JPH0750068A - Drive controller for clv type disc - Google Patents

Abstract

PURPOSE:To attain a target r.p.m. of a spindle motor quickly without causing increase of maximum current or lowering of efficiency through the use of conventional motor characteristics by employing a steady drive power supply and a higher voltage power supply as the drive power supply for the spindle motor. CONSTITUTION:Voltages of 10V and -10V are power supply voltages for driving a spindle motor 14 steadily whereas the voltages 12V, -12V are power supply voltages for driving the spindle motor at a rate of 1.2 times that of the steady r.p.m. The plus and minus voltages are employed, respectively, for acceleration and deceleration of the spindle motor. Switches SW1, SW2 switch the driving voltage of the spindle motor, respectively, between + or -10V and + or -12V. A transistor Q1 performs conduction on the accelerating side as shown by an arrow FA whereas a transistor Q2 perform conduction on the decelerating side as shown by an arrow FB.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a CD, a CD-ROM,
CLV (Constant Linear Vel) such as MD and MD-ROM
The present invention relates to a drive control device for an ocity (constant linear velocity) type disk, and more specifically to an improvement of a drive control device for a CLV type disk suitable for high-speed access such as double speed or quadruple speed.

[0002]

2. Description of the Related Art An example of a recording / reproducing apparatus for a CLV type disk is shown in FIG. In FIG. 1, a transducer (indicated by TD) 1 such as an optical pickup or a magnetic head (not shown) is provided for the disk 10.
2, the information is recorded and reproduced along the spiral track. This disk 10 is CLV (constant linear velocity)
Spindle motor driven in rotation (displayed in SPM) 14
The rotation control of is performed by the spindle motor driver 16.

RF output from the transducer 12
The signal is amplified by the RF amplifier 18 and supplied to the signal processing / servo control unit 20. Signal processing / servo control unit 20
Is a microprocessor unit (displayed in MPU) 22
Are connected to obtain a reproduction signal of information recorded on the disk 10, a focus error signal for the transducer 12, a tracking error signal, and a rotary servo control signal for the spindle motor 14.

The reproduced signals are CD, CD-ROM, MD,
MD-ROM signal processing circuits 24, 26, 28, 30
Will be supplied to the required one. In addition, for example, CD
The signal processing circuit 24 includes an error correction circuit, a digital filter, a D / A converter, etc., and reproduces an audio signal. The CD-ROM signal processing circuit 26 and the MD-ROM signal processing circuit 30 include an error correction circuit, a buffer memory, a SCSI interface, etc., and data are reproduced by these.

The MD signal processing circuit 28 includes an EMF demodulation circuit, an error correction circuit, an ATRAC decoder and the like, by which an audio signal is reproduced.
Furthermore, when recording information on the disc 10,
A processing circuit for recording is also included in each.

The control signal is sent to the signal processing / servo control unit 20.
Are supplied to the transducer 12, the spindle motor driver 16, and the transducer driver 21, respectively. The transducer 12 controls focus and tracking, and the spindle motor driver 16 controls CLV of the spindle motor 14.

By the way, C such as CD and MD
Even in the recording / reproducing apparatus for the LV type disc, recently, it is required to speed up the processing operation. Especially CD-ROM and MD-R
For data disks such as OM, transducer 1
There is a demand for speeding up that is comparable to that of HDDs for access of 2 and rotation of the spindle motor 14 and data transfer in the processing circuits 26 and 30.

Regarding the speed-up technology for this CD-ROM drive, etc., see, for example, "World CD-ROM Guide" 1993.
/ There is one disclosed in P84 of Vol.6. The CLV type disc is driven to rotate at a higher speed toward the inner periphery of the disc. For example, 200 rpm at the outer circumference and 52 rpm at the innermost circumference.
It is 0 rpm. Particularly in a data disk such as a CD-ROM, everywhere on the disk is accessed. At that time, in addition to the fact that the transducer has reached the corresponding track, the rotational speed of the disk is a specified linear velocity. It is necessary to be.

The relationship between the rotational speed and the torque of the spindle motor that rotationally drives the disk is as shown in FIG. 7 (A), for example. In the figure, the vertical axis represents the rotation speed (rpm) and the horizontal axis represents the relative torque (%). Graph GA is an example of characteristics at the time of normal driving, and the relative torque is 10 at the maximum when the rotation speed is "0".
It is 0%. The torque decreases as the rotation speed increases,
It rotates at 2000 rpm under no load. 200 mentioned above
In the range WA (1 × speed) of ˜520 rpm, the torque is about 89˜74%.

When the double speed drive is performed on this characteristic, the range WB of the rotational speed becomes 400 to 1040 rpm, and the torque decreases to about 73 to 47%. When such a decrease in torque occurs, it takes a considerable amount of time to obtain the specified disc rotation speed. In particular, when accessing the inner peripheral side of the high rotational speed from the outer peripheral side of the low rotational speed, the influence becomes remarkable.

By the way, there are various factors in order to improve the access speed by the high-speed drive, but the arrival time until the disk reaches the specified rotation speed has a great influence. Therefore, if the Sbindle motor has characteristics such as GB shown in the same figure, the torque performance is improved and the arrival time can be reduced. According to the characteristic of the graph GB, at the double speed indicated by WB, it is possible to obtain the same torque as at the single speed of the characteristic of the graph GA.

[0012]

However, when the spindle motor having the characteristics shown in the graph GB is used, there are the following inconveniences. The motor itself becomes large, and it is not possible to meet the demand for smaller size and lighter weight. In addition, the power consumption will be significantly increased. That is, the fact that the slope of the graph GB is larger than that of the graph GA means that the generated torque per unit current decreases according to the ratio of the slope. As a result, the efficiency is halved and the current increases significantly.

FIG. 2B shows the relative torque (or the number of revolutions) of the spindle motor having the characteristics of graphs GA and GB.
And the relative current (%) are shown in the graph GAI
Corresponds to the graph GA, and the graph GBI corresponds to the graph GB. As is clear from a comparison of these GAI and GBI, if there is no spatial limitation and there is no other loss in the spindle motor having the characteristics of graph GB, the current will be doubled.

Furthermore, as the current increases, the amount of heat generated also increases. As a result, the temperature of the spindle motor itself and the circuit rise, and the disks and transducers located in the vicinity are affected by thermal expansion.

Therefore, as a solution to the above-mentioned inconvenience, a spindle motor having a characteristic as shown by GD in FIG. 9A in which the torque and the number of revolutions are about 1.2 times can be considered. However, even in this spindle motor,
As compared with the motor of graph GA, 1.2 times the current is consumed at the time of startup. Further, the motor itself becomes large in order to obtain the characteristics of the graph GD, resulting in an increase in cost. In particular, when a spindle motor having this characteristic is used in a combined device of 1x speed and 2x speed, the 1x speed device has excessive characteristics and is wasteful.

The present invention focuses on these points,
CLV that can utilize the conventional motor characteristics and can reach the target rotation speed at high speed without increasing the maximum current and lowering the efficiency.
It is an object of the present invention to provide a drive control device for a mold disk.

[0017]

In order to achieve the above object, the present invention provides a CL for driving and controlling a disk, on which information is recorded or reproduced by a transducer, by a CLV.
In a drive controller for a V-shaped disk, first power supply means for steadily driving a spindle motor that rotates the disk, at least one second power supply means having a higher voltage value, and transducers before and after access. Power source switching control means for switching the power source means on the basis of the position information and the number of revolutions of the disc at those positions.

[0018]

According to the present invention, as the power source for driving the spindle motor, at least one first power source means for steady driving and second power source means having a voltage higher than this are prepared. Then, these power supplies are switched according to the movement of the transducer, and a high voltage is applied to the spindle motor during movement. As a result, the torque of the spindle motor increases, and the disk is quickly controlled to the desired number of revolutions of the access destination in a short time.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a drive control device for a CLV type disk according to the present invention will be described in detail below with reference to the accompanying drawings. <First Embodiment> FIG. 1 shows a main portion of a first embodiment of the present invention. In the figure, in a spindle motor driver 50 according to this embodiment, the base and emitter of an NPN transistor Q1 and a PNP transistor Q2 are connected to each other. The output side of the comparator G1 is connected to these bases, and the spindle motor 14 is connected to the emitter. The inverting input side (minus side) of the comparator G1 is supplied with the servo control signal SCON from the signal processing / servo control unit 20 described above,
The comparison reference signal SREF is supplied to the non-inverting input side (plus side).

Next, the changeover switch SW1 is connected to the collector side of the transistor Q1, and two power supply voltages of 10 V and 12 V are supplied to the changeover input side thereof, respectively. A selector switch SW2 is connected to the collector side of the transistor Q2, and its selector input side is
Two power supply voltages of -10V and -12V are supplied respectively.

The voltages 10V and -10V are the voltages when the spindle motor 14 is driven by the graph GA of FIG. 7A, and the voltages 12V and -12V are the ones.
This is a voltage when driven by a double graph GD. Also,
The positive voltage is a power source for accelerating the spindle motor 14, and the negative voltage is a power source for decelerating the spindle motor 14.

Next, the spindle motor 14 is provided with a speed sensor (indicated by VS) 52 such as an FG (frequency generator) for detecting the rotation speed of the spindle motor 14. The detection output side of the spindle motor 14 is power source switching control. It is connected to the section 54. The output side of the power source changeover control unit 54 has a changeover switch S.
It is connected to the switching control side of W1 and SW2.

Of the above parts, the changeover switch SW1,
SW2 is the drive voltage of the spindle motor 14 ± 10
It is for switching between V and ± 12V. Also,
The transistor Q1 is for energizing the acceleration side indicated by the arrow FA, and the transistor Q2 is for energizing the deceleration side indicated by the arrow FB. The degree of energization in the directions of arrows FA and FB by these transistors Q1 and Q2 is a servo indicating a suitable degree of acceleration and deceleration predicted from the applied voltage profile to the spindle motor 14, that is, the relationship between the current position and the accessed position. It is controlled by the control signal SCON.

The power supply switching control unit 54 can be included in the signal processing / servo control unit 20 shown in FIG. 6, and the current position information and target position information of the transducer 12 and the rotation control of the disk 10 at those positions are controlled. Information is given. Then, these information and the speed sensor 52
It is for controlling the changeover of the changeover switches SW1 and SW2 by utilizing the rotation speed information of the spindle motor 14 obtained from the above.

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 2 shows the graphs GA and GD shown in FIG. Operation at Startup Start First, the operation at startup start at double speed will be described with reference to FIG. In the case of 1 × speed, the graph GA operates on the graph GA as described in the related art. As described above, since the power source switching control unit 54 is provided with the transducer position information of the access destination and the disk rotation speed information at those positions, the following control is performed using these information.

In a normal CD player, the TOC recorded on the innermost track of the disc 10 at the start of activation.
Access (Table of Contents). This innermost track is 1040 rpm at double speed. A control signal for controlling the spindle motor 14 to its rotation speed is supplied from the signal processing / servo control unit 20 side to the comparator G1 of the spindle motor driver 50.

As a result, the degree of conduction of the transistors Q1 and Q2 is controlled, and a state in which a current flows at the transistor Q1 side is initially obtained. On the other hand, since it is the start of activation, the speed determination control unit 54 causes the changeover switch SW1
Is switched to the 10V side (SW2 is -10V side).
As a result, the spindle motor 14 is started at 10V at the time of starting even at double speed. That is, FIG.
As shown by the arrow F1 in (A), it is activated along the graph GA. The spindle motor 14 passes through point a1 in the figure and further reaches point a2. The change in speed during this period is detected by the speed sensor 52, and the detected value is monitored by the power supply switching control unit 54.

When the torque generated by the spindle motor 14 is examined, it is 100% at the time of start-up, as indicated by a0 in FIG. However, when the rotation is started, the counter electromotive voltage VE (proportional to the number of rotations) generated from the winding acts, so that the power supply voltage VC apparently decreases by that amount and the generated torque also decreases. That is, the motor terminal voltage V becomes V = VC-VE. Therefore, if the power supply voltage VC is increased when the rotation speed becomes high, a torque equivalent to that at the time of starting can be obtained.

Therefore, in this embodiment, when the rotational speed reaches the point a2 of the graph GA, the speed determination control unit 54 causes the changeover switch SW1 to switch from 10V to 12V (SW2 is -1).
Switch from 0V to -12V). Then,
As indicated by the arrow F2, it moves to the point d1 of the graph GD, and the torque is the same as that at the point a0 (at the time of starting).
It becomes 0%. With this drive voltage of 12 V, it moves to point d2 as shown by arrow F3, and the rotation speed of the innermost track is 10
A rotation speed of 40 rpm is obtained. Then, the TOC recorded on the innermost track is accessed.

In this state, a large torque is not required because it only needs to rotate at a constant speed. Therefore, in order to reduce the power consumption, the changeover switch SW1 is switched to the 10V side (SW2 is -10V side) by the power supply switching control unit 54. This causes d2 as indicated by arrow F4.
The point moves from the point to the point a3, and the spindle motor 14 operates normally. While reading the TOC information, the transducer 12 advances from the inner track to the outer track of the disk 10. For this reason, the rotation speed of the spindle motor 14 decreases, but at this time, no torque is required, so that the motor is continuously driven with the drive voltage of 10 V and moves on the graph GA in the direction of arrow F5.

Operation at Random Access Next, an operation in the case of randomly accessing another position from an appropriate position on the disk will be described with reference to FIG. The most basic operation is to drive the spindle motor 14 on the graph GA, usually with a voltage of 10 V, as shown in FIG. Then, the voltage is set only for the mobile access, and the changeover switch SW1 is set to the 12V side (SW2
Is switched to the −12V side) and driven on the graph GD.
For example, when accessing from the a10 point to the a11 point, the voltage is set to 12 V, the voltage moves from the a10 point to the d10 point, and the speed shifts on the graph GD as shown by an arrow F10. Then, when the speed reaches the target track speed of d11, the arrow F11
As shown by, return to 10V (-10V) and move to point a11.

On the contrary, when the points a11 to a10 are accessed, the spindle motor 14 is similarly driven as indicated by the arrow F12. In this case, the spindle motor 14
Since the operation is to decelerate, the changeover switch SW2 is changed from -10V to -12V (SW1
Is switched from 10V to 12V). The comparator G1 is controlled so that a current mainly flows on the side of the transistor Q2 based on the input control signal. For this reason,
A current flows in the spindle motor 14 in a direction opposite to that during acceleration, and deceleration is performed.

Then, when the target speed is reached, the changeover switch SW2 is changed over from -12V to -10V side (SW1 is from 12V to 10V) this time (see arrow F13). When the target speed is reached, the comparator G1
By controlling the energization of the transistors Q1 and Q2 by the above, a predetermined steady rotation state is achieved. Next, when accessing from the inner side to the outer side of the disk 10, the spindle motor 14
Since the control for decelerating is performed, the torque is not particularly required. Therefore, in this case, as indicated by an arrow F14 in FIG.
You may make it move on A.

As described above, according to the present embodiment, by preparing a plurality of power supply voltages and switching them according to the rotation speed of the spindle motor, it is possible to increase the maximum current without increasing the maximum current. It is possible to reduce the access time during double speed operation and realize quick access. Further, it is possible to sufficiently meet the demands for downsizing, weight reduction, and cost reduction.

<Second and Third Embodiments> Next, referring to FIG.
The second and third embodiments will be described with reference to FIG. A second embodiment is shown in FIG. The second embodiment is also an example in which the spindle motor 14 is a brush motor, as in the first embodiment. As the power supply voltage, only + 10V and + 12V are prepared, and the negative power supply voltage is not prepared. But PN
P-type transistors Q3 and Q4 and NPN-type transistors Q5 and Q6 are turned on and off by switching control signal SF / R.
By doing so, the energization direction can be switched to FA and FB. The switching control signal SF / R is shown in FIG.
Is supplied from the signal processing / servo control unit 20.

The comparator G1 is connected to the base of the transistor Q7 which is connected to the emitters of the transistors Q5 and Q6, and the energization amount is controlled by this. Further, the emitter side of the transistors Q3 and Q4 is connected to the power source voltage 1 via the MOS type FETs Q8 and Q9.
They are connected to the 2V and 10V sides, respectively. FET Q8
The power switching control unit 54 is connected to the gate of
The output side of the power supply switching control unit 54 is directly connected to the gate of the FET Q9.
That is, the FETQ
Either one of 8 and Q9 is turned on and the other is turned off.

The operation of the second embodiment is basically the same as that of the first embodiment, and the acceleration / deceleration of the spindle motor 14 is controlled by the transistors Q3 to Q6. Further, the amount of electricity supplied corresponding to the number of rotations is performed by the comparator G1 and the transistor Q7. Further, the switching control of the power supply voltages 10V and 12V shown in FIGS. 2 and 3 is performed by the power supply switching control unit 54, the inverting circuit G2, and the FETs Q8 and Q9.

FIG. 4B shows the third embodiment. In this embodiment, the spindle motor 14 is a three-phase brushless motor, and the power supply voltage is +
Only 10V and + 12V are available. The output side of the power source changeover control unit 54 is connected to the control side of the changeover switch SW3, and the power source voltages 10V and 12V are supplied to the changeover side of the changeover switch SW3. Then, the voltage switched by the changeover switch SW3 is applied to the spindle motor 14 via the three-phase motor driver 60. The three-phase motor driver 60 controls the energization amount and acceleration / deceleration of each winding of the spindle motor 14.

<Other Embodiments> The present invention is not limited to the above embodiments, and includes, for example, the following ones. (1) In the above-described embodiment, in the case of the 1 × speed, the graph GA is operated in the same manner as in the prior art. However, the graph GD can be used for the 1 × speed as shown in FIGS. 2 and 3. If so, the access time can be shortened.

(2) Further, as shown in FIG. 5A, an intermediate level between the graphs GA and GD, for example, a power supply voltage of 11V is prepared, and in the case of 1 × speed, the moving operation at the time of access on this graph GC. May be performed (arrows F15, F16
reference). Further, as shown in FIG. 7B, the movement operation at the time of access may be performed by using both the graph GD of the voltage 12V and the graph GE of the voltage 11V (arrow F).
17-F18). Furthermore, in order to further increase the access speed, a higher voltage may be prepared and switched in multiple stages.

(3) The above embodiment is for the case of the double speed, but of course the same can be applied to the higher triple speed, quadruple speed, .... (4) In the above-described embodiment, after the access, the graph is returned to the graph GA to reduce the power consumption. However, when the load may increase due to the increase in the rotation speed of the disk, the graph is returned to the GA. Instead, it may be always located on the graph GD in a steady state. Alternatively, the position may normally return to the position above the GA, and the position may be positioned above the GD depending on the degree of the fluctuation only when the rotation fluctuation due to the impact or the like is applied.

(5) In addition, the circuit configuration can be modified in various ways, such as by software configuration using a microcomputer or the like. The present invention is also applicable to a case where a large number of tracks are divided into groups such as MCLV as a disc to be applied, and CLV is driven between the groups and CAV is performed within the group. It is possible.

(6) In the above embodiment, the rotation speed information of the spindle motor, that is, the disk is obtained by the speed sensor. However, the speed information is read from the disk by using the interval of the sectors on the disk or the interval of the synchronization signal. You may get it.

[0044]

As described above, the CL according to the present invention
According to the drive controller for the V-shaped disk, the first power supply means for steady drive and the second power supply means having a higher voltage than that are prepared as the power supply for driving the spindle motor, and the high voltage is used at the time of access. Is applied to the spindle motor, the conventional motor characteristics can be utilized to reach the target rotation speed of the spindle motor at high speed without increasing the maximum current or lowering the efficiency. There is an effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a drive control device for a CLV type disk according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a control operation of the first embodiment.

FIG. 3 is an explanatory diagram showing another control operation example of the first embodiment.

FIG. 4 is a configuration diagram showing a second embodiment and a third embodiment of the present invention.

FIG. 5 is an explanatory diagram showing another operation example of the present invention.

FIG. 6 is a block diagram showing an example of a disc recording / reproducing apparatus.

FIG. 7 is an explanatory diagram showing a driving method of a conventional CLV type disk.

[Explanation of symbols]

10 ... Disk, 12 ... Transducer, 14 ... Spindle motor, 20 ... Signal processing / servo control section, 50 ...
Spindle motor driver, 52 ... Speed sensor, 54 ...
Power supply switching control unit, 60 ... 3-phase motor driver, FA, F
B ... Arrows showing energization direction, F1 to F5, F10 to F20 ... Arrows showing control direction, GA, GC, GD ... Graph showing characteristics of spindle motor, G1 ... Comparator, Q1 to Q7 ... Transistors, Q8, Q9 ... FET, SW1 to SW3 ... Changeover switch, a0 to a3, a10, a11, d1 to d2, d10, d11 ...
Control point.

Claims (1)

[Claims] 1. A CL for driving and controlling by CLV a disk on which information is recorded or reproduced by a transducer.
In a drive controller for a V-shaped disk, first power supply means for steadily driving a spindle motor that rotates the disk, at least one second power supply means having a higher voltage value, and transducers before and after access. 2. A drive control device for a CLV type disk, comprising: a power source switching control means for switching the power source means based on the position information of the above and the rotational speed information of the disk at those positions.