CN1273668A

CN1273668A - Disk apparatus

Info

Publication number: CN1273668A
Application number: CN99801119A
Authority: CN
Inventors: 江口胜则; 菊川正明
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1998-07-17
Filing date: 1999-07-08
Publication date: 2000-11-15
Also published as: WO2000004542A1; KR20010023980A; JP2000040281A; TW509934B

Abstract

In an art of canceling the unbalance of a disk by utilizing globes, the present invention provides a disk apparatus which can efficiently cancel the unbalance, and prevent the occurrence of unnecessary noises, and further, does not induce the occurrence of errors when the speed is shifted or when the spinning-up is made. In a disk apparatus which comprises a subbase (6), a main base (8), and a turn table (9), and further a balancer including members such as a magnet (27) and globes (13), and is to cancel the unbalance of a disk (1) by utilizing movements of the globes (13), an improvement wherein the magnet (27), which a clamper (10) contains to hold the disk (1), is magnetized by polarization into four or more poles in a rotational direction or by polarization in a direction of a rotational axis or in a radial direction.

Description

Disk set

Technical field

The present invention relates to a kind of disk set (disk apparatus), it has one and can suppress because as the antivibration device of the unbalanced self-vibration that causes of the disk of recording medium, and can carry out stable record and playback.

Background technology

In recent years, the record and the disk set of replay data become more and more faster as the data rate of CD-ROM drive etc.The high-speed transfer of data needs the high speed rotating of disk.Many traditional disks are unbalanced disks, and they are owing to for example factor such as in uneven thickness causes the unbalance of quality.This disk following problem can occur when high speed rotating: for example because the unbalanced force of disk has caused the disk self-vibration, and make self-vibration pass to whole device, thereby data can not stably be reset, perhaps should vibration can produce the serviceable life that noise maybe can shorten motor, in addition, when having a drive unit in the computing machine, this vibration will be transferred to peripherals and peripherals will be caused pernicious interference.Therefore, the high speed rotating by disk comes high speed transmission data just to need to suppress because the unbalanced self-vibration that causes of disk.Therefore for eliminating the unbalanced various measures of having taked.

Hereinafter will describe having the traditional magnetic disk device of eliminating unbalanced function.

Fig. 7 is provided with a balanced device to eliminate the skeleton view of unbalanced disk set.Disk of label 1 expression, it is placed on the turntable 9 and by spindle motor 2 driven in rotation.The data of light picker 3 reading and recording on disk 1, or data are write in the disk 1.Utilize the function of light picker drive system 5 to convert the rotation of light picker drive motor 4 to linear movement, thereby light picker 3 is moved along the radial friction of disk 1.Above-mentioned these mechanical systems all are installed on the base 6, and this base 6 elastic insulated 7 by a low rigidity links to each other with main basal base 8, and wherein this insulating part 7 can alleviate the vibration of importing into from the outside.Disk 1 is between turntable 9 and the clamper 10 when rotated, and turntable 9 is integral rotation with clamper 10 and spindle motor 2.During disk 1 high speed rotating, because the distortion of insulating part 7, so the low degree of frequency when adjusting to the resonant frequency of base 6 vibrations than disk 1 high speed rotating.

Fig. 8 is near the cut-open view at the positions spindle motor 2, and it expresses the thin portion with the clamper 10 assembling all-in-one-piece balanced devices of disk set top.The yoke of being made by metallicl magnetic material 11 is fixed on the turntable 9, so that itself and spindle motor 2 rotate with being integral.Clamper 10 contains a magnet 27, and disk 1 is resulted from the magnetic adsorbability effect of the magnetic flux between magnet 27 and the yoke 11, so disk 1 can rotate with them with being integral.In order to make the production run simplification and to use for simplicity, normally dipole is magnetized for the magnetized surface 28 of magnet 27.Label " 15 " is the rear magnetic yoke (back yoke) of metallicl magnetic material, it is fixed on the unmagnetized surface 29 of a magnet 27 by suction type, the magnetic flux that spills from other place beyond the magnetized surface 28 with blocking-up, thus the suction efficient of disk 1 improved.Clamper 10 has comprised two magnetic balls 13 that can roll at least.Label " 13a " and " 13b " be illustrated respectively in the high speed rotating process and the low speed rotation process in the position of ball 13, this ball is divided into right half and left half in the accompanying drawings.These parts that constitute balanced devices are installed in by on insulating part 7 and the base 6 that main basal base 8 links to each other.As mentioned above, during disk 1 high speed rotating, since the distortion of insulating part 7, the low degree of frequency in the time of should adjusting to the resonant frequency of base 6 vibrations than disk 1 high speed rotating.

Fig. 9 is illustrated in the disk high speed rotating process, and owing to the view of unbalanced situation has been eliminated in the motion that is arranged on the ball 13 in the clamper 10, and this figure is the cut-open view of looking from the top.

With reference to Fig. 8 and Fig. 9, this two width of cloth figure has done explanation to the state of unbalanced disk 1 relevant ball 13 in the low speed rotation process.And to disk 1 explanation has been done in relevant unbalanced elimination in the high speed rotating process.

For CD-ROM drive, disk 1 with at a high speed (8 times of fast modes, maximum (top) speed is about 4,200rpm) rotation is transmitted fast so that realize data when read data.On the other hand, for example, in order to carry out voice playing, disk is by rotating with rated rotational frequency (about 200-500rpm).Therefore, the high speed rotating scope reads as data, and the low speed rotation scope, is simultaneous as voice playing.

When unbalanced disk 1 at it on axle during with high speed rotating, unbalanced force 18 is exactly the centrifugal force that affacts on the center of gravity 17 of disk 1, and this action direction is with disk 1 rotation.This unbalanced force 18 makes insulating part 7 distortion, so that base 6 rotations are swung with the gyro frequency of disk 1 simultaneously.As mentioned above, because the resonant frequency of base 6 vibrations is adjusted to the gyro frequency that is lower than disk 1, so always the direction with unbalanced force is opposite for the sense of displacement of base 6.Therefore, 2 balls 13 are set at least in clamper 10, can produce motoricity 22 during rolling, it is a centrifugal force 19 and the making a concerted effort of the resistance 21 that trends towards leaving rolling surface 20 directions, and this is made a concerted effort to promote ball 13 and rolls on rolling surface.The result makes ball 13 leaving the direction motion of swing-rotation center 23, and converges on the reverse direction with unbalanced force 18, and is last, because the gross mass of the ball 13a after converging, the inequality of disk 1 weighed be cancelled.

On the other hand, in the low speed rotation scope, as rated rotational frequency, the centrifugal force 19 of ball 13 is big inadequately, so that ball 13 is pulled on the rolling surface 20 and on rolling surface locatees, thereby cause the instability of ball, then can send unnecessary noise, as fricting movement sound between the inner surface portion of rolling sound, ball 13 and the clamper 10 of ball 13 and the clash between the ball 13.Take place for fear of these situations, make ball 13 with metallicl magnetic material.In addition, utilize the leakage flux 24 of

magnet

27 or 15 magnetic flux 25 from magnetized surface 28 to rear magnetic yoke, make the direct adsorbing sphere 13 of outer circumference surface 26 energy of magnet 27 or rear magnetic yoke 15, thereby they stably are positioned on the position of ball 13b, can prevent above-mentioned unnecessary noise like this.

Yet, when disk 1 when high speed rotating is converted to low speed rotation rapidly, said structure has following problem:

For some CD-ROM disk, data and sound are to be present in simultaneously in the disk usually.When this disk playback time, following situation can occur: after just fetching data with high speed reads, rotating speed just drops to rated rotational frequency, so that play sound.That is to say that disk promptly is converted to low speed rotation with high speed rotating the time, and then must carry out the broadcast of sound.

As mentioned above, when high speed, ball 13 is integral rotation with clamper 10, is pulled to simultaneously on the rolling surface 20, to offset the unbalanced of disk 1.But, when rotating speed drops to desired speed, because the effect of the leakage flux 24 of magnet 27, or because the effect of 15 magnetic flux 25 from magnetized surface 28 to rear magnetic yoke, make the centrifugal force that acts on the ball 13 big inadequately, so that these balls 13 are by the outer circumference surface 26 of magnet 27 or rear magnetic yoke 15 absorption.But as mentioned above, the magnetized surface 28 of magnet 27 is that dipole is magnetized.Have following feature under the magnetized situation of this dipole: leakage flux 24 is bigger, and the magnetic flux density of magnetic flux 25 is less simultaneously.Therefore, when disk 1 when low speed rotation is converted to high speed rotating, ball 13 is difficult to separate with the outer circumference surface 26 of magnet 27.On the contrary, when disk 1 when high speed rotating converts low speed rotation to, the outer circumference surface 26 of magnet 27 is difficult to adsorbing sphere 13, this is because ball 13 can not separate with rolling surface 20, unless the centrifugal force 19 that affacts on the ball 13 is very little.As mentioned above, when being transformed into voice playing after disk comes reading of data by high speed rotating, because above-mentioned ball 13 is difficult to characteristics such as separation and absorption, ball 13 is adsorbed by the outer circumference surface 26 of magnet 27 after beginning to read voice data at once.Collision during absorption passes to disk 1, thereby causes read error.

In addition, in the rotation initial procedure, promptly just started in the process of rotating at disk, rotating speed become very high after, ball separates with magnet and collides with rolling surface, why can be like this: because the effect of bigger leakage flux 24 makes ball 13 be difficult to separate with the outer circumference surface 26 of magnet 27 because the cause of following characteristic is arranged.Therefore, total impact force is bigger, thereby causes for example defective of the overlong time of starting rotation.

Disclosure of an invention

Goal of the invention

Consider the problems referred to above, the purpose of this invention is to provide a kind of disk set, this device is (the unbalanced problem that relates to disk) in the high speed rotating process, utilize the centrifugal force of ball to offset the unbalanced of disk effectively, and when low speed rotation such as voice playing, prevent unnecessary noise by the positioning stablityization that makes ball, in addition, during when being converted to low speed at a high speed or in the starting rotation, can not cause wrong the generation at the rotating speed of disk.

Summary of the invention

In order to address the above problem, disk set of the present invention comprises: can effectively offset the unbalanced balanced device of disk for one, this balanced device is adjusted to and can be rotated with the disk of assembling with being integral, and has hollow and annular parts that comprise a magnetic material; And a field generator for magnetic, be used for fixing this magnetic material by suction.At least a structure under this disk set also comprises in the array structure (1) to (3):

(1) this field generator for magnetic is a magnet, and it is positioned at the inner circumferential side of hollow and annular parts and utilizes polarization to make it to be magnetized to four utmost points or the more utmost point along sense of rotation;

(2) this field generator for magnetic is a magnet, and it is positioned at the inner circumferential side of hollow and annular parts and utilizes polarization to make it to be magnetized along the direction of turning axle;

(3) this field generator for magnetic is a magnet, and it is positioned at the inner circumferential side of hollow and annular parts and utilizes polarization to make it radially to be magnetized.

In the present invention, magnet as field generator for magnetic is to utilize polarization to be magnetized into four utmost points or magnetizing assembly more multipole or turning axle direction or radial direction polarization along sense of rotation, like this, just reduce to make magnetic material to be subjected to the effect of magnetized leakage flux, offset the unbalanced of disk effectively.In the present invention, even under the situation of disk low speed rotation, the centrifugal force that affacts on the magnetic material is also very little, because the leakage flux of magnet makes the motion instability of magnetic material, magnetic material is difficult to be subjected to the effect of leakage flux, thereby can stably offset the unbalanced force of disk.

Detailed description of the present invention

To describe several embodiments of the present invention with reference to the accompanying drawings.In addition, for the composition of each following embodiment, the parts identical with above-mentioned conventional apparatus adopt identical label.

The simple declaration of accompanying drawing

Fig. 1 comprises near the side view and (b) planimetric map of the magnet of the disk set of one embodiment of the invention (a) spindle motor;

Fig. 2 is in the motion of ball and the time comparative graph between beginning to read;

Fig. 3 is near the side view of spindle motor of the disk set of another embodiment of the present invention;

Fig. 4 is near the side view of spindle motor of the disk set of another embodiment of the present invention;

Fig. 5 is the horizontal cross of the interior clamper of the device of Fig. 4;

Fig. 6 is the vertical schematic sectional view of the interior clamper of the device of Fig. 4;

Fig. 7 is the skeleton view of traditional magnetic disk device;

Fig. 8 is near the sectional view of spindle motor that the traditional magnetic disk device of a balanced device is arranged;

Fig. 9 is the horizontal cross that is illustrated in the balanced device effect in the traditional magnetic disk device;

Figure 10 be in the magnetized disk set of dipole leakage flux to the horizontal cross of the effect of ball.

(magnetization of four utmost points)

Fig. 1 represents the first embodiment of the present invention, and wherein Fig. 1 a is a cut-open view, and Fig. 1 b is the planimetric map of magnet.

Label " 13 " is the ball that magnetic material is made, and has a plurality of balls to be placed in the clamper 10, and these balls can be rolled, to offset the unbalanced of disk 1.Position when label " 13a " expression ball 13 is in high speed rotating, and label " 13b " expression ball 13 is in low speed rotation and the position that is in when stopping.Label " 27 " is a magnet, and its magnetized surface 28 is extremely magnetized by four, thereby leads to the magnetic circuit of yoke 11 and attract this yoke 11 that disk 1 is between magnet 27 and the turntable 9 by formation.In Fig. 9 of the above-mentioned dipole magnetization configuration of expression, it respectively is 180 ° the S utmost point and the N utmost point that the circumference of magnet 27 is divided into.On the other hand, for four utmost points among Fig. 1 b magnetization, the S utmost point and the N utmost point are along the circumferential direction to go up totally to be divided into four utmost points, whenever very 90 ° and staggered.The magnetic attraction of 27 pairs of yokes 11 of magnet should be identical with the magnetized magnetic attraction of dipole.Label " 15 " is a rear magnetic yoke, make it fixing by it being adsorbed onto non magnetic surperficial 29 of magnet 27, and the rear magnetic yoke external diameter is more many greatly than the external diameter of magnet 27.The magnetic flux that label " 24 " representative spills from magnet 27, label " 25 " representative be 15 magnetic flux from magnetic surface 28 to rear magnetic yoke.

In having the first embodiment of the present invention of said structure, explained the appropriate authority that disk 1 rotates when high speed or low speed.

Similar to above-mentioned traditional disk set shown in Figure 9, if disk 1 is in the high speed rotating process, for example in data read process, show when unbalanced, come the centrifugal force 19 of self-swinging-rotation center to act on the ball 13, thereby ball 13 is pushed on the rolling surface 20, roll simultaneously, converge in then along unbalanced side and go up in the opposite direction with disk 1, and stop at the balance unbalanced force the position on, after this rotate with clamper 10 with being integral, thereby having offset the unbalanced of disk 1.

On the other hand, when the rotation of disk 1 when being converted to low speed (as voice playing) at a high speed, the centrifugal force that acts on the ball 13 becomes very little, make ball 13 leave rolling surface 20, then, because the effect of the leakage flux 4 of magnet 27 or because the effect of 15 magnetic flux 25 from magnet 27 to rear magnetic yoke makes ball 13 by the external peripheral surface 26 of magnet 27 or adsorbed by rear magnetic yoke 15.

In addition, for the foregoing description, because the magnetized surface 28 of magnet 27 is four extremely magnetized, so the state of magnetic flux is such: comparing with the magnetized situation of dipole, near the external peripheral surface 26 of magnet 27 leakage flux 24 is much smaller, and the magnetic flux density of 15 magnetic flux 25 is bigger from magnetized surface 28 to rear magnetic yoke.As a result, ball 13 will move like this: compare with the magnetized situation of dipole, ball 13 is easy to separate with magnet 27 or adsorbed by magnet 27.When the rotation of disk 1 rapidly when dropping to low speed at a high speed, above-mentioned characteristic can be adsorbed ball 13 with the short period by magnet 27.That is to say that because ball 13 was adsorbed, the collision of ball 13 is finished before being transformed into the voice data read mode, not taking place so do not have data read errors.In addition, because leakage flux 24 is also less, so the collision that causes when adsorbing sphere 13 is lighter.

In addition, when beginning to rotate, ball 13 is easy to separate with magnet 27, so the time of separating is shorter, this is owing to will be significantly smaller than impact under dipole magnetization situation with the impact of rolling surface.Therefore, the factor that makes the mistake (as servo slip) then alleviates greatly.

Fig. 2 is the curve map of the expression first embodiment function.In the last figure of this accompanying drawing (A), express in the characteristic of using under the balanced device situation, this balanced device has utilized the four extremely magnetized magnet of the foregoing description, figure (B) is illustrated in the characteristic of using under the conventional equalizer situation, and this balanced device has utilized the magnetized magnet of dipole.In each curve map, label " 33 " expression voice data reads the starting point of (reading signal), the intensity that label " 34 " expression is collided the trail-and-error signal (trail-and-error signal) that causes by ball 13 and magnet 27.Label " 35 " expression spindle motor 2 (spindle motor V _MSignal) change in voltage, and the sloping portion of this variation 35 is represented from the fringe time of high speed to low speed.The collision time that position between these

labels

33,34 and 35 relation will help to understand ball 13 and magnet 27 with read a little in the situation subaudio frequency data of the quick change of revolution of disk 1 initial between time relationship.

Compare mutually with the curve (A) of Fig. 2 with (B), the result is as follows: for the dipole magnetization balanced device of curve (B), from at a high speed to the fast transition process of low speed, ball 13 is so slow by the time that magnet 27 adsorbs, so that ball 13 is more late than the time of beginning reading of data with the collision of magnet 27.Therefore, trail-and-error signal (being the factor that causes voice data play mode mistake) degree is very strong.On the other hand, for four utmost points magnetization balanced device of curve (A), ball 13 carried out from changing to low speed at a high speed simultaneously with separating with disk 1 of rolling surface 20, and they are adsorbed by magnet 27 then.Therefore, the strong degree of trail-and-error signal is to appear at before voice data reads, so mistake can not occur.

(utilize vertically or magnetization that the mode of radial polarised is carried out)

Fig. 3-6 expression the present invention second and the 3rd embodiment.Structure same as the previously described embodiments adopts identical label to represent, and has omitted the detailed description that repeats.

In the embodiments of figure 3, have at least two balls 13 in clamper 10, to roll.Label " 13a " is represented the position of ball 13 when high speed or low speed rotation, and label " 13b " is represented the position of ball 13 under still-mode.The whole magnetized surface 28 of magnet 27 is polarized into the identical utmost point (in the drawings for the S utmost point), and unmagnetized whole surperficial 29 be polarized into the utmost point (the N utmost point) opposite with magnetized surface 28.In other words, magnet 27 is magnetized by the direction polarization along the vertical rotating shaft of clamper 10.As a result, formed the magnetic circuit that leads to yoke 11 that is used to attract yoke 11, thereby disk 1 can have been put between magnet 27 and the turntable 9.Adjust to the magnetic attraction size that magnet 27 acts on the yoke 11 identical with the magnetized suction of dipole.Label " 24 " is represented the leakage flux of magnet 27.

For the embodiment of Fig. 4-6, magnet 27 is magnetized by the mode of radial polarised.In the plane of upper surface side, promptly in the unmagnetized surface of magnet 27 29 sides, as shown in Figure 5, a N utmost point and a S utmost point are arranged in inner peripheral surface side and outer circumference surface face side respectively with one heart.As Fig. 6 a schematically expressed, the face side of magnet 27 and the polarity of rear side were opposite.This shows that the S utmost point and the N utmost point are arranged in the inner circumferential side and the outer circumference surface side of magnetic surface 28 respectively with one heart.In addition, even being done opposite layout (shown in Fig. 6 b), the S utmost point and the N utmost point also can realize identical functions.

When magnet 27 in a manner described vertically or radial polarised, near the leakage flux 24 the rolling surface 20 of magnet 27 is very little.Therefore, ball 13 can be subjected to the influence of leakage flux hardly, even also is so under the situation that centrifugal force reduces, and so just can offset unbalancedly, and this situation to high speed rotating is similar.In addition, when the starting rotation, ball 13 beginnings are being rolled on rolling surface 20 at a terrific speed, and the impact of ball 13 and rolling surface collision will be significantly smaller than the impact under the magnetized situation of dipole.Therefore, can significantly reduce the factor that leads to errors, as servo slip etc.

Figure 10 represents for the traditional magnetic disk device, the effect of 27 pairs of balls 13 of the magnetized magnet of dipole.When in low speed rotation, demonstrate unbalanced disk, (Figure 10 a) when rotated as double speed (Twiee-fast) DVD, act on centrifugal force 19 on the ball 13 less than the centrifugal force when the high speed rotating, with regard to being difficult to ball 13 is moved along the direction of offsetting unbalanced force like this.In addition, when high speed rotating (shown in Figure 10 b), the leakage flux 24 of magnet 27 is too big, can not cross magnetic flux barrier 24a motion to cause ball 13, thereby can't offset unbalanced.

Draw above-mentioned situation and compare, when can not be radially or when axially polarizing, leakage field 24 be by little, so that can not address the above problem.In addition, leakage flux 24 is present on the whole circumference face of magnet 27 very equably, so the magnetic flux that can not occur occurring when similar above-mentioned dipole magnetizes (Figure 10 b) hinders 24a, like this, ball 13 can along the circumferential direction be moved reposefully.

In addition, use magnetization technology vertically of the present invention or radial polarised that the identical effect of above-mentioned four extremely magnetized embodiment with Fig. 2 (A) can be provided.

Application industrially

As mentioned above, disk set of the present invention in addition when the rotation of unbalanced magnetic disc high speed also Can realize stable playback and data record, and can prevent from (playing such as audio frequency in low speed rotation During pattern) unnecessary noise appears, in addition, changing in the Rotation Process fast, can also lead to Cross the collision time that shortens ball and magnet or rolling surface, or by suppressing since collision bring Impact prevents mistake, and is long etc. such as read error and starting rotational time.

Claims

1. disk set comprises: a balanced device, this balanced device are arranged to and can be rotated with the disk of assembling with being integral, and have hollow and annular parts that comprise a magnetic material; And a field generator for magnetic, be used for fixing this magnetic material by suction;

Wherein this field generator for magnetic is a magnet, and it is positioned at the inner circumferential side of hollow and annular parts and utilizes polarization to make it to be magnetized to four utmost points or the more utmost point along sense of rotation.

2. disk set comprises: a balanced device, this balanced device are arranged to and can be rotated with the disk of assembling with being integral, and have hollow and annular parts that comprise a magnetic material; And a field generator for magnetic, be used for fixing this magnetic material by suction;

Wherein this field generator for magnetic is a magnet, and it is positioned at the inner circumferential side of hollow and annular parts and utilizes polarization to make it to be magnetized along the direction of turning axle.

3. disk set comprises: a balanced device, this balanced device are arranged to and can be rotated with the disk of assembling with being integral, and have hollow and annular parts that comprise a magnetic material; And a field generator for magnetic, be used for fixing this magnetic material by suction;

Wherein this field generator for magnetic is a magnet, and it is positioned at the inner circumferential side of hollow and annular parts and utilizes polarization to make it radially to be magnetized.