JP2000057684A - Disk recording and/or reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk recording and/or reproducing device which is capable of correcting the perpendicularity error and/or the misalignment for every disk recording and/or reproducing device and also making the perpendicularity error and/or the misalignment to be correctable for every disk, and which is capable of making the perpendicularity follow up zero even in a high multiple- speed disk recording and/or reproducing device which rotate a disk at high speed. SOLUTION: Signals from perpendicularity detectors and misalignment detectors are inputted to a rotating body position controller 23, which controls a magnetic beraring so that the value of perpendicularity and the value of a misalignment respectively become zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording / reproducing apparatus, and more particularly, to correcting a squareness error and / or misalignment for each disk recording / reproducing apparatus and for each disk, and rotating the disk at high speed. The present invention also relates to a disk recording / reproducing apparatus that can make a right angle follow zero even in a high-speed disk recording / reproducing apparatus.

[0002]

2. Description of the Related Art The principle of a disk recording / reproducing apparatus will be briefly described with reference to FIGS. 2 and 3, an optical disc 1 such as a CD or a DVD is rotated by a spindle motor 5 about an axis of a rotating body 3. A pickup 7 is provided for irradiating a recording surface of the disk 1 for signal recording with laser light and receiving the laser light reflected on the recording surface. The deviation value (or the nominal value of the squareness at predetermined time intervals) when the angle between the optical axis 9 of the laser beam emitted from the pickup 7 and the predetermined range of the recording surface of the disk 1 deviates from 90 degrees is determined. It is a right angle.

On the other hand, a pickup 7 tracks a data recorded on the disk 1 and along a guide rail (not shown) so that the laser optical axis 9 is parallel to the disk 1 and extends from the inner circumference to the outer circumference of the disk 1. Moving. At this time, it is ideal that the curvature center 11 of the signal track formed on the recording surface of the disk 1 is located on an extension of the movement locus of the point where the laser optical axis 9 intersects the recording surface of the disk 1. Generally, misalignment (hereinafter, referred to as
Misalignment) has occurred.

[0004] This misalignment is caused by the laser optical axis 9
Is defined as the distance between the extension of the movement trajectory of the point intersecting the recording surface and the center of curvature 11 of the signal track formed on the recording surface of the disk 1. To perform accurate signal recording and / or signal reading, it is necessary to keep the values of the squareness and the misalignment within acceptable ranges.

For this reason, in the conventional disk recording / reproducing apparatus, an inclination adjusting mechanism 13 as shown in FIG. 4 is provided on a pedestal of the spindle motor 5 to adjust the inclination in a production process or to record and / or record signals. The apparatus includes tilt servo control means for detecting the squareness during reading and controlling the orientation of the entire pickup 7 and its guide rails so that the squareness becomes zero. Further, a misalignment adjusting mechanism (not shown) for adjusting the direction of the guide rail of the pickup 7 is provided, and this is adjusted in the production process.

[0006]

However, in the conventional tilt adjusting mechanism 13 and the misalignment adjusting mechanism, the squareness error and the center error caused by the shape error and the assembly error of the rotating mechanism component of the disk 1 and the driving mechanism component of the pickup 7 are not considered. Shift
Although it is possible to correct for each disk recording / reproducing device, it has the drawback that it cannot correct the squareness error and misalignment caused by unspecified disk warpage and eccentricity of the center of curvature of signal holes and center tracks. .

The conventional tilt servo control means changes the direction of the entire pickup 7 and its guide rails, so that the inertia of the control target is large, the response of the control system is low, and the high-speed disk for rotating the disk at high speed. The recording / reproducing apparatus has a drawback that the squareness cannot follow zero.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and it is possible to correct a squareness error and / or a misalignment for each disk recording and / or reproducing apparatus and also for each disk. It is an object of the present invention to provide a disk recording and / or reproducing apparatus capable of causing a right angle to follow 0 even in a high-speed disk recording and / or reproducing apparatus which rotates the disk at high speed.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention provides at least one magnetic bearing means for supporting a rotating body and capable of adjusting the inclination of the rotating body, a rotating means for rotating the rotating body, A table fixed to the rotating body or integrally formed with the rotating body, and a pickup for irradiating the recording surface of the disc mounted on the table with laser light and receiving the laser light reflected on the recording surface, A squareness detecting means for detecting a squareness where an optical axis of the laser light emitted from the pickup forms a predetermined range of the recording surface of the disk; and a squareness detected by the squareness detecting means being zero or a predetermined tolerance. Control means for controlling the magnetic bearing means so as to fall within the range to adjust the inclination of the rotating body.

The shape of the rotating body is not limited. For example,
It may be a solid shaft or a hollow cylinder. The perpendicularity detecting means detects a perpendicularity where an optical axis of the laser beam emitted from the pickup is within a predetermined range of the recording surface of the disk. This perpendicularity is desirably 0. If the perpendicularity increases due to the warpage of the disk or the like, data cannot be accurately recorded on the recording surface of the disk or data cannot be accurately extracted from the recording surface of the disk. For this reason, the control means controls the magnetic bearing means to adjust the inclination of the rotating body so that the squareness is 0 or within a preset allowable range (error close to 0).

At least one magnetic bearing means is provided so as to support the rotating body and adjust the inclination of the rotating body. The reason why at least one is used is that one end of the rotating body may be supported by a bearing other than a magnetic bearing such as a pivot bearing. As described above, the squareness error can be corrected for each disk.

Further, the present invention provides at least one magnetic bearing means for supporting a rotating body and adjusting the inclination and / or the radial position of the rotating body, rotating means for rotating the rotating body, A table fixed to the rotating body or integrally formed with the rotating body, and a pickup for irradiating the recording surface of the disc mounted on the table with laser light and receiving the laser light reflected on the recording surface, Misalignment detecting means for detecting a distance between an extended line of a movement locus of an optical axis of the laser beam accompanying the movement of the pickup toward a rotation center direction of the disk and a center of curvature of a signal track on a recording surface of the disk. Controlling the magnetic bearing means so that the distance detected by the misalignment detecting means is equal to 0 or within a preset allowable range, thereby controlling the inclination and / or radial position of the rotating body. Was constructed and a control means for adjusting the.

The value of the misalignment detected by the misalignment detecting means is 0.
It is desirable that If the value of misalignment increases due to the eccentricity of the center hole of the disk or the center of curvature of the signal track, it becomes impossible to accurately record data on the recording surface of the disk or to extract data accurately from the recording surface of the disk. For this reason, the inclination and / or the radial position of the rotating body is adjusted by the control means so that the value of the misalignment is 0 or within an allowable range (error range close to 0). From the above,
The misalignment value can be corrected for each disk.

Further, the present invention provides at least one magnetic bearing means for supporting a rotating body and adjusting the inclination and / or the radial position of the rotating body, a rotating means for rotating the rotating body, A table fixed to the rotating body or integrally formed with the rotating body, and a pickup for irradiating the recording surface of the disc mounted on the table with laser light and receiving the laser light reflected on the recording surface, Squareness detecting means for detecting a squareness of an optical axis of a laser beam emitted from the pickup with respect to a predetermined range of a recording surface of the disk, and the laser associated with movement of the pickup toward a center of rotation of the disk. A misalignment detecting means for detecting a distance between an extension of a movement locus of an optical axis of light and a center of curvature of a signal track on a recording surface of the disk; and a squareness detecting means. The magnetic bearing means is controlled to adjust the inclination and / or the radial position of the rotating body so that the output perpendicularity and the distance detected by the misalignment detecting means are both 0 or within a predetermined allowable range. And control means for performing the control.

According to the present invention, both the squareness detecting means and the misalignment detecting means are provided, and the magnetic bearing means is controlled in accordance with the outputs of the respective means so that the squareness and the misalignment are each 0 or within a predetermined allowable range. (Ideally 0)
Adjust the tilt and / or radial position of the rotator. This makes it possible to correct, for each disk, unspecified disk warpage, squareness error and misalignment caused by eccentricity of the center hole and the center of curvature of the signal track, and therefore, it is possible to perform signal recording and / or signal reading on the disk. Thus, it is possible to provide a highly reliable disk recording / reproducing apparatus.

Furthermore, the present invention is characterized in that the magnetic bearing means has an upper radial position control electromagnet and / or a permanent magnet for adjusting an upper radial position of the rotating body.

In order to adjust the upper radial position of the rotating body, an electromagnet for controlling the upper radial position is provided. However, the upper radial position control electromagnet can be replaced with a permanent magnet, or the upper radial position control electromagnet and the permanent magnet can be used in combination.

Further, the present invention is characterized in that the magnetic bearing means has a lower radial position control electromagnet and / or a permanent magnet for adjusting a lower radial position of the rotating body. .

The lower radial position adjustment of the rotating body can be configured in the same manner as described in the upper radial position adjustment.

Further, the present invention is characterized in that the magnetic bearing means further comprises an electromagnet and / or a permanent magnet for axial position control for axially supporting the rotating body.

An electromagnet and / or a permanent magnet for axial position control are used to magnetically levitate and support the rotating body in the axial direction. As described above, since the inclination of the magnetically levitated disk and the rotating body may be controlled, the mass of the control target is small, the control system has high responsiveness, and high-speed rotation is possible.

Further, according to the present invention, there is provided an electric motor wherein the rotating means is disposed between the upper radial position controlling electromagnet and / or the permanent magnet and the lower radial position controlling electromagnet and / or the permanent magnet. It is characterized by having a winding.

The rotating body is supported at two points on the upper side and the lower side, and the motor winding is disposed therebetween, so that control is stabilized.

Further, according to the present invention, in the magnetic bearing means, the magnetic force generated by the motor winding provided in the rotating means is generated by the upper radial position controlling electromagnet or the lower radial position controlling electromagnet. The radial position is magnetically adjusted while generating a rotational force by being unbalanced by the applied magnetic force.

As in the case of a bearingless motor, the magnetic force generated by the motor winding is unbalanced by the magnetic force generated by the radial position control electromagnet, so that the radial position is magnetically generated while the rotational force is generated. adjust. As described above, the radial position control electromagnet and the axial position control electromagnet can be reduced in size and power consumption.

The present invention is applicable not only to a disk recording-only device or a disk reproduction-only device, but also to a disk recording and reproducing device.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention.
In FIG. 1, a table is fixed on the upper part of the rotating body 3, and the disc 1 is mounted on the table.
Since these configurations are the same as those conventionally used conventionally, they are not shown. The point at which the pickup 7 irradiates the recording surface of the disk with laser light is shown in FIG.
3 is omitted because it is the same as FIG.

To adjust the upper radial position of the rotator 3, the upper radial position control electromagnets V1, V3, W
1, W3 are arranged symmetrically with respect to the rotating body 3. Similarly, in order to adjust the lower radial position of the rotating body 3, the lower radial position control electromagnets V2, V4, W2,
W4 is arranged symmetrically with respect to the rotating body 3. Further, a metal disk 26 is fixed to the rotating body 3.
In order to adjust the axial position of the metal disk 26,
The axial position control electromagnets Z1 and Z2 are provided.

The upper electromagnet V for radial position control
1, V3, W1, W3, electromagnets V2, V4, W2, W4 for lower radial position control and electromagnet Z for axial position control
Part of Z1 and Z2 can be replaced with permanent magnets, or can be used in combination with permanent magnets.

As the squareness detector and the misalignment detector, those conventionally used may be used, and are not shown here. Signals from the squareness detector and the misalignment detector are input to the rotating body position controller 23. Then, the rotating body position control device 23
Are electromagnets V1, V3, W1, W3, V2, V4, W2, W2 based on signals from the squareness detector and the misalignment detector, so that the values of the squareness and misalignment become 0, respectively.
4, Z1, Z2 by adjusting the magnetic force, the rotating body 3
Is controlled. The rotating body position control device 23 corresponds to a control unit.

The armature of the motor for rotatingly driving the rotating body 3 is not shown for simplicity, but the first radial position control electromagnets V1, V3, W1, W3 and the second
Is preferably provided between the radial position control electromagnets V2, V4, W2, and W4. However, an end face motor may be configured on the lower end face side of the rotating body 3.

Next, the operation will be described. The signals from the squareness detector and the misalignment detector are input to the rotator position controller 23. The rotating body position control device 23 controls the electromagnets V1, V3, W so that the values of the squareness and the misalignment become zero.
The position of the rotating body 3 is controlled by adjusting the magnetic force of 1, W3, V2, V4, W2, W4, Z1, Z2. Then, this series of operations is continuously repeated while signal recording and / or signal reading is performed.

By the above-described method, the squareness error and the misalignment caused by the shape error and the assembly error of the disk rotating mechanism component and the pickup driving mechanism component are corrected, and the unspecified disk warpage, the center hole, and the signal track are corrected. And the misalignment caused by the eccentricity of the center of curvature can be corrected for each disk.

Therefore, the reliability of signal recording and / or signal reading can be improved. Further, since the mass of the control target is small and the responsiveness of the control system is high as compared with the conventional tilt servo control means, the squareness can follow zero even in a high-speed disk recording / reproducing apparatus. Further, since the rotating body 3 is supported in a non-contact manner, the disk 1 can be rotated at a high speed.

By the way, the right angle can be adjusted by adjusting the inclination of the rotating body 3 in a direction in which the squareness becomes zero. Specifically, only the upper radial position of the rotating body 3 or the lower radial You may adjust only the direction position,
Both of these may be adjusted.

For the adjustment of the misalignment, the rotating body 3 is translated in a direction in which the value of the misalignment becomes zero, that is, both the upper radial position and the lower radial position of the rotating body 3 are adjusted. Can be performed.

Incidentally, although omitted in the above description, the axial position of the rotating body 3 is adjusted by the electromagnets Z1 and Z2. This adjustment is performed so that the axial position of the rotating body 3 matches a predetermined command value. Further, the displacement of the pickup and the recording surface of the disk due to the adjustment of the inclination of the rotating body 3, that is, the displacement of the focal position of the pickup may be corrected.

It should be noted that the present invention relates to a disc recording device,
The present invention can be applied to both a disk playback dedicated device and a disk recording / playback device. Further, in the above embodiment, an example in which both the squareness and the misalignment are adjusted has been described. However, only the squareness may be adjusted, or only the misalignment may be adjusted.

Further, the magnetic bearing means may be configured to adjust only the radial position above or below the rotating body 3. For example, the upper radial position of the rotating body 3 is magnetically supported and adjusted by the electromagnets V1, V3, W1, W3 in FIG. 1, and a lower bearing than the magnetic bearing such as a pivot bearing is used for the lower side of the rotating body 3. You may support it. However, when both the radial position and the axial position of the rotating body 3 are supported by the magnetic bearing means, the rotating body 3 can be supported in a non-contact manner, so that the highest speed rotation is possible.

[0040]

As described above, according to the present invention, at least one radial position of the rotating body is magnetically adjusted so that the values of the squareness error and / or misalignment are 0 or within an allowable range. Since the adjustment is performed, the squareness error and / or misalignment can be corrected for each disk recording / reproducing device and also for each unspecified disk.

Further, since the control system for performing this adjustment has high responsiveness, this adjustment can be performed even in a high-speed disk recording / reproducing apparatus. Further, by magnetically supporting and adjusting both the radial position and the axial position of the rotating body with a magnetic bearing, the rotating body can be supported in a non-contact manner, and the disk can be driven at high speed.

[0042]

[Brief description of the drawings]

FIG. 1 is a main configuration diagram of an embodiment of the present invention.

FIG. 2 is a simplified side view illustrating the principle of a disk recording / reproducing apparatus.

FIG. 3 is a simplified plan view illustrating the principle of a disk recording / reproducing apparatus.

FIG. 4 shows a conventional tilt adjusting mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Disk 3 Rotating body 23 Rotating body position control device 26 Metal disk V1, V3, W1, W3 Upper-side radial position control electromagnet V2, V4, W2, W4 Lower-side radial position control electromagnet Z1, Z2 Axial position control Electromagnet

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 28, 1998 (1998.8.2
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art The principle of a disk recording / reproducing apparatus will be briefly described with reference to FIGS. 2 and 3, an optical disc 1 such as a CD or a DVD is rotated by a spindle motor 5 about an axis of a rotating body 3. A pickup 7 is provided for irradiating a recording surface of the disk 1 for signal recording with laser light and receiving the laser light reflected on the recording surface. The value of the deviation when the optical axis 9 of the laser beam emitted from the pickup 7 is the angle formed with a predetermined range of the recording surface of the disk 1 deviates from 90 degrees (or nominal value of the predetermined time value of the deviation) Is a right angle.

Continued on the front page (72) Inventor Akira Shimada 4-3-1 Yashiki, Narashino-shi, Chiba Seiko Seiki Co., Ltd. (72) Inventor Hiroshi Segawa 4-3-1 Yashiki, Narashino-shi, Chiba Seiko Seiki Co., Ltd. In-company (72) Inventor Ikuo Muto 4-3-1 Yashiki, Narashino-shi, Chiba F-term (reference) in Seiko Seiki Co., Ltd. 5D109 BB19 DA01 DA14 DA15 5H303 AA22 BB03 BB06 BB14 CC01 DD01 DD11 GG11 KK22 5H607 BB01 CC05 FF01 GG17 HH01 HH08

Claims (8)

[Claims] At least one magnetic bearing means for supporting a rotating body and adjusting the inclination of the rotating body, a rotating means for rotating the rotating body, fixed to the rotating body or integrally with the rotating body. A molded table, a pickup that irradiates a laser beam onto a recording surface of a disc mounted on the table and receives laser light reflected by the recording surface, and a light beam of the laser beam emitted from the pickup Squareness detecting means for detecting a squareness of an axis forming a predetermined range of the recording surface of the disk, and the magnetic bearing means such that the squareness detected by the squareness detecting means is 0 or within a predetermined allowable range. Control means for controlling the inclination of the rotating body by controlling the rotation of the rotating body. 2. At least one magnetic bearing means for supporting a rotating body and adjusting a tilt and / or a radial position of the rotating body, a rotating means for rotating the rotating body, and fixed to the rotating body. A table integrally formed with the rotating body, a pickup for irradiating the recording surface of the disk mounted on the table with laser light and receiving the laser light reflected on the recording surface, and rotating the disk. Misalignment detecting means for detecting a distance between an extension of a movement locus of an optical axis of the laser beam accompanying movement of the pickup toward a center direction and a center of curvature of a signal track on a recording surface of the disc; Control for adjusting the tilt and / or radial position of the rotating body by controlling the magnetic bearing means so that the distance detected by the detecting means is 0 or within a preset allowable range. Means for recording and / or reproducing information on a disc. 3. At least one magnetic bearing means for supporting the rotating body and adjusting the inclination and / or the radial position of the rotating body, rotating means for rotating the rotating body, and fixed to the rotating body. A table integrally formed with the rotating body, a pickup for irradiating the recording surface of the disc mounted on the table with laser light and receiving the laser light reflected on the recording surface, and irradiating from the pickup. A squareness detecting means for detecting a squareness of an optical axis of the laser beam to be formed with a predetermined range of the recording surface of the disk, and an optical axis of the laser beam accompanying the movement of the pickup toward a rotation center direction of the disk. Misalignment detecting means for detecting the distance between the extension of the movement locus of the disc and the center of curvature of the signal track on the recording surface of the disk; and the squareness and squareness detected by the squareness detecting means. Control means for controlling the magnetic bearing means so as to adjust the inclination and / or the radial position of the rotating body so that the distances detected by the center deviation detecting means and the distances detected by the misalignment detecting means are both 0 or within a predetermined allowable range. A disc recording and / or reproducing apparatus characterized by comprising: 4. The magnetic bearing means according to claim 1, wherein said magnetic bearing means comprises an upper radial position control electromagnet and / or a permanent magnet for adjusting an upper radial position of said rotating body. 3. The disc recording and / or reproducing apparatus according to 3. 5. The magnetic bearing device according to claim 1, wherein the magnetic bearing means includes a lower radial position control electromagnet and / or a permanent magnet for adjusting a lower radial position of the rotating body. 5. The disc recording and / or reproducing apparatus according to 2, 3, or 4. 6. The magnetic bearing means further includes an electromagnet for axial position control for supporting the rotating body in an axial direction, and / or
6. The disk recording and / or reproducing apparatus according to claim 4, further comprising a permanent magnet. 7. The rotating means includes an electric motor winding disposed between the upper radial position control electromagnet and / or the permanent magnet and the lower radial position control electromagnet and / or the permanent magnet. 7. The disc recording and / or reproducing apparatus according to claim 5, wherein: 8. The magnetic bearing means, wherein the magnetic force generated by the motor winding provided in the rotating means is not affected by the magnetic force generated by the upper radial position control electromagnet or the lower radial position control electromagnet. 8. The disk recording and / or reproducing apparatus according to claim 1, wherein the radial position is magnetically adjusted while generating a rotational force by being balanced. .