JPH08115565A - Disk rotating control method in recorded information reproducing device - Google Patents

Abstract

PURPOSE: To control a disk in a constant linear velocity disk device without any overshoot or reverse rotation even when a spindle maximally accelerated/ decelerated with an open loop at the time of access. CONSTITUTION: A period T1 at an objective address is calculated at the time of access, and is compared with an output T2 of a period detecting means 14, and then when they are T1<T2 at the time of accelerating the spindle, a changeover means 13 is set to a max. acceleration means 11 in order to give the max. acceleration. Then, if T1>=T2, the changeover means 13 is set to a speed control means 9 for the purpose of control based on information recorded on a disk or the changeover means 13 is cut off to make the disk free run. On the other hand, at the time of deceleration, if T1<T2, the changeover means 13 is set to a max. deceleration means 12 so as to give the max. deceleration, and if T1<=T2, the changeover means 13 is set to the speed control means 9 for the purpose of control based on the information recorded on the disk or the changeover means 13 is cut off to make the disk free run.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk rotation control method for a disk drive device in which the linear velocity is constant.

[0002]

2. Description of the Related Art FIG. 5 shows an optical disk device having a constant linear velocity as an example of a conventional recorded information reproducing device. In FIG. 5, reference numeral 1 denotes a disk, which is driven by the spindle motor means 2. A pickup means 3 reproduces a recording signal on the disk 1 and also outputs a track cross signal. Positioning of the pickup means 3 is performed by driving the traverse motor means 4 according to a command from the traverse control means 5. While the pickup means 3 is moving by the traverse motor means 4, the microcomputer means 6 counts the track cross signal obtained from the pickup means 3 to measure the movement amount and sends the pickup means 3 to the target position. The reproduction signal obtained from the pickup means 3 is input to the rotation information detection means 7. The rotation information detecting means 7 detects a synchronizing signal from the recording signal on the disc 1. The frequency of this synchronizing signal becomes larger as the pickup means 3 is closer to the outer circumference when the disk having a constant linear velocity is rotating at a constant rotational angular velocity. The speed control means (including the phase control means) 9 compares the outputs (including the phase) of the reference frequency generation means 8 and the rotation information detection means 7 and sends a control amount according to the difference to the motor drive means 10. The motor driving means 10 drives the spindle motor means 2 according to the control amount. First, when the pickup means 3 is on the inner peripheral side and the disk is rotating at a constant linear velocity,
When the pickup means 3 moves to the outer peripheral side, the output of the rotation information detecting means 7 becomes larger than the output of the reference frequency generating means 8. Therefore, the control amount becomes a large negative value, and the spindle motor means 2 is driven in the decelerating direction. When the pickup means 3 moves from the outer peripheral side to the inner peripheral side, the opposite positive control amount is output. The maximum acceleration means 11 and the maximum deceleration means 12 are means for giving the maximum angular acceleration to the motor driving means 10 during acceleration and deceleration, and the switching means 13 is instructed by the microcomputer means 6.
Is configured to be controlled by switching.

The operation at the time of access of the optical disk device configured as described above will be described. A case will be described below in which, following the access command, the movement of the pickup means to the target position and the acceleration or deceleration of the disk to the target rotation speed are simultaneously started. FIG. 6 shows a processing procedure of the microcomputer means 6 at the time of access. When the microcomputer means 6 receives the access instruction in step 1, the number of tracks up to the target address is calculated in step 2 (this number of tracks is n1). The method of calculating the number of tracks n1 is obtained, for example, by the formula shown in (Equation 1).

[0004]

[Equation 1]

At this time, the moving direction of the traverse system is also determined. Then, in step 3, the microcomputer means 6 sets the switching means 13 in the state of FIG.
The motor drive means 10 is arranged so that the speed control means 9 always approaches the reference frequency generation means 8 while the rotation information detection means 7 detects the synchronization signal from the reproduction signal output of the pickup means 3 while the pickup means 3 is moving in response to the access command. Will be controlled in a closed loop. Next, in step 4, the microcomputer means 6 gives a movement command to the traverse control means 5. When the pickup means 3 starts to move by the traverse motor means 4, in step 5, the microcomputer means 6 causes the pickup means 3 to move.
The track cross signal output from the device is counted (this count value is set to n2), and compared with the number of tracks n1 calculated in advance, the count value is no more (n1 <= n2).
(Step 6), the traverse control means 5 is instructed to stop the traverse (step 7). As a result, the pickup means 3 is sent to the target radial position,
Rotation information detecting means 7 from the reproduction signal of the pickup means 3
Detects the synchronization signal and controls the motor drive means 10 by the speed control means 9 to establish the rotation speed of the spindle motor means 2. Then, the pickup means 3 detects the target address on the disc 1.

As described above, when the speed of the spindle motor means 2 is controlled based on the rotation information of the disk 1 during the traverse movement, the pickup means 3 is used.
, The difference between the output of the rotation information detecting means 7 and the output of the reference frequency generating means 8 becomes large, and the rotation control of the disk 1 can be performed at high speed. However, in actuality, the movement of the pickup means 3 does not rise rapidly at the beginning, so that there is a problem that the access is delayed due to the delay of the rise command of the disc speed control.

FIG. 7 shows a processing procedure for avoiding the above problems. When the microcomputer 6 receives the access command and the rotation control up to the target address is accelerated, the switching device 13 is switched to (c) of FIG. 5 in step 9 and the maximum acceleration command is given to the motor driving device 10 in an open loop. To do so. At the same time, the microcomputer means 6 gives a drive command to the traverse control means 5, and when the count of the track cross signal exceeds the target number of tracks, the switching means 13 is switched to (a) of FIG. The control of the drive means 10 is provided from the speed control means in a closed loop. On the other hand, when the rotation control up to the target address is decelerated, similarly, in step 10, the switching means 13 is switched to (b) of FIG. Thus, the rotation control of the disk can be processed at high speed.

[0008]

However, in the conventional device as described above, when the spindle is controlled in the closed loop based on the rotation information of the disk at the time of access, a delay occurs due to the rising command of the disk speed control. There is a problem of slow access. When the spindle motor means is maximally accelerated or decelerated in the open loop and the traverse arrives later than the establishment of the rotation of the spindle motor, the maximal acceleration causes the disk rotation to overshoot the target cycle. . This significantly raises the temperature of the spindle motor and the drive means. In addition, if the maximum deceleration is reached, there is a danger that the spindle motor will stop or rotate in the reverse direction, causing a runaway.

The present invention solves the above-mentioned problems of the prior art, and provides a device which can access at high speed without fear of overshoot during acceleration, rotation stop and reverse rotation during deceleration. The purpose is to

[0010]

In order to achieve the above object, the present invention has a motor means for rotating a disk having a constant linear velocity, a cycle detecting means for detecting a rotation cycle of the motor means, and recording on the disk. Picked-up means for detecting the detected information, rotation information detection means for detecting the rotation speed information included in the detection signal of the pickup means, and rotation of the motor means based on the speed information detected by the rotation information detection means. It comprises speed control means for controlling the speed and traverse means for positioning the pickup means at an arbitrary position on the disk in the radial direction, and when the target address is accessed, the target rotation of the motor means at the target address point. Cycle T1
And a step of supplying maximum angular acceleration in an open loop to the motor means until the output T2 of the cycle detecting means reaches the target rotation cycle T1, and the output T2 of the cycle detecting means is set to the target. When the rotation cycle T1 is reached, the rotation control of the motor means is performed by the speed control means,
Switching to a control loop composed of the pickup means and the rotation information detecting means.

Another method is to calculate a target rotation cycle T1 of the motor means at a target address point in accessing the target address, and until the output T2 of the cycle detecting means reaches the target rotation cycle T1. Supplying a maximum angular acceleration to the motor means in an open loop, and shutting off a control signal to the motor means when the output T2 of the cycle detecting means reaches the target rotation cycle T1. When the movement of the traverse means is stopped, it comprises a step of switching the rotation control of the motor means to a control loop composed of a speed control means, a pickup means and a rotation information detecting means.

[0012]

The present invention has the following actions due to the above-mentioned configuration. Since the rotation cycle of the spindle motor can be always detected at the time of access by the cycle detection means, if the spindle motor reaches the target cycle before the traverse ends by calculating the target rotation cycle, the spindle motor rotation control is performed. Even if the spindle motor is accelerated to the maximum, overshooting does not occur by switching to rotation control based on the recording signal of 1 or by cutting the control loop and rotating the disk by its own inertial force. Also, even if the maximum deceleration is performed, the rotation does not stop or the reverse rotation does not occur.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the present invention is shown in FIG. Since the device of this embodiment shown in FIG. 1 has basically the same configuration as the conventional device shown in FIG. 5, the same components are designated by the same reference numerals and detailed description thereof will be omitted. In FIG. 1, reference numeral 14 is a cycle detecting means for outputting a cycle signal proportional to the rotation cycle of the spindle motor means 2 so that the microcomputer means 6 can measure the time of the input pulse interval of the cycle to obtain the rotation cycle of the motor. Is composed of.

The operation at the time of access of the device configured as described above will be described. FIG. 2 shows a processing procedure of the microcomputer means 6 at the time of access. When the microcomputer means 6 receives the access command in step 1, the number of tracks up to the target address is calculated (this number of tracks is n1). The number of tracks n1 is calculated by the equation shown in (Equation 1) as in the conventional example. Further, the moving direction of the traverse system is also determined (step 2). Next, the target rotation cycle T1 of the spindle motor means 2 at the target address is calculated in advance. The method of calculating the target rotation cycle can be obtained, for example, by the formula shown in (Equation 2) (step 3).

[0015]

[Equation 2]

Next, in step 4, the acceleration / deceleration of the spindle is determined from the traverse movement direction. When the moving direction is from the inner circumference to the outer circumference, the spindle is decelerated, and when the movement direction is from the outer circumference to the inner circumference, the acceleration is determined. When the acceleration is determined in this way, the switching means 13 is set to the maximum acceleration means 11
If it is determined to be decelerating, the switching means 13 is set.
Is set in the maximum deceleration means 12 (step 5 or step 6). Next, in step 7, the microcomputer means 6 gives a drive command to the traverse control means 5.

When the traverse motor means 4 starts to move the pickup means 3, the microcomputer means 6 detects the spindle rotation cycle T2 obtained by the cycle detection means 14 (step 8), and then the pickup means 3 outputs it. The count value n2 of the track cross signal is detected (step 9). The process is repeated until each condition is satisfied, but first, in the spindle system, the determination process is different between the acceleration process and the deceleration process (step 1
0). In the case of acceleration, the cycle T1 calculated in advance and the detection cycle T2 are compared (step 11), and if T2> T1, the detection process is repeated, and if T2 <= T1, the switching means 13 is set to the speed It is set in the control means 9 (step 13). In the case of deceleration, similarly, T1 and T2 are compared (step 12), and if T2 <T1, the detection process is repeated, and if T2> = T1, the switching means 13 is set to the speed control means 9 because the target rotation cycle has been reached. set. On the other hand, in the traverse system, the number of tracks n1 calculated in advance is compared with the count value n2, and n2 <n
When it is 1, the detection process is repeated, and when n1 <= n2 (step 14 or step 15), the traverse control means 5 is instructed to stop the traverse (step 16) and the switching means 13 is simultaneously set to the speed control means 9. (Fig. 2:17). At this time, if the traverse system has not reached the target, or if the spindle system has reached the target, spindle rotation cycle detection is not performed, and only track cross signal count and determination processing is repeated. When the spindle system has not reached the target, the spindle rotation cycle is detected and the track cross signal is counted to repeat the determination process. When the traverse system reaches the target, the spindle system is switched to the speed control means at the same time as the traverse stop command, so that even if the spindle system has not yet reached the target at this time, it can be pulled into a predetermined rotation cycle. In this way, the pickup means 3 is sent to the target radial position, the rotation information detection means 7 detects a synchronization signal from the reproduction signal of the pickup means 3, and the speed control means 9 controls the motor drive means 10 in a closed loop. The number of revolutions of the spindle motor means 2 is established,
The pickup means 3 can detect the target address on the disc 1.

According to the first embodiment of the present invention described above, even if the spindle control during access is performed by maximum acceleration or maximum deceleration, the rotation based on the recording signal on the disk is reached when the target cycle is reached while detecting the rotation cycle. Since the control is switched to, there is no concern about overshoot at the time of maximum acceleration, rotation stop at the time of maximum deceleration, and reverse rotation unlike the conventional device.
Moreover, since the spindle is controlled by the maximum acceleration (deceleration) command, the rotation can be set earlier than the rotation control based on the recording signal on the disk.

FIG. 3 shows an access operation in the spindle acceleration direction. (A) shows the operation by the rotation control based on the recording signal on the disk by the conventional rotation control method. (B) shows a case where maximum acceleration is performed at the time of access by the conventional rotation control method. (C) shows the operation in the first embodiment of the present invention. (D) shows the operation in the second embodiment of the present invention. From this, it can be seen that rotation establishment is slow in (a), and in the method of (b) the spindle exceeds the target rotation speed before the traverse arrives, resulting in overshoot. (C)
Then you can see that it is enacted at the optimum speed. Further, comparing (b) and (c) with respect to the spindle speed control signal, it can be seen that (c) returns to a steady state faster and the temperature rise of the spindle motor can be small. However, in (c), when the traverse arrives much later than the target rotation speed of the spindle, when the output of the switching means is switched to the speed control means side when the spindle achieves the target cycle, the traverse is moving. Since the speed of the spindle is controlled by the signal on the disk at the position, the command signal to the motor drive means temporarily outputs a large reverse command in order to pull in the rotation speed at a point before the target. There is.

A second embodiment for solving such a problem will be described below. The configuration of the device in the second embodiment is the same as that of the device of the first embodiment shown in FIG. 1, and therefore detailed description will be omitted. However, switching means 1
When the connection of 3 is not provided in any of (a), (b) and (c), the motor drive means 10 automatically sets the spindle motor means 4 to the uncontrolled state (hereinafter, this state is referred to as the free-run state). It is assumed that the inertial force keeps a certain speed and keeps turning. FIG. 4 shows a processing procedure of the microcomputer means 6 at the time of access in the second embodiment. In FIG. 4, steps 1 to 12,
Steps 14 to 17 are exactly the same as the operation of the first embodiment. The only difference is step 13,
The switching means 13 is the maximum acceleration means 11 and the maximum deceleration means 1
2. This is a process of bringing the speed control means 9 into an open state that has no effect. As a result, when the spindle system is accelerated in step 11, the cycle T1 and the detection cycle T calculated in advance are calculated.
2 are compared, and if T2> T1, the detection process is repeated,
If 2 <= T1, it is determined that the target rotation cycle has been reached, and the switching means 13 is opened to free-run the spindle. On the other hand, if the spindle system is decelerating, step 12
Similarly, T1 and T2 are compared, and if T2 <T1, the detection process is repeated. If T2> = T1, it is determined that the target rotation cycle has been reached, and the switching means 13 is opened to free-run the spindle. When the traverse is completed, the switching means 13 is connected to the speed control means 9 in step 17. In this way, the spindle motor means 2 can maintain the target rotation cycle until the end of the traverse. Therefore, in FIG. 3C, when the spindle achieves the target cycle, the speed control means 9 temporarily gives a large reverse direction command. Is output, the spindle motor means 2 is not affected and a command signal to the motor driving means as shown in FIG. 3D is obtained, so that stable rotation control of the spindle motor can be performed.

According to the second embodiment of the present invention described above, even if the spindle control during access is performed by the maximum acceleration or the maximum deceleration in the open loop, the spindle motor means 2 is activated when the target cycle is reached while detecting the rotation cycle. By setting the free-run state, the target cycle can be maintained, and even if the speed control means 9 temporarily outputs an excessive reverse direction command, stable rotation control can be performed without affecting the spindle motor means 2.

As described above, in the embodiment of the present invention, the spindle control is performed in the open loop. For example, the target rotation cycle T1 calculated by the microcomputer means 6 is used.
When considering a method in which the target rotation cycle T1 can be pulled in a closed loop by comparing the rotation cycle T2 detected by the cycle detection means 14 with the rotation cycle T2, if this is performed by hardware, the speed is sent to the motor drive means 10. The second speed control means must be prepared as means for giving a control signal. In the case of using software, the speed control signal can be given by the microcomputer means 6 instead of the second speed control means, but in this case, the microcomputer means 6 always outputs the speed control signal to the motor drive means 10. Since it is necessary to calculate the value, the processing load on the microcomputer means 6 becomes large. Further, in the method according to the embodiment of the present invention, the resolution of the period detecting means 14 does not need to be so high and the accuracy is not required, so that an inexpensive magnetic encoder may be used instead of an expensive optical encoder. There are also merits.

In the first and second embodiments of the present invention, when the resolution of the cycle detecting means 14 is low, the traverse ends before the cycle is measured and detected in the access of a very short distance. There are cases. In such a case, when the number of traversing tracks calculated by the microcomputer means 6 is less than or equal to a certain number, the switching means 13 is set to the speed control means 9 from the beginning and the rotation control is performed based on the recording signal on the disk. It is desirable to access by.

Further, when the resolution of the cycle detecting means 14 is low, the output of the cycle detecting means 14 is delayed with respect to the actual rotation cycle, so that the target rotation cycle T1 is set so that the switching timing of the switching means 13 is advanced. It is good to adjust the value a little.

The number of tracks n1 calculated by (Equation 1) in the first and second embodiments of the present invention is such that the pickup means 3 moves between the time when the traverse system is given a stop command and the time when it is completely stopped. It is even better to reduce the overshoot amount from the number of tracks.

In the second embodiment of the present invention, when the spindle motor reaches the target cycle and makes the free run, the target rotation cycle T is taken into consideration in consideration of deceleration due to friction of the motor itself.
It is also effective to adjust 1 to some extent.

In addition, for example, in the case of a compact disc device or a CD-ROM device, in the second embodiment of the present invention, when the spindle motor reaches the target period and is in the free-run state, a traverse stop command is issued. At this time, the switching means 13 was switched from the cutoff state to the speed control means, but the free run may be switched to the speed control immediately after the traverse ends or after checking the subcode address after the traverse ends.

Although the lead screw system is shown as the traverse system feeding mechanism, a system combining gears,
Any other method such as a linear motor method or a swing arm method may be used.

Further, in the first and second embodiments of the present invention, the cycle detecting means may instead detect the number of revolutions.

[0030]

As described above, according to the present invention, the spindle control during access is performed by maximum acceleration or maximum deceleration, and the rotation control is switched when the target cycle is reached while detecting the rotation cycle. , The overshoot at the maximum acceleration is eliminated, and the temperature rise of the spindle motor can be suppressed. Also, there is no concern about rotation stop and reverse rotation at the time of maximum deceleration, and since the spindle is controlled by the maximum acceleration (deceleration) command, the rotation is established earlier than the rotation control based on the recording signal on the disk to speed up access. be able to.

[Brief description of drawings]

FIG. 1 is a configuration diagram of first and second embodiments of the present invention.

FIG. 2 is an explanatory diagram of a processing procedure in the first embodiment of the present invention.

FIG. 3 is an operation explanatory diagram in the first and second embodiments of the present invention.

FIG. 4 is an explanatory diagram of a processing procedure in the second embodiment of the present invention.

FIG. 5 is a block diagram of a conventional example

FIG. 6 is an explanatory diagram of a first processing procedure in a conventional example.

FIG. 7 is an explanatory diagram of a second processing procedure in the conventional example.

[Explanation of symbols]

 1 Disc 2 Spindle Motor Means 3 Pickup Means 4 Traverse Motor Means 5 Traverse Control Means 6 Microcomputer Means 7 Rotation Information Detecting Means 8 Reference Frequency Generating Means 9 Speed Control Means 10 Motor Driving Means 11 Maximum Accelerating Means 12 Maximum Decelerating Means 13 Switching Means 14 Cycle detection means

Claims (2)

[Claims] 1. A motor means for rotating a disk having a constant linear velocity, a cycle detecting means for detecting a rotation cycle of the motor means, a pickup means for detecting information recorded on the disk, and a detection by the pickup means. Rotation information detection means for detecting rotation speed information included in the signal, speed control means for controlling the rotation speed of the motor means based on the speed information detected by the rotation information detection means, and the pickup means for the disc. A method for controlling the rotation of a disk in a recorded information reproducing apparatus, which comprises a traverse means for positioning an arbitrary position in the upper radial direction, wherein a target rotation cycle of the motor means at a target address point in accessing a target address. The step of calculating T1 and the output T2 of the cycle detecting means Supplying the maximum angular acceleration in the open loop to the motor means until the cycle T1 is reached, and controlling the rotation of the motor means at the speed when the output T2 of the cycle detection means reaches the target rotation cycle T1. Switching to a control loop composed of control means, the pickup means, and the rotation information detection means,
A method of controlling rotation of a disk, comprising: switching the rotation control of the motor means to the control loop when stopping the movement of the traverse means. 2. Motor means for rotating a disk having a constant linear velocity, cycle detecting means for detecting a rotation cycle of the motor means, pickup means for detecting information recorded on the disk, and detection by the pickup means. Rotation information detection means for detecting rotation speed information included in the signal, speed control means for controlling the rotation speed of the motor means based on the speed information detected by the rotation information detection means, and the pickup means for the disc. A method for controlling the rotation of a disk in a recorded information reproducing apparatus, which comprises a traverse means for positioning an arbitrary position in the upper radial direction, wherein a target rotation cycle of the motor means at a target address point in accessing a target address. The step of calculating T1 and the output T2 of the cycle detecting means A step of supplying maximum angular acceleration to the motor means in an open loop until the cycle T1 is reached, and a control signal to the motor means when the output T2 of the cycle detection means reaches the target rotation cycle T1. Shutting off, and controlling the rotation of the motor means when stopping the movement of the traverse means, speed control means,
A method of controlling rotation of a disk, comprising the step of switching to a control loop composed of pickup means and rotation information detection means.