JP2000207822A - Spindle motor controller for optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize stable starting by suppressing a sudden fluctuation of rotational torque applied to an optical disk during the operation of switching from a constant voltage control to a constant linear speed control. SOLUTION: This spindle motor controller is provided with a torque limitation circuit 109 for inputting a first driving signal d1 (third driving signal d3) as the control signal of a linear speed proportional to the error of the linear speed of a rotation control circuit 103 and suppressing the quantity of its fluctuation during the operation of switching from constant voltage control to constant linear speed control, and a switching signal generation circuit 106 for generating a torque switching signal TW based on the increase/decrease of a difference signal between the third driving signal d3 and a specified value d4. During the operation of switching from the constant voltage control to the constant linear speed control, the fifth driving signal d5 of the torque limitation circuit 109 is selected when the torque switching signal TW is ON 'H', and a spindle motor 112 is driven by the control signal of the linear speed, the fluctuation quantity thereof being suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor control device for an optical disk device for recording and reproducing information on and from an optical disk and for starting the disk and controlling the linear velocity constant.

[0002]

2. Description of the Related Art In recent years, optical disk devices have been widely used for recording and reproducing video signals and audio signals.

An example of the configuration of a conventional spindle motor control device for an optical disk device will be described with reference to FIG.

[0004] In FIG.
A light detection circuit that receives laser irradiation light from the optical disk, reads information recorded on the optical disk 101, and detects a tracking error corresponding to a shift amount between a track and a light spot spirally formed on the optical disk 101. The information read detection signal RF is output to the rotation control circuit 103, and the tracking error signal TE is output to the tracking control circuit 113.

The rotation control circuit 103 includes a light detection circuit 102
Input of the information read detection signal RF of the optical disk 10
1. The linear velocity between the optical spot illuminated on the track 1 and the optical disk 101 is detected, an error between the detected linear velocity and a desired linear velocity is calculated, and a first drive signal d1 proportional to the error is generated. Output to the first selection circuit 104.

The first selection circuit 104 includes a rotation control circuit 1
03, a first drive signal d1 and a preset second drive signal d2 (here, a constant value signal) are input, and according to a command signal md of a command circuit 105 described later,
By selecting one of these drive signals d1 and d2, the third
Is output to the drive circuit 111 as the drive signal d3.

[0007] The drive circuit 111 supplies a voltage proportional to the third drive signal d3 to the spindle motor 112 to drive the spindle motor 112.
Numeral 2 drives to rotate the optical disc 101 with a rotation torque corresponding to the voltage.

The tracking control circuit 113 generates a drive signal TRD corresponding to the tracking error signal TE and supplies the drive signal TRD to the tracking actuator 114. The tracking actuator 114 drives the objective lens 115 to move the light spot on the optical disc 101. Follow the track.

The command circuit 105 includes a spindle motor 11
2 outputs a command signal md for switching between constant voltage control and constant linear velocity control.

The starting operation of the spindle motor 112 in the conventional spindle motor control device of the optical disk apparatus thus configured will be described in detail.

First, the command circuit 105 outputs a constant voltage control command to the first selection circuit 104 as a command signal md. Then, the first selection circuit 104 selects the preset second drive signal d2 and outputs the selected second drive signal d3 as the third drive signal d3 according to the constant voltage control command. As a result, a drive signal of a predetermined magnitude is supplied to the drive circuit 111, and as a result, the spindle motor 112 rotates at a constant rotation speed according to the magnitude of the second drive signal d2.

Next, the operation of the tracking control circuit 113 is started to cause the light spot to follow the track on the optical disk 101. Thereafter, as the optical disk 101 rotates, the information detection signal RF is output from the light detection circuit 102.

The rotation control circuit 103 detects a linear velocity between the optical spot and the optical spot irradiating the track on the optical disk 101 based on the input information reading detection signal RF, and detects the detected linear velocity and a desired linear velocity. And outputs a first drive signal d1 to the selection circuit 104 in accordance with the error.

The stable detection signal R from the light detection circuit 102
When F is output, the command circuit 105 switches the command signal md to the linear velocity constant control command, and switches the first selection circuit 104
Output to Then, the first selection circuit 104 responds to the linear velocity constant control command by the first selection circuit 104 of the rotation control circuit 103.
Is selected and output as the third drive signal d3. Thereby, the rotation of the optical disc 101 is controlled so that the linear velocity of the optical disc 101 becomes constant.

An example of the spindle control device of the optical disk device configured as described above is disclosed in JP-A-58-212.
There is one disclosed in Japanese Patent Publication No. 379.

The spindle control device disclosed in Japanese Patent Application Laid-Open No. 58-212379 applies a constant voltage to a control target for a certain period of time at the time of startup, and thereafter determines the state of the reproduction speed by a discriminator and switches to normal speed control. The control is performed smoothly from the stop to the rated rotation.

[0017]

However, in the above configuration, the spindle motor 112 is controlled by a constant voltage control.
Since the rotation speed of the spindle motor when driving the spindle motor is different from the rotation speed of the spindle motor during the constant linear velocity control, after driving the spindle motor 112 with the constant voltage control,
When the control is switched to the constant linear velocity control, the difference in the rotation speed causes a large fluctuation in the third drive signal d3, and the rotation torque applied to the optical disk 101 largely changes. The large fluctuation of the rotation torque on the optical disc 101 has an adverse effect on the tracking control.

Further, depending on the magnitude of the rotation torque fluctuation, a tracking control failure such as a loss of the tracking control occurs, and there is a problem that the optical disc 101 cannot be started.

An object of the present invention is to reduce fluctuations in rotational torque applied to an optical disk when switching from constant voltage control to constant linear velocity control in such a spindle motor control device for an optical disk device.

[0020]

A spindle motor control device for an optical disk device according to the present invention is a control device for controlling a spindle motor for rotating a disk. Light detection means for reading recorded information; rotation control means for detecting a rotation speed of a spindle motor based on a read detection signal of the light detection means and outputting a first drive signal according to an error from a desired rotation speed; Command means for outputting a command signal for switching the drive method of the spindle motor between constant voltage control or constant rotation control and constant linear velocity control; and when the command signal of the command means is a command signal for constant linear velocity control,
The first drive signal of the rotation control means is selected. When the command signal of the command means is a command signal for constant voltage control or constant rotation control, a preset second drive signal is selected, and a third drive signal is selected. First selecting means for outputting as a signal,
A switching signal generating means for generating a torque switching signal when a difference between a third driving signal of the first selecting means and a preset fourth driving signal increases;
A torque limiter for outputting a fifth drive signal in which the amount of change of the drive signal is limited, a torque switch signal of the switch signal generator is continuously generated, and a command signal of the commander is a command for constant linear velocity control. In the case of a signal, the fifth drive signal of the torque limiting means is selected, and when the command signal of the command means is a command signal of constant voltage control or constant rotation control, or the command signal of the command means is a command signal of constant linear velocity control. And when the generation of the torque switching signal by the switching signal generating means is interrupted, a second selecting means for selecting the third drive signal of the first selecting means and outputting it as a sixth drive signal; And a driving means for driving the spindle motor in accordance with the sixth driving signal of the selecting means.

According to the present invention, it is possible to obtain a spindle motor control device for an optical disk device in which fluctuations in rotational torque on the optical disk during switching from constant voltage control to constant linear velocity control are reduced.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a control device for controlling a spindle motor for rotating a disk, which receives laser irradiation light from the disk and records the laser irradiation light on the disk. Light detection means for reading information, rotation control means for detecting a rotation speed of a spindle motor based on a read detection signal of the light detection means, and outputting a first drive signal in accordance with an error from a desired rotation speed; Command means for outputting a command signal for switching the driving method between constant voltage control or constant rotation control and constant linear velocity control; and when the command signal of the command means is a command signal for constant linear velocity control, the first of the rotation control means When the command signal of the command means is a command signal for constant voltage control or constant rotation control, a preset second drive signal is selected, and a third drive signal is selected. First selecting means for outputting as a driving signal, and switching signal generating means for generating a torque switching signal when a difference between a third driving signal of the first selecting means and a preset fourth driving signal increases. A torque limiter for outputting a fifth drive signal in which a change amount of a third drive signal of the first selector is limited; a torque switch signal of a switch signal generator is continuously generated; When the command signal is a command signal for constant linear velocity control, the fifth drive signal of the torque limiting means is selected, and when the command signal of the command means is a command signal for constant voltage control or constant rotation control, or When the command signal is a command signal for constant linear velocity control and the generation of the torque switching signal of the switching signal generating means is interrupted, the third driving signal of the first selecting means is selected and output as the sixth driving signal. The second election to do And means,
A driving means for driving the spindle motor in accordance with the sixth driving signal of the second selecting means, wherein the command signal of the command means changes from a constant voltage control or a constant rotation control to a linear velocity. When the control is switched to the constant control and the second command signal is output, the first drive signal corresponding to the error between the spindle motor rotation speed of the rotation control means and the desired rotation speed is output as the third drive signal. Immediately after that, the difference between the third drive signal and the preset fourth drive signal increases, so that a torque switching signal is generated. Therefore, the fifth drive signal that limits the variation of the third drive signal is generated. The spindle motor is driven in accordance with the fifth drive signal which is output to the drive means as the sixth drive signal and which limits the variation of the third drive signal. This makes it possible to reduce fluctuations in the rotational torque applied to the optical disk when switching from constant voltage control or constant rotation control to constant linear velocity control.

According to a second aspect of the present invention, in the first aspect of the present invention, the switching signal generating means includes a difference signal between a third driving signal and a fourth driving signal of the first selecting means. Absolute value means for generating the absolute value of
A torque switching signal generating means for comparing the output signal of the absolute value means inputted before the timing and generating a torque switching signal when the output signal of the absolute value means increases; When the absolute value of the difference signal between the third drive signal and the fourth drive signal decreases, the torque switching signal is turned off (interrupted), and according to the error between the spindle motor rotation speed of the rotation control means and the desired rotation speed. Third
Is output to the drive unit as a sixth drive signal, and the spindle motor is driven according to the first drive signal of the rotation control unit. Thereby, control performance at the time of constant linear velocity control can be secured.

According to a third aspect of the present invention, in the first aspect of the present invention, the preset fourth drive signal of the switching signal generating means has the same value as the second drive signal. In the switching signal generating means, the third drive signal immediately after the linear velocity constant control is selected becomes equal to comparison with the third drive signal at the time of constant voltage control or constant rotation control, and as a result, A torque switching signal is generated at an accurate timing from the switching signal generating means, and during constant linear velocity control, the switching signal generating means detects a decrease in the difference signal between the third drive signal and the fourth drive signal and switches the torque. The signal is turned off, and therefore, the torque switching signal of the switching signal generating means has an effect of accurately capturing the timing when the constant speed control shifts to the steady state, and turning off the torque switching signal. Thereby, control performance at the time of constant linear velocity control can be secured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same components as those of the conventional example shown in FIG. 7 are denoted by the same reference numerals, and description thereof is omitted.

FIG. 1 is a configuration diagram of a spindle motor control device of an optical disk device according to an embodiment of the present invention.

As described above, the rotation control circuit 103
The detected linear velocity and the desired linear velocity (for example, 1.2 [m / s
ec]), and outputs a first drive signal d1 corresponding to the error. Specifically, when the linear velocity between the light spot and the optical disk 101 is lower than a desired linear velocity,
Since it is necessary to increase the rotation speed of the optical disc 101, the first drive signal d1 has a positive value, and its magnitude is determined by the magnitude of the difference between the linear velocity of the optical spot and the optical disc 101 and the desired linear velocity. Proportional. When the linear velocity between the light spot and the optical disk 101 is higher than a desired linear velocity, the first drive signal d1 has a negative value because the rotation speed of the optical disk 101 needs to be reduced. Is proportional to the difference between the linear velocity between the light spot and the optical disk 101 and the desired linear velocity. In this way, the rotation control circuit 103 generates the first drive signal d corresponding to the difference signal between the linear velocity of the optical spot and the optical disk 101 and the desired linear velocity.
Outputs 1. Here, the operation of detecting the linear velocity between the light spot and the optical disk 101 by the rotation control circuit 103 is performed at predetermined timings (for example, at every 1 [msec]). Therefore, the output of the first control signal d1 of the rotation control circuit 103 is updated and output in synchronization with the operation of detecting the linear velocity between the optical spot and the optical disk 101.

The first selection circuit 105 includes a command circuit 105
, One of the first drive signal d1 and the second drive difference signal d2 (here, a constant value signal) of the rotation control circuit 103 is selected, and the third drive signal is output. Signal d
Output as 3. That is, when the command signal md of the command circuit 105 is a constant voltage control command, the third drive signal d
As 3, the second drive signal d2 is output, and when the linear velocity constant control command is issued, the first drive signal d1 is output as the third drive signal d3.

The third output from the first selection circuit 105
Is input to the torque limiting circuit 109, the second selecting circuit 110, and the switching signal generating circuit 106. [Torque limiting circuit 109] The torque limiting circuit 109 controls the fifth drive signal d in which the variation of the third drive signal d3 is limited.
5 is output. The operation of the torque limiting circuit 109 is shown in FIG.
Is shown in the flowchart of FIG.

The absolute value e (= | d5-d3 |) of the difference between the fifth drive signal d5 output one timing before and the third drive signal d3 input this time is calculated, and the absolute value e of the difference is calculated. Is less than a predetermined value △ d (for example, 1/100 of the maximum variable width of the fifth drive signal d5) (e <△ d), the third drive signal d3 is output as it is as the fifth drive signal d5. (D5 = d3), and the absolute value e of the difference is equal to or greater than a predetermined value △ d,
When the third drive signal d3 is larger than the fifth drive signal d5 one timing before (d5 ≧ d3), a signal obtained by adding △ d to the fifth drive signal d5 one timing before is used as a new fifth drive signal. Output as signal d5 (d5 = d5 + △
d) When the difference is equal to or more than a predetermined value △ d and the third drive signal d3 is smaller than the fifth drive signal d5 one timing before, △ d is subtracted from the fifth drive signal d5 one timing before. The signal is output as a new fifth drive signal d5 (d5 = d5- △ d). Further, the torque limiting circuit 109
In the first operation of the third drive signal d5, since the fifth drive signal d5 output one timing earlier does not exist, the third drive signal d5
3 is output as a fifth drive signal d5 (d5 = d
3).

By the above operation, the third drive signals d3 and 1
If the amount of change (absolute value e) from the fifth drive signal d5 before the timing is less than the predetermined value △ d, the third drive signal d3 is output as the fifth drive signal d5. On the other hand, when the change amount (absolute value e) is equal to or larger than the predetermined value Δd, the third drive signal d3 is not output as the fifth drive signal d5, and the fifth drive signal d5 is output.
Is a signal whose variation is limited to a predetermined value Δd.

FIGS. 3 and 4 show the operation of the torque limiting circuit 109.
Shown in

FIG. 3 is a diagram for explaining the operation when the amount of change of the third drive signal d3 is small. The vertical axis represents the voltage of the drive signal and the horizontal axis represents time. FIG. 3A shows the third drive signal d.
2 and FIG. 2B shows a fifth drive signal d5. As shown in FIG. 3, when the change amount e of the third drive signal d3 is smaller than the predetermined amount Δd, the fifth drive signal d5 becomes the same signal as the third drive signal d3.

FIG. 4 is a diagram for explaining the operation when the amount of change of the third drive signal d3 is large. The vertical axis represents the drive signal voltage, and the horizontal axis represents time. FIG. 4A shows the third drive signal d.
3 and FIG. 4B shows a fifth drive signal d5. As shown in FIG. 4, when the change amount e of the third drive signal d3 is larger than the predetermined amount Δd, the fifth drive signal d5 is a signal in which the change amount of the third drive signal d3 is suppressed. .

As described above, due to the operation of the torque limiting circuit 109, the fifth drive signal d5 becomes a smooth signal even if a large change occurs in the third drive signal d3. [Second selection circuit 110] The second selection circuit 110
Is a torque switching signal T of a switching signal generation circuit 106 described later.
W and the third drive signal d3 of the first selection circuit 104 and the torque limiting circuit 1 according to the command signal md of the command circuit 105.
09, one of the fifth drive signals d5 is selected and output as the sixth drive signal d6. This second selection circuit 11
0 is shown in the flowchart of FIG.

When the command signal md of the command circuit 105 is a constant voltage control command, the torque switching signal TW is continuously output.
The flag F set when the signal becomes H "is set to 1 (F = 1), and the third drive signal d3 is output as the sixth drive signal d6 (d6 = d3).

When the command signal md of the command circuit 105 is a constant linear velocity control command, the operation differs depending on the torque switching signal TW. When it is confirmed from the flag F that the torque switching signal TW is continuously “H”, the sixth drive signal d6
And outputs a fifth drive signal d5 (d6 = d5),
If the torque switching signal TW attains "L" even once (when the flag F = 0), a third drive signal d3 is output as the sixth drive signal d6 (d6 = d3), and thereafter, the command signal m
The third drive signal d3 is output as the sixth drive signal d6 until d becomes a constant voltage control command (d6 = d3).
In the first operation, the flag F is set to 1 (F = 1). [Switching signal generating circuit 106] The switching signal generating circuit 10
In step 6, a third drive signal d3 and a fourth drive signal d4 (here, a constant value signal) are input, and the above-described torque switching signal TW is output. Hereinafter, the configuration and operation of the switching signal generation circuit 106 will be described in detail.

The subtractor 107a of the switching signal generating circuit 106
, The difference between the third drive signal d3 and the fourth drive signal d4 is calculated, and the absolute value circuit 107b calculates the absolute value f of the difference signal between the third drive signal d3 and the fourth drive signal d4.
1 (= | d3-d4 |) is calculated. Absolute value circuit 10
The absolute value signal f1 of 7b is input to the positive side of the input terminals of the delay circuit 108a and the comparison circuit 108b.

The delay circuit 108a outputs a signal delayed by one timing from the input signal. That is, the currently input absolute value signal f1 of the absolute value circuit 107b is stored and output at the next timing. At the first timing, since there is no stored signal, the same signal as the input signal is output. The output signal f2 of the delay circuit 108a is input to the negative input terminal of the comparison circuit 108b. The delay circuit 108a and the comparison circuit 108b constitute a torque switching signal generator (torque switching signal generator) 108.

In the comparison circuit 108b, the output signal f1 of the absolute value circuit 107 input to the positive side of the input terminal and the output signal f2 of the delay circuit 108a input to the negative side of the input terminal
And outputs the result as a torque switching signal TW.

More specifically, when the output signal f2 of the delay circuit 108a inputted to the minus side of the input terminal is larger than the absolute value signal f1 of the absolute value circuit 107 inputted to the plus side of the input terminal (f2> f1). ), "L" as the torque switching signal TW
The signal of is output. When the output signal f2 of the delay circuit 108a input to the minus side of the input terminal is not larger than the absolute value signal f1 of the absolute value circuit 107 input to the plus side of the input terminal (f1 ≧ f2), the torque switching signal As TW "
H ”is output.

F2>f1; TW "L"f1≥f2; TW "H" When the switching signal generating circuit 106 is configured as described above, the fourth
In response to the temporal change of the third drive signal d3 with respect to the drive signal d4 of FIG.
L ”.

That is, when the difference signal between the third drive signal d3 and the fourth drive signal d4 gradually increases, the output signal f2 of the delay circuit 108a input to the minus side of the input terminal is output.
Becomes smaller than the absolute value signal f1 of the absolute value circuit 107 input to the + side of the input terminal of the comparison circuit 108b, and the torque switching signal TW becomes “H”. Further, the third drive signal d
When the difference signal between the third drive signal d4 and the fourth drive signal d4 gradually decreases, the output signal f2 of the delay circuit 108a input to the minus side of the input terminal of the comparison circuit 108b becomes the absolute value of the absolute value input to the plus side of the input terminal. It becomes larger than the absolute value signal f1 of the value circuit 107, and the torque switching signal TW becomes “L”. As described above, the switching signal generating circuit 106 switches the torque switching signal TW to “H” or “L” in accordance with the temporal change of the third drive signal d3 with respect to the fourth drive signal d4.

Next, the start-up operation of the spindle motor driving device of the optical disk device thus configured according to the present embodiment will be described in detail. FIG. 6 shows a flowchart of the operation at the time of starting. In the present embodiment, the second
Is the same value as the fourth drive signal d4 (d4 = d2).

First, the command signal md of the command circuit 105 outputs a constant voltage control command. As a result, in the first selection circuit 104, the second drive signal d2 is changed to the third drive signal d3.
(D3 = d2), and the second selection circuit 110 outputs the third drive signal d3 as the sixth drive signal d6 {d6 = d3 (= d2)}.

From the above, the sixth drive signal d6 has a constant value,
That is, the driving signal has the magnitude of the second driving signal d2. Since the sixth drive signal d6 is a constant value drive signal, the drive circuit 111 supplies a constant value voltage to the spindle motor 112, and thereby the spindle motor 112
Drives the optical disc 101 with a rotational torque corresponding to the magnitude of the sixth drive signal d6, that is, the magnitude of the set second drive signal d2, and the optical disc 101 is rotationally driven.

In the tracking control circuit 113,
A tracking drive signal TRD is output in response to the tracking error signal TE from the light detection circuit 102, and the tracking actuator 114 is driven so that the light spot follows the spiral track on the information recording surface of the optical disc 101.
Drives the objective lens 115. When the light spot accurately follows the track, the light detection circuit 102
Output a stable detection signal RF.

The stable detection signal R from the light detection circuit 102
When F is output, the command circuit 105 outputs the command signal md
Is switched to the linear velocity constant control command, and the first selection circuit 1
04 and the second selection circuit 110.

In the first selection circuit 104, the command signal md
, The first drive signal d1 of the rotation control circuit 103 is output as the third drive signal d3 (d3 = d1). Accordingly, the third drive signal d3 becomes a signal (linear velocity control signal) having a value proportional to the magnitude of the difference between the linear velocity of the optical spot and the optical disk 101 and the desired linear velocity.

The third drive signal d3 is output from the torque limiting circuit 1
09 is input. The torque limiting circuit 109 outputs a signal obtained by limiting the variation of the third drive signal d3 to the second selection circuit 110 as a fifth drive signal d5.

Immediately after the command circuit 105 outputs the linear velocity constant control command as the command signal md, the optical disk 1
Since the rotation speed of the optical disc 101 does not reach the rotation speed of the optical disc 101 such that the linear velocity between the light spot and the optical disc 101 becomes a desired value,
The drive signal d1 has a value significantly different from that of the second drive signal d2.

In the first selection circuit 104, since the first drive signal d1 is selected as the third drive signal d3,
Third drive signal d input to switching signal generation circuit 106
The difference signal between the third drive signal d4 and the fourth drive signal d4 (= d2) increases.

The third signal input to the switching signal generation circuit 106
When the difference signal between the drive signal d3 and the fourth drive signal d4 increases, the torque switching signal TW becomes “H” and is output to the second selection circuit 110.

In the second selection circuit 110, the command signal md
Of the constant linear velocity control command of
When the torque switching signal TW “H” output from the control signal 6 is input, a fifth drive signal d5 is output as the sixth drive signal d6 (d6 = d3). Thereby, the sixth drive signal d
6 is a third drive signal d3 proportional to the difference between the linear velocity of the optical spot and the optical disk 101 and the desired linear velocity.
Are limited.

The sixth drive signal d6 is inputted to the drive circuit 111, and the sixth drive signal d6 is supplied to the spindle motor 112.
Supply a voltage proportional to the magnitude of The spindle motor 112 drives the optical disc 101 to rotate. Thus, the spindle motor 112 is controlled so that the linear velocity between the light spot and the optical disk 101 becomes a desired value.

When the spindle motor 112 is controlled so that the linear velocity between the light spot and the optical disk 101 becomes a desired value, the first drive signal d1 of the rotation control circuit 103 gradually becomes the value of the second drive signal d2. Approach. Here, the second drive signal d2 has the same value as the fourth drive signal d4,
The first selection circuit 104 outputs the third drive signal d3 as the first drive signal d3.
Since the third drive signal d1 is selected, the third drive signal d3 input to the switching signal generation circuit 106 gradually approaches the fourth drive signal d4.

The third signal input to the switching signal generation circuit 106
When the drive signal d3 approaches the fourth drive signal d4, the torque switching signal TW becomes “L” and the second selection circuit 110
Output to

When the torque switching signal TW input to the second selection circuit 110 becomes "L" even once, a third drive signal d3 is thereafter output as a sixth drive signal d6 (d6 = d3). .

The sixth drive signal d6 is input to the drive circuit 111, and the sixth drive signal d6 is supplied to the spindle motor 112.
, That is, a voltage proportional to the first drive signal d1 of the rotation control circuit 103 is supplied. Spindle motor 1
Reference numeral 12 drives the optical disc 101 to rotate.

Thus, the light spot and the optical disk 10
The spindle motor 112 is controlled so that the linear velocity with 1 becomes a desired value, and the activation of the spindle motor control device of the optical disk device is completed.

With the above configuration, even if the control of the spindle motor 112 is switched from the constant voltage control to the constant linear velocity control, a large change in the drive signal to the spindle motor 112 can be eliminated, and the rotation of the optical disk 101 can be prevented. The torque fluctuation can be reduced. Hereinafter, this will be described.

As described above, since the rotation speed of the spindle motor 101 during the constant voltage control does not match the rotation speed of the spindle motor 101 during the steady state of the constant linear velocity control, the command signal md of the command circuit 105 becomes constant voltage. When the control command is switched to the constant linear velocity control command, the value of the third drive signal d3 selected by the first selection circuit 104 greatly changes. However, at this time, the second selection circuit 1
According to 10, the torque limiting circuit 1 is a signal obtained by limiting the variation of the third drive signal d3 as the sixth drive signal d6.
09 is selected as the fifth drive signal d5. Therefore, the sixth drive signal d6 input to the drive circuit 111 is the first drive signal d6.
Of the drive signal d1 is suppressed, and a large change in the drive signal to the spindle motor 112 can be removed.

Further, in this embodiment, the control response in the linear velocity constant control is improved by the operation of the switching signal generating circuit 106. Hereinafter, this will be described.

As described above, switching signal generating circuit 106
Is the same, the fifth drive signal d5 is selected as the sixth drive signal d6 of the second selection circuit 110 (d6 = d5). The fifth drive signal d5 is a drive signal in which the change amount of the first drive signal d1 of the rotation control circuit 103 is suppressed. Therefore, the amount of change in the sixth drive signal d6 at the time of transition from the constant voltage control to the constant linear velocity control can be suppressed, but the control performance of the constant linear velocity control is deteriorated. In other words, while the amount of change is suppressed, after the linear velocity constant control of the optical disk 101 reaches a steady state,
Even if the rotation of the optical disc 101 is disturbed, the disturbance cannot be suppressed. Further, the control band of the linear velocity constant control is considerably restricted.

However, in the present embodiment, the operation of the switching signal generating circuit 106 and the second selecting circuit 110 switches the sixth drive signal d6 during the linear velocity constant control.

Specifically, immediately after switching from the constant voltage control to the constant speed control, the third drive signal d3 is a signal that is significantly different from the fourth drive signal d4. , The third drive signal d3 approaches the fourth drive signal d4. This allows
Torque switching signal TW of torque switching signal generating circuit 108
Becomes “L”. In the second selection circuit 110, when the torque switching signal TW is interrupted, the sixth drive signal d6
Is selected as the third drive signal d3. Therefore, control performance at the time of constant linear velocity control is ensured.

Further, in the present embodiment, the output accuracy of torque switching signal TW of switching signal generating circuit 106 is improved by setting second driving signal d2 and fourth driving signal d4 to the same value (d4 = d2). Has improved. That is, when the change amount of the third drive signal d3 is large, the switching signal generation circuit 1
06 accurately sets the torque switching signal TW to "H",
Select the fifth drive signal d5 as the sixth drive signal d6. Here, the fifth drive signal d5
Is a signal in which the amount of change in the third drive signal d3 is suppressed by the operation of the torque limiting circuit 109. When the change amount of the third drive signal d3 is small, the switching signal generation circuit 1
06 accurately sets the torque switching signal TW to "L",
Select the third drive signal d3 as the sixth drive signal d6 to ensure the control performance at the time of constant linear velocity control. Hereinafter, this will be described.

In the constant voltage control, the first selection circuit 104
By the operation described above, the third drive signal d3 becomes the second drive signal d2
Therefore, the third drive signal d3 is the same as the fourth drive signal d4. Therefore, comparing the amount of change in the third drive signal d3 immediately after the transition to the constant linear velocity control with the fourth drive signal d4 is the same as comparing the third drive signal d3 immediately after the transition to the constant linear velocity control with the constant voltage control. This is equivalent to comparing with the third drive signal d3 (second drive signal d2) at the time. As a result, the switching signal generation circuit 106 can set the torque switching signal TW to "H" at an accurate timing.

On the other hand, during the constant voltage control, the rotation control circuit 1
In order for 03 to detect the linear velocity from the detection signal RF, the rotation speed of the spindle motor 101 needs to be within a predetermined range. Therefore, the value of the second drive signal d2 corresponding to the constant voltage during the constant voltage control is set to a value substantially equal to the value of the third drive signal d3 during the constant linear velocity control.

Therefore, the third drive signal d3 at the time of constant linear velocity control has a value close to the fourth drive signal d4 in a steady state. Further, the spindle motor 1 is controlled during the constant linear velocity control.
Since the rotation speed of 01 gradually approaches the rotation speed in the steady state, the difference signal between the third drive signal d3 and the fourth drive signal d4 of the switching signal generation circuit 106 decreases. The switching signal generating circuit 106 detects the decrease of the difference signal and sets the torque switching signal TW to "L". Therefore, the torque switching signal TW of the switching signal generating circuit 106 accurately captures the timing at which the constant speed control shifts to the steady state, and sets the torque switching signal TW to “L”. Thus, the third drive signal d3 is supplied to the second selection circuit 110 as the sixth drive signal d6.
And the control performance at the time of constant linear velocity control can be secured.

In the present embodiment, the fourth drive signal d4 is set to a constant value. However, the same applies when the command signal uses the third drive signal d3 immediately before outputting the constant linear velocity control command. The effect is obtained.

Further, in the present embodiment, the constant voltage control is performed in the initial stage of the startup, but the same effect can be obtained by performing the constant rotation control.

In the present embodiment, the driving circuit 111
In the above, the configuration is described in which the voltage is supplied. However, a similar effect can be obtained by employing a configuration in which the current or the power is supplied.

Further, the above-described operation can be partially realized by software.

In addition, various changes can be made without changing the gist of the present invention.

[0076]

As described above, according to the present invention, by the operation of the second selecting means and the switching signal generating means, there is no abrupt change in the rotational torque applied to the optical disk, and stable starting can be performed. Effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a spindle motor control device of an optical disc device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of a torque limiting circuit of the spindle motor control device of the optical disc device.

FIG. 3 is a diagram for explaining an operation of a torque limiting circuit of the spindle motor control device of the optical disc device.

FIG. 4 is a diagram for explaining an operation of a torque limiting circuit of the spindle motor control device of the optical disc device.

FIG. 5 is a flowchart illustrating an operation of a second selection circuit of the spindle motor control device of the optical disc device.

FIG. 6 is a flowchart illustrating an operation of the spindle motor control device of the optical disc device at the time of startup.

FIG. 7 is a configuration diagram of a conventional spindle motor control device of an optical disk device.

[Explanation of symbols]

Reference Signs List 101 optical disk 102 light detection circuit 103 rotation control circuit 104 first selection circuit 105 command circuit 106 switching signal generation circuit 107a subtractor 107b absolute value circuit 108a delay circuit 108b comparison circuit 108 torque switching signal generation unit 109 torque limiting circuit 110 second Selection circuit 111 drive circuit 112 spindle motor RF information read detection signal TE tracking error signal TRD tracking drive signal md command signal for switching between constant voltage control and constant linear velocity control TW torque switching signal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D109 EA01 EA11 KA04 KA11 KB03 KB05 KB25 KB32 KD11 KD46 KD47 5H001 AA02 AA08 AB12 AD02 5H560 AA04 AA05 DA01 TT01 TT02 TT06 TT08 XA12

Claims (3)

[Claims] 1. A control device for controlling a spindle motor for rotating a disk, comprising: a light detection unit that receives laser irradiation light from the disk and reads information recorded on the disk; A rotation control means for detecting the rotation speed of the spindle motor based on the read detection signal, and outputting a first drive signal in accordance with an error from a desired rotation speed; Command means for outputting a command signal for switching to constant rotation control and constant linear velocity control; and when the command signal of the command means is a command signal for constant linear velocity control, selecting a first drive signal of the rotation control means; When the command signal of the command means is a command signal for constant voltage control or constant rotation control, a preset second drive signal is selected and a third drive signal is selected. A switching signal generating means for generating a torque switching signal when a difference between a third driving signal of the first selecting means and a preset fourth driving signal increases. A torque limiter for outputting a fifth drive signal in which a change amount of a third drive signal of the first selector is limited; a torque switch signal of the switch signal generator is continuously generated; When the command signal of the command means is a command signal of constant linear velocity control, the fifth drive signal of the torque limiting means is selected, and when the command signal of the command means is a command signal of constant voltage control or constant rotation control, Alternatively, when the command signal of the command means is a command signal of constant linear velocity control and the generation of the torque switching signal of the switching signal generation means is interrupted, the third drive signal of the first selection means is selected, and the sixth drive signal is selected. Drive signal and A spindle motor control device for an optical disc device, comprising: a second selecting unit for outputting the data by a drive unit; and a driving unit for driving the spindle motor in accordance with a sixth drive signal of the second selecting unit. . 2. An absolute value means for generating an absolute value of a difference signal between a third drive signal and a fourth drive signal of the first selecting means, and an output of the absolute value means. A torque switching signal generating means for comparing a signal with an output signal of the absolute value means inputted one timing before and generating a torque switching signal when the output signal of the absolute value means increases. A spindle motor control device for an optical disk device according to claim 1. 3. The spindle motor control device according to claim 1, wherein the preset fourth drive signal of the switching signal generating means has the same value as the second drive signal.