according to the present invention.

9 illustrates an embodiment in which a defect is processed due to a focus failure according to the present invention.

[Description of Drawings]

10: optical disc 11: optical pickup

12: recording and playback section 13: codec

14: microcomputer 15: spindle motor

16: sled motor 17: motor driver

18: memory 19: detector

Claims (10)

A first step of storing a reference value for adjusting the focus balance in advance; Detecting a focus balance adjustment value for the optical disc and comparing the result with the reference value; And And changing the detected focus balance adjustment value to an arbitrary value according to the result of the comparison, or performing poor processing due to a focus failure. The method of claim 1, And the reference values are separately stored into a focus balance reference adjustment range, a high limit, and a low limit, respectively. 3. The method of claim 2, And said specific value is one of a focus balance adjustment value stored at said high limit, or a focus balance adjustment value stored at said low limit. 3. The method of claim 2, In step 3, if the difference between the RF level in the detected focus balance adjustment value and the RF level in the focus balance adjustment value stored as the high limit or the low limit is small, the focus balance of the high limit or the low limit is reduced. A method of adjusting the focus balance in an optical disk device, characterized by changing the adjustment value. 3. The method of claim 2, In the third step, if the difference between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored at the high limit or the low limit is large, the processing fails due to focus failure. How to adjust the focus balance on an optical disk device. Storage means for storing a reference value for adjusting the focus balance; Detection means for detecting a focus balance adjustment value for the optical disc; And And a control means for changing the detected focus balance adjustment value to an arbitrary specific value or inferior processing due to a focus failure in comparison with the detected focus balance adjustment value and the reference value. Optical disk device. The method of claim 6, And the reference value is separately stored into a focus balance reference adjustment range, a high limit, and a low limit. The method of claim 7, wherein And the specific value is one of a focus balance adjustment value stored at the high limit or a focus balance adjustment value stored at the low limit. The method of claim 7, wherein The control means, if the difference value between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored as the high limit or the low limit is small, the focus balance of the high limit or the low limit. And an adjustment value. The method of claim 7, wherein The control means, if the difference value between the RF level at the detected focus balance adjustment value and the RF level at the focus balance adjustment value stored at the high limit or the low limit is large, performs a failure processing due to focus failure. Optical Disc Device.
KR1020080119544A 2008-11-28 2008-11-28 Optical disc device and focus balance adjust method KR20100060798A (en)

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KR1020080119544A KR20100060798A (en) 2008-11-28 2008-11-28 Optical disc device and focus balance adjust method

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