KR20010010405A - Eccentricity adjusting apparatus for disc for data recording and/or reproduction and eccentricity adjusting method using it - Google Patents

Abstract

PURPOSE: A device for correcting the eccentricity of a disk for recording/playing back information and a method thereof are provided to correct the eccentricity of the disk at an assembling. CONSTITUTION: The recording/playback head(20), a rotary plate for encoder(50), an encoder(60), a discriminating unit and a pushing device(70) are prepared. The first eccentric amount is calculated from a maximum tracking error by rotating a disk(10). The discriminating unit searches rotary angles(theta1,theta2) of a disk when the maximum tracking error is detected. The disk is located at the angel(theta1). The disk is pushed as the first eccentric amount/2 toward a rotary shaft by the pushing device. A second eccentric amount is calculated by rotating the disk again. The disk is located at the angle(theta1) and pushed as the second eccentric amount when the first eccentric amount is larger than the second. Otherwise, the disk is located at the angle(theta2) and pushed as the second eccentric amount.

Description

Eccentricity adjusting apparatus for disc for data recording and / or reproduction and eccentricity adjusting method using it}

The present invention relates to an information recording and reproducing disk eccentric correction apparatus for correcting eccentric rotation of an information recording and reproducing disk in an assembling process, and an eccentric correction method using the same.

In general, in a device using a rotating disk as a medium for information recording and / or reproduction, such as a hard disk drive, as shown in FIG. 1, a track on which information is stored is formed on the disk 1, and The track is followed by the recording / playback head 2 to reproduce or record the information. Here, the disk 1 is fitted to the coupling boss 3a of the spindle motor 3 and then clamped and fixed by the clamper 4. Therefore, when the spindle motor 3 is driven, the clamper 4 and the disk 1 rotate together. Since the spindle motor 3 is a turntable integrated type, a separate turntable is not provided. Reference numeral S denotes a screw for fastening the clamper 4 to the spindle motor 3.

By the way, the through hole 1a of the disk 1 fitted to the coupling boss 3a is formed slightly larger than the diameter of the coupling boss 3a for smooth insertion. Thus, since the disk 1 can move slightly over the spindle motor 3, its exact center point can be displaced from the center of the rotation axis 3b of the spindle motor 3. As such, when the disk 1 is fixed and rotated in the state where the center point is distorted, the disk 1 cannot rotate while drawing the correct circle, and as shown in FIG. In this case, the track of the disc 1 is also eccentrically rotated, so that the recording / playback head 2 cannot accurately follow the track. Therefore, if a tracking error occurs due to the eccentric rotation, it adversely affects the recording and reproduction of the information. Of course, the recording and playback head 2 is servo controlled so as to follow the track of the disc 1 by a tracking servo control system (not shown) during recording and reproduction of information, When mounted eccentrically, the control wall of the servo control system increases, resulting in a decrease in information recording and reproducing performance. Therefore, there is a need for a calibration device and a calibration method for assembling the center of the disk and the center of the rotating shaft of the spindle motor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above point, and an object of the present invention is to provide an eccentric correction apparatus for an information recording and reproducing disk which can correct an eccentricity of a disk during assembly, and a calibration method using the same.

1 is a diagram showing a clamping structure of a disc for general information recording and reproducing;

2 is a diagram illustrating an eccentric rotation state of a disk;

3 is a view showing an eccentric correction device according to the present invention,

4a and 4b is a view showing a coupling structure of the rotary plate for the encoder of the eccentric correction device shown in FIG.

5 is a view showing the shape of the mark for the encoder of the eccentric correction device shown in FIG.

6 is a view showing the structure of the pushing means of the eccentric correction device shown in FIG.

7 is a flow chart sequentially showing the eccentricity correction method according to the present invention,

8 is a signal output chart showing that the eccentric amount and the eccentric position are output by the eccentric correction apparatus shown in FIG.

9 is a view schematically illustrating a process of calculating θ ₁ and θ ₂ of the output chart of FIG. 8;

FIG. 10 is a diagram showing Ad and θ ₁ and θ ₂ in the output chart of FIG. 8 on a disc; FIG.

<Description of the reference numerals for the main parts of the drawings>

10 ... disc 20 ... recording playback head

30 ... spindle motor 31 ... spindle

40 ... clamper 50 ... turning plate for encoder

51 Mark 60 Encoder

70 Pushing means 71 Pushpin

72 ... push cap 73 ... spring

100 ... controller

The eccentricity correction apparatus of the present invention for achieving the above object is an eccentricity of a disc for information recording and reproducing for diagnosing the eccentricity of a disc from a tracking error signal detected by the recording / reproducing head by the eccentric rotation of the disc and correcting the eccentricity thereof. A calibration apparatus, comprising: rotation position sensing means for tracking a rotation angle of the disc to find out a rotation angle of the disc when the tracking error is maximized by an eccentric rotation; And a pushing means for reducing the amount of eccentricity by pushing the disk toward the rotation axis when the disk is positioned at the maximum eccentricity detected position detected by the rotation position detecting means.

In addition, the eccentric correction method of the present invention for achieving the above object is provided with a recording and playback head for recording information or reading information from the track of the disc for information recording and reproducing, and coaxial with the rotation axis of the disc. An encoder for rotating the disc and having a mark for setting a reference position of the disc rotating angle on one surface thereof, an encoder for detecting and tracking the mark of the disc based on the mark of the encoder rotating plate; A discrimination unit which receives the rotation angle data tracked by the encoder and the tracking error data detected by the recording and playback head and calculates the disk rotation angle when the tracking error is maximum, and presses the disk toward the center of the rotation axis. Pushing means installed so as to be able to move forward and backward in an adjacent position of the disk Compared to step; Calculating an eccentricity Ad ₁ from the maximum tracking error detected by the recording and playback head while rotating the disc; Finding disc rotation angles θ ₁ and θ ₂ when the maximum tracking error is detected by the determination unit; Positioning the disk at an θ ₁ angle; Driving the pushing means to push the disk toward the center of the rotation axis by Ad _1/2 ; Rotating the disc again and detecting a maximum tracking error with the recording / playback head and calculating an eccentricity Ad ₂ therefrom; Comparing the magnitude of the calculated eccentricity Ad ₁ and Ad ₂ ; If the eccentricity Ad ₁ is greater than Ad ₂ , positioning the disc again at an angle of θ ₁ and driving the pushing means to push the disc toward the center of the rotation axis by Ad ₂ ; And when the eccentricity Ad ₁ is smaller than Ad ₂ , positioning the disc at an angle θ ₂ and driving the pushing means to push the disc toward the center of the rotation axis by Ad ₂ .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 shows the configuration of the eccentric correction apparatus according to the present invention.

Referring to the figure, an information recording and reproducing disk 10 is seated on the spindle motor 30, and a clamper 40 for crimping and supporting the disk 10 is fastened and fastened with a screw S thereon. At this time, by leaving the screw (S) in a slightly loose pretightening state without completely tightening, the disk 10 can be moved by intentionally pushing strongly on the spindle motor 30. And the upper part of the clamper 40, as shown in Figures 4a and 4b, the rotary plate 50 for the encoder is attached by a magnet (52). Reference numeral 32 denotes an iron plate installed on the spindle motor 30 for magnetic coupling with the magnet 52. Accordingly, the rotary plate 50 for the encoder rotates together with the disk 10 and the clamper 40 integrally, and a mark 51 is formed on one surface for setting a reference position of the disk 10 rotation angle. have. As shown in Fig. 5, the mark 51 is formed in a two-layer mark structure in which starting points are shifted from each other, so that the encoder 60 that recognizes the mark 51 is the first-layer mark 51a or the second layer. Which one of the marks 51b is detected first can be known to its rotation direction.

In addition, the pushing unit 70 is provided at a position adjacent to the disk 10 to push the disk 10 toward the center of the rotation shaft 31. As shown in FIG. 6, the pushing means 70 includes a push pin 71 provided to be able to move forward and backward to press the disk 70 toward the center of the rotating shaft, and an edge portion of the disk 10. The push cap 72 is placed on the push pin 71 to press directly, and is installed between the push pin 71 and the push cap 72 when the push cap 72 strikes the disk 10. It is configured to include a spring 73 for cushioning the impact. The push pin 71 may be formed of, for example, a piezoelectric element or the like, and is positioned opposite to the recording / playing head 20 with respect to the center of the rotation axis 31 of the disk 10. The rotary shaft 31 is installed to be pressed toward the center. The push pin 71 and the push cap 72 are conductors, and the spring 73 is an insulating spring. In this state, when the push pin 71 moves forward and the push cap 72 starts to contact the disc 10, the disc 10 does not move during the compression section because the spring 73 is first compressed. . Then, when the spring 73 is completely compressed so that the tip of the push pin 71 touches the inner wall of the push cap 72, the disk 10 is pushed thereafter. Therefore, the length control of the controller 100 for moving the disk 10 starts as soon as the push pin 71 and the push cap 72 are in contact as described above. However, the moment when the push pins 71 and the push caps 72 come into contact with each other is the same as that of the electric circuit cut by the insulating spring 73 at the moment when the two members contact each other. 100 detects and starts to control the pushing length from this time.

In the above configuration, eccentricity correction of the disk proceeds along the flow chart in FIG.

First, as shown in FIG. 3, the clamped disk 10 is rotated between the spindle motor 30 and the clamper 40 (S1). Of course, at this time, the recording and playback head 20 checks whether the disk 10 is seated (S2). Then, by rotating the disc 10, the periodic tracking error signal sensed by the recording and playback head 20 is measured, and the disc eccentricity is calculated therefrom (S3). In this case, the encoder 60 detects and reads the position of the mark 51 as the rotary plate 50 for the encoder rotates, and continuously tracks the rotation angle of the disc 10 based on the reference. Therefore, as shown in the output chart shown in FIG. 8, the rotation angles θ ₁ and θ ₂ of the disc 10 when the maximum amount of eccentricity is detected by the recording / playback head 20 can be found (S4). θ ₂ has a phase difference of 180 ° with θ ₁ , because when the amount of eccentricity is maximized in the + direction from θ ₁ , it becomes maximum in the − direction at the θ ₂ position that is rotated 180 °. The tracking error zero cross signal of FIG. 8 is converted into a form in which a signal occurs every time the tracking error signal passes the average zero point, and finds θ ₁ and θ ₂ by its roughness. . FIG. 9 is a diagram schematically illustrating the rotation error data tracked by the encoder 60 and the tracking error data detected by the recording / reproducing head 20 in the determination unit of the controller 100. The disc rotation angles θ ₁ and θ _{2 when} are calculated. When θ ₁ and θ ₂ are found in this manner, the disk 10 is rotated and positioned at an angle of θ ₁ (S5). In this case, since the recording and playback head 20 and the pushing means 70 are installed to face each other with respect to the center of the rotation shaft 31 as shown in FIG. 10, θ ₁ , which is the position where the maximum amount of eccentricity is detected in the recording and playback head 20. Alternatively, when the disk 10 is turned by θ ₂ , the pushing means 70 is naturally located at the point. In this state, the push pin 71 of the pushing means 70 is advanced to move the disc 10 toward the center of the rotation axis by Ad _1/2 (S6). This can be expected to reduce the amount of eccentricity that was Ad ₁ by half. If the position of θ ₁ is the maximum point in the-direction, the amount of eccentricity is increased. Therefore, to correct this, while rotating the disk again, the new eccentricity Ad ₂ is measured (S7). Thus, the magnitudes of Ad ₁ and Ad ₂ are compared with each other (S8). At this time, if Ad ₁ is large, the pressing position of the pushing means 70, that is, the θ ₁ position, is an accurate position as the pressing position and thus the amount of eccentricity. In other words, the eccentricity is reversed as the position where θ ₂ is correct, rather than θ ₁ . Therefore, after the location when the Ad ₁ is large, the disk 10 back to the θ ₁ (S9), the pushing means 70 to moves the disk 10 by Ad ₂ (S11), Ad case ₂ is larger, Place the disk 10 in the θ ₂ (S10), similarly to the pressing movement in the pushing means 70 by Ad ₂ thereby (S11). Thereafter, the screw 10, which has been pre-tightened, may be tightened to completely tighten the disk 10 so that the disk 10 does not move (S12). After the calibration is completed, the rotary plate 50 for the encoder is removed.

In this way, the eccentricity at the time of assembling the disk 10 between the spindle motor 30 and the clamper 40 is corrected.

As described above, according to the eccentricity correction apparatus and the eccentricity correction method of the disc for information recording and reproducing according to the present invention, the eccentricity can be sufficiently corrected in advance in the assembling process of the disc. Can greatly reduce the possibility of error occurrence.

It is to be understood that the invention is not limited to that described above and illustrated in the drawings, and that more modifications and variations are possible within the scope of the following claims.

Claims (6)

In the eccentricity correction apparatus for an information recording and reproducing disc for diagnosing the eccentricity of a disc and correcting the eccentricity thereof from a tracking error signal detected by the recording and playback head by the eccentric rotation of the disc, Rotational position detecting means for tracking the rotational angle of the disk and finding the rotational angle of the disk when the tracking error is maximized by the eccentric rotation; And a pushing means for reducing the amount of eccentricity by pushing the disk toward the rotation axis when the disk is positioned at the maximum eccentricity detected position by the rotation position detecting means. The method of claim 1, The rotation position detecting means, An encoder rotating plate installed coaxially with the rotation axis of the disk and rotating together with the disk, and having a mark formed on one surface thereof to set a reference position of the disk rotation angle; An encoder for detecting a mark of the rotating plate for the encoder and calculating and tracking a rotation angle of the disc based on the mark; And, And a judging unit which receives the rotation angle data tracked by the encoder and the tracking error data detected by the recording / reproducing head and calculates the disk rotation angle when the tracking error is maximum. Disc eccentricity correction device. The method of claim 2, The mark is, An eccentricity correction apparatus for an information recording and reproducing disc, characterized in that the first layer and the second layer mark are first detected according to the rotational direction of the disc. The method of claim 1, The pushing means, Push pins are provided to be moved forward and backward in the adjacent position of the disk to press the disk toward the center of the rotation axis; A push cap on the push pin to be in direct contact with the rim of the disk; And a spring provided between the push pin and the push cap so that the push cap is elastically cushioned and pressurized by the edge portion of the disk. The method of claim 4, wherein The push pin and the push cap is a conductor and the spring is composed of an insulator, so that the spring is compressed so that the push pin and the push cap is in contact with the electrical circuit can be detected. Disc eccentricity correction device. A recording / playing head for recording or reading information while following a track of an information recording / reproducing disc, and a shaft which is installed coaxially with the rotating shaft of the disk and rotates with the disk, and has a reference position of the rotating angle of the disk on one surface thereof. An encoder for forming a mark for setting an encoder, an encoder for detecting a mark of the encoder for the encoder and calculating and tracking a rotation angle of the disc based on the mark, and detecting the rotation angle data tracked by the encoder and the recording / reproducing head A discrimining unit for receiving the tracking error data to calculate the disc rotation angle when the tracking error is maximum, and a pushing means installed forward and backward at an adjacent position of the disc to press the disc toward the center of the rotation axis. Preparing; Calculating an eccentricity Ad ₁ from the maximum tracking error detected by the recording and playback head while rotating the disc; Finding disc rotation angles θ ₁ and θ ₂ when the maximum tracking error is detected by the determination unit; Positioning the disk at an θ ₁ angle; Driving the pushing means to push the disk toward the center of the rotation axis by Ad _1/2 ; Rotating the disc again and detecting a maximum tracking error with the recording / playback head and calculating an eccentricity Ad ₂ therefrom; Comparing the magnitude of the calculated eccentricity Ad ₁ and Ad ₂ ; If the eccentricity Ad ₁ is greater than Ad ₂ , positioning the disc again at an angle of θ ₁ and driving the pushing means to push the disc toward the center of the rotation axis by Ad ₂ ; Positioning the disc at an angle of θ ₂ when the eccentric amount Ad ₁ is smaller than Ad ₂ and driving the pushing means to push the disc toward the center of the rotation axis by Ad ₂ ; Eccentric correction method.