JPS6087468A - Rotation controlling device of disk - Google Patents

Abstract

PURPOSE:To reduce vertical vibration quantity of a disk by driving once the disk by a disk driving part so that speed of the disk will become higher than the prescribed revolving speed, then switching the disk to a servo circuit to control the speed of the disk to the prescribed revolving speed. CONSTITUTION:An operation of a disk driving part 10 causes a changeover switch 32 on a switching controller 30 to bring into connecting relation shown by a full line in the figure (a contact 32A is being connected to a contact 32C), and a disk motor 11 is driven so as to become high speed rotation because a driving signal 33 of a high speed driving circuit 22 of a driving controller 20 is inputted to the disk motor 11. However, the connecting relation of the changeover switch 32 is switched to the position shown by a dotted line in the figure (the contact 32A is being connected to a contact 32B) when the prescribed period set by a timer circuit 31 expires, and therefore the disk motor 11, which has been rotating at high speed by the high speed driving circuit 22 for the prescribed period, becomes a driving signal 33 from a servo circuit 21, and is rotated and controlled so that its revolving speed will be rated one.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a disk device, in which a disk is held in a holding section in a disk drive section and rotates in a predetermined manner. The present invention relates to a disk rotation control device that can reduce the amount of vertical runout.

[Background of the invention]

Conventionally, with respect to an optical disc held in a holding part in a disc drive part and rotating at a predetermined rotational speed, an objective lens in a playback output detection part is moved in the focusing and tracking directions to control its position, and the optical disc is passed through the objective lens. 2. Description of the Related Art Disk devices are known in which information is recorded on or reproduced from a disk using a source beam.

However, due to this device, the movable range of the objective lens in the reproduction output detection section in the focus direction is ±1.
Since the range of about 5n is selected, if the vertical deflection of the disk (the amount of variation in the focus direction) caused by disk deflection or warping becomes larger than the movable range, the objective lens cannot be focused. However, as a disk device, there is a major problem in that it results in poor recording and reproducing operations.

Particularly, in the case of a disk having a diameter of about 30 cm, the outer circumferential portion of the disk tends to warp and sag due to its own weight, which tends to increase the amount of vertical runout of the disk.

In addition, even if the vertical runout of the disk is within the movable range of the objective lens, generally speaking, the greater the amount of variation from the objective lens reference position, the lower the required sensitivity and characteristics during recording and playback, and the performance will be affected. In order to avoid deterioration, the smaller the amount of surface run-out, the better. When controlling the rotation of the disk, after the disk is held at a predetermined position in the disk attachment part, the disk should be driven to a predetermined rotation speed. Control is performed by a servo circuit section.

A predetermined number of rotations (1800 in the case of optical method) is applied to the amount of vertical runout due to warpage and deflection when the disk is stopped.
r, p, rn), the amount of vertical runout is reduced due to the centrifugal force generated by the rotation, but if the rotation is simply performed at a speed of 1 degree at a predetermined rotational speed, sufficient vertical runout is not achieved. You won't get dragon reduction.

Therefore, it has been strongly desired to further reduce the amount of vertical runout of the disk and achieve good recording and reproducing characteristics.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art as described above, and to provide a disk that is capable of reducing the amount of vertical runout of a disk that is held in a holding section in a disk drive section of a disk device and rotates at a predetermined number of rotations. An object of the present invention is to provide a rotation control device.

[Summary of the Invention] According to the findings of the present inventors, in the characteristic showing the relationship between the disk rotational speed of the disk rotated by the disk drive unit and the amount of vertical runout of the disk, the disk rotation The change characteristics of the amount of vertical runout of the disk when the number is changed from low speed (including stopped state) to high speed rotation (about 15 times the specified rotation speed 11300y, 7+, m) and vice versa. A so-called hysteresis characteristic occurs between the change characteristics of the disk vertical runout amount when the rotation speed is changed, and the change characteristics of the disk vertical surface runout amount when the rotation speed is shifted from high speed rotation to low speed rotation are It has been found that the variation characteristic of the amount of vertical runout of the disk is generally reduced when changing from low-speed rotation to high-speed rotation.

The present invention makes use of this phenomenon.

In other words, in order to reduce the amount of vertical runout of the disk at the rated rotational speed, the hysteresis characteristic of the relationship between the disk rotational speed and the amount of vertical runout of the disk is used, and the disk is mounted in the holding section within the disk drive unit. After the disk is held, the rotation of the disk is controlled by the servo circuit from the beginning to a predetermined rotation speed. After the disk is once driven to a high speed exceeding a predetermined number of rotations by the servo circuit, the servo circuit is then switched to control the disk to a predetermined number of rotations to reduce the amount of vertical runout of the disk. As a feature, furthermore,
Disc shape (20 crn diameter disc and 30 cM
If the diameter of the disk changes significantly, the predetermined time for high-speed rotation set by the timer circuit is changed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a system block diagram showing a disk rotation control device as an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing temporal changes in the quantities (disk rotation speed and disk vertical runout amount) in FIG. 1. , Figure 3 is a characteristic diagram showing the relationship between the disk rotational speed and the vertical runout of the disk, and Figure 4 shows the relationship between the disk rotational speed and the disk vertical runout when the high-speed operation time is changed due to changes in the disk shape. FIG. 3 is a characteristic diagram showing the relationship with quantity.

In these figures, 1 is a disk, 10 is a disk drive unit, a disk motor 11, a turntable 1.
2, a holding section 13, etc.

Reference numeral 20 denotes a drive control section, which is composed of a servo circuit section 21 for controlling the disk drive section 10 and the disk 1 to a rated rotation speed, and a high-speed 1 drive circuit section 22 for rotating at a high speed higher than the rated rotation speed. has been done.

Reference numeral 30 denotes a switching control section, which includes a changeover switch section 32 that is controlled by a timer circuit 31. Reference numeral 33 denotes a drive signal for the disk motor 11, and 40 a detection section, which is composed of an objective lens 41, an actuator 42, a detector 43, and the like. 44 detection signals, 45 a detection circuit, 46 a control circuit, 50 guide parts, 60 a system control part, 70 disc rotation speed characteristics according to the control method of the present invention, 71 conventional disc rotation speed characteristics, 75 76 is the negative vertical runout characteristic of the disk according to the control method of the present invention, 80 is the change in the amount of disk vertical runout when the rotational speed of the disk 1 is changed from a high speed state to a low speed state. Characteristics, 81 is the change characteristic of the disk vertical runout when the rotational speed of the disk 1 is changed from a low speed state to a high speed state, 90ii is a negative characteristic of the disk vertical surface runout in the 30 crn disk 1, and 91 is the disc top surface runout characteristic in the 20 crn disk 1. It has a negative downward runout characteristic.

Next, the operation will be explained.

In the disk drive shown in FIG.
1 is controlled to the rated rotational speed by means of a drive signal from the servo circuit section 21. Therefore, the actuator 42 is driven by the detection signal 44 from the detector 43 through the detection circuit 45 and the control circuit 46 for the disk drive section 10, that is, the disk 1 rotating at the rated rotation speed. The detection unit 4 controls the objective lens 41 in a well-known focus and tracking direction.
The original beam at 0 is appropriately controlled on the information track portion of the disk 1 to record or reproduce information signals.

Note that in the detection section 40, a detector 43 is held by a guide section 50, and the detection section 40 can be moved in the radial direction of the disk 1 by a drive mechanism (not shown) that moves the detection section 40 in the radial direction of the disk 1. Therefore, it is possible to access any information track portion of the disc 1.

Here, considering the amount of vertical runout of the disc 1, in the conventional rotation control method of the disc drive unit 10, after the disc 1 is mounted on the turntable 12 and held by the holding unit 13, the rotation speed is initially set to the rated rotation speed. Since it is controlled by the servo circuit section 21, the disk rotation speed characteristic 7 shown in FIG.
As shown in Figure 1, after startup, the rotation speed is controlled to converge to the rated speed, so in the characteristics of the vertical runout amount of the disk against the disk rotation speed shown in Fig. 3, when the disk rotation speed changes from low to high speed, The amount of disk vertical surface runout (A
1) However, it is difficult to significantly reduce the amount of runout of the disk's vertical surface at around the rated rotational speed. Incidentally, the change in the amount of excavation on the upper and lower surfaces of the disk after startup is as shown in the characteristic 76 shown in FIG.

Therefore, in order to reduce the amount of vertical runout of the disk 1, the present invention provides a hysteresis characteristic in the characteristics between the rotational speed of the disk 1 and the amount of vertical runout of the disk shown in FIG. Disk vertical surface runout 31% when controlled from low speed rotation to high speed rotation starting from a held stopped state 81, negative characteristic of disk vertical surface digging when returning from high speed rotation to low speed rotation 80
This is done by taking advantage of the fact that when compared at the same rotation speed, the negative vertical runout characteristic 80 of the disk becomes smaller when returning from high speed rotation to low speed rotation.

According to experiments, the rated rotation speed (
Disk vertical runout 1 (AI) when controlled to 18QOr, pom by optical method, and disk vertical surface when disk 1 is driven at high speed about 1.4 times the rated rotation speed and then returned to the rated rotation speed. The relationship with the runout amount (A2) is A 2 ”
,,A I

Here, in the disk rotation control device of the present invention, as shown in FIG. By providing a circuit section 21 and a high-speed drive circuit section 22 for high-speed rotation above the rated rotation speed, and controlling the disk drive section 10 from the system control section 60 via the switching control section 30, This effectively utilizes the hysteresis characteristic of the amount of vertical runout of the disk described above.

That is, after the disc 1 is mounted on the turntable 12 and held by the holder 13, various operations are performed by operating the system control unit 60 (for example, playback operation, etc.), but the disc drive unit 10, the changeover switch section 32 in the changeover control section 30 has the connection relationship shown by the solid line in the figure (the state in which the contacts 52A and 320 are connected).
Since the drive signal 33 from the high-speed drive circuit section 22 of the drive control section 20 is input to the disk motor 11, the disk motor 11 is driven to rotate at a high speed.

From the force, the timer circuit 3 in the switching control section 60
1 is engaged simultaneously with the operation of the system control unit 60, and when a predetermined time set by the timer circuit 31 has elapsed, the timer circuit 31 switches the connection relationship of the changeover switch unit 32 to the position shown by the dotted line in the figure (contact 52A). And 3271?
connected state) for a predetermined period of time,
The disk motor 11, which was being rotated at high speed by the high-speed drive circuit section 22, receives the drive signal 3 from the servo circuit section 21.
5, the rotation is controlled 1lIII to reach the rated rotational speed, and the hysteresis characteristic of the amount of runout of the upper and lower surfaces of the disk can be utilized to reduce the amount of image of the upper and lower surfaces of the disk.

That is, as shown in FIG. 2, the disk motor runs for a predetermined time (time in Xi) set by the timer circuit 31 from the start of rotation (START), and the disk rotation speed characteristic 7
0 performs high-speed rotation, and then (time after X) is controlled to the rated rotation speed. Characteristic 7. The disk motor 11 is controlled to the rated rotation speed at the time indicated by Y in the figure. becomes. The change in the amount of vertical runout of the disk at this time is determined from the hysteresis characteristic shown in FIG. 9. The amount of play on the upper and lower surfaces of the disk can be significantly reduced.

According to experiments, a predetermined high rotation speed (approximately 25 aor,
The predetermined time (a) until driving to p-m) is about 15~
It takes about 20 seconds and is not a particular problem.

Next, Figure 4 shows that when different disk shapes are installed, such as disk diameters of 20 hundred and 30 tsuba, the inertial force of the disk is small (20 rust compared to the disk diameter of 30. 2), the setting time of the timer circuit 31 is shortened, and the time required to reach the rated rotation speed is shortened.

That is, after a disk with a diameter of 30 mm is held in the disk drive unit 10, the characteristic 90 of the amount of vertical runout of the disk at the time set by the timer circuit 31 for high-speed rotational drive (time up to xl) , the characteristic 91 of the amount of vertical runout of the disk during the time set by the timer circuit 31 (time up to When the force is small, it is possible to reduce the amount of runout in the upper and lower surfaces of the disk and to shorten the control time to reach the rated rotation speed.

Note that it is possible to detect the disk diameter by providing a selection switch section in the system control section 60 and to switch the setting time of the timer circuit using a well-known technique.

Furthermore, when the disk diameter is 21]y++, even if the disk diameter is 30 eM, there is no problem even if the disk diameter is 30 eM, and there is no problem because the rotation speed of the disk 1 becomes higher. The amount of reduction in the amount of vertical runout of the disk is expanded.

Furthermore, although the embodiments are described as an optical disk device, it goes without saying that similar effects can be obtained with other types of disk devices (eg, electrostatic capacitance type, etc.).

〔Effect of the invention〕

As described above, in the disk rotation control device of the disk device according to the present invention, after the disk is held in the disk drive section, for a predetermined period of time set by a timer circuit or the like,
After driving the disk to high speed rotation above the rated rotation speed, switch control so that the rotation speed reaches the rated rotation speed is fl1.
It is possible to significantly reduce the vertical runout of the disc with a simple method, and the detection performance of the detection section can be greatly improved, so the recording and reproduction characteristics of information signals are improved. Conventionally, even in cases where the amount of vertical runout of the disk was greater than the detection characteristics of the detector and recording and reproducing information signals was impossible, it is now possible to record and reproduce information signals favorably. What excellent characteristics does it have?
It is possible to provide a high-performance, highly functional disk device.

[Brief explanation of the drawing]

FIG. 1 is a system block diagram showing a disk rotation control device of a disk drive as an embodiment of the present invention, FIG. 2 is a characteristic diagram showing changes in disk rotation speed and disk vertical runout amount, and FIG. FIG. 4 is a characteristic diagram of the amount of vertical runout of the disk as a function of the disk rotation speed. FIG. 1... Disk 10... Disk drive section 11...
・Disk motor 2]]... Drive control section 21...
Servo circuit section 22... High speed drive circuit section 30... Switching control section 31... Timer circuit 32... Changeover switch section 40... Detection section 60... System control section 70... Present invention Disk rotation speed custom made at 75...disk vertical runout amount characteristics rf diagram in this invention Brown 2 Figure 1 Rotation rjJ rotation number

Claims (1)

[Scope of Claims] D. In a disk device configured to record or reproduce information on a disk that rotates at a predetermined number of revolutions per unit time, the disk is started up from zero speed at startup. a first disk drive control means for guiding the disk rotating at a high rotation speed to a high rotation speed; and a second disk drive for controlling the speed of the disk rotating at a high rotation speed to a predetermined rotation speed by reducing the speed to the predetermined rotation speed. A control means and a time limit means are provided, and after activation, the first disk drive control means is operated for a period set by the time limit means, and thereafter the second disk drive control means is operated. A disk rotation control device characterized in that switching is performed between the eleventh and second disk drive control means. 2. The rotation control device according to claim 1, wherein the set period in the time limit means is changed according to the shape and size of the disk.