JPH0845175A - Rotation control device for disk information medium - Google Patents

Abstract

PURPOSE:To reduce power consumption in a driving transistor by supplying a voltage to a motor driving means while selecting either one of power supplying means having different voltages. CONSTITUTION:In the case where ON signal is inputted to a power source selecting terminal 27, since a transistor 26 is turned on and a transistor 25 is also turned on, electric power from a power source 22 is supplied and the collector of a motor driving transistor 28 becomes to be at about 12V. Next, in the case where an OFF signal is inputted to the power selecting terminal 27, since the transistor 26 is turned off and the transistor 25 is also turned off, power of about 5V is supplied from a power source 21 to the collector of the motor driving transistor 28. In short, either power sources 21 or 22 supplying electric power to the motor driving transistor 28 is selected by inputting the ON signal or the OFF signal to the power source selecting terminal 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation control device for a disc information medium.

[0002]

2. Description of the Related Art In recent years, a rotation control device for an information recording and reproducing device using a disc information medium has been used in all fields. The field used is C for acoustics.
Examples include D (compact disk), CD-ROM for games and computers, hard disk for computer external recording, floppy disk, optical disk, and the like.

Also, as described in, for example, Japanese Patent Application Laid-Open No. 4-291056, a CD and a CD-ROM are used.
Is a device capable of reproducing data at high speed by rotating the disc at a standard speed when the content recorded on the disc is music data, and at a high speed when the content is a CD-ROM. Proposed. Recent C
For the D-ROM reproducing device, a device for rotating a disk by switching between standard speed and double speed or standard speed and quadruple speed is gradually being used.

An example of a conventional rotation control device of this type will be described below with reference to the drawings. FIG. 4 is a schematic block diagram showing the configuration of a conventional disc information medium rotation control device. In FIG. 4, 1 is a motor drive transistor, 2 is a motor, 3 is a back electromotive force generated inside the motor 2, and 4 is an internal resistance of the motor 2. Now, the power supply voltage is Vd, the voltage applied to the transistor 1 is Vtr, the counter electromotive force coefficient of the motor 2 is Eg, the internal resistance value of the motor 2 is R, the rotational angular velocity is ω, the current flowing through the motor 2 is Is, and the motor 2 Torque constant is Kt, torque is Tl
, And the power consumed by the transistor 1 is Ptr, the following equation holds. Vtr = Vd−ω · Eg−R · Is (1) Ptr = Vtr · Is (2) Tl = Kt · Is (3)

For example, the power supply voltage Vd = 12 [V
], Torque constant Kt = 0.3 [g.cm/mA], counter electromotive force coefficient Eg = 3.1 [mV / rpm], internal resistance R
= 10 [Ω], the torque required to rotate the disk is Tl
= 40 [g · cm], the current required for rotation is Is = 133.3 [mA] from the formula (3). Here, if the rotational angular velocity is ω = 2400 [rpm], then from equation (1), Vtr = 3.23 [V] and equation (2)
Power consumed by the drive transistor 1 from Ptr = 4
It becomes 30 [mW]. This power consumption is not a problem.

Here, ω = 600, which is a quarter of the rotation speed
When it is reduced to [rpm], Vtr = 8.8 from the equation (1).
[V] and Ptr = 1170 [mW] from equation (2)
Becomes As shown in this example, when the number of revolutions is reduced to ¼, the power consumed by the transistor 1 increases by about 2.7 times. All of this power causes a loss such as heat generation, which causes the heat generation of the transistor 1 to reduce the reliability of the device. A heat sink may be attached to the transistor 1 to deal with this heat generation, but attaching the heat sink causes an increase in volume and cost of the device.

Further, Japanese Patent Laid-Open No. 4-064916 discloses that
A recording / reproducing apparatus capable of magnetically or optically recording / reproducing has been proposed using a recording medium having both an optical region and a magnetic recording region. When the head is brought into contact with the magnetic recording area of such a recording medium to read or write data, a head load is applied to the disk, and therefore a large torque is required for rotation. Here, in the above example, ω = 600 [rp
m]. For example, if the torque required for rotation is doubled due to the contact of the head, Tl = 8
It becomes 0 [g · cm]. From the formula (3), the current required for rotation is Is = 266.7 [mA]. From equation (1), Vt
Since r = 7.5 [V], Ptr = 2 from the equation (2).
It becomes 000 [mW]. This power consumption is increased by about 1.7 times as compared with the case where the head is not in contact. In this way, when the head contacts and the head load is applied to the disk, the torque required for rotation increases, and the power consumption further increases.

In a device capable of reproducing a CD or a CD-ROM, the rotation of the disc is CLV (Constant).
Linear Velocity) control, in order to rotate at a constant linear velocity, a large torque is required to change the rotational speed at high speed. However, when the disk is rotating at a constant number of revolutions, such as when waiting for access, the torque is required by the motor because the disk rotates under the force of inertia generated by the rotation of the disk. The size is sufficient to compensate for the friction and the loss due to the air resistance of the media. That is, when the disc is rotated by CLV, a large torque is required, but when the disc is rotated at a constant rotation speed, a small torque is sufficient. Also, since a large torque is required to change the rotation speed at high speed, it is necessary to apply a large voltage to the motor.However, when rotating at a constant rotation speed, a small torque is sufficient. Can be small. This means that when a constant voltage is supplied to the motor drive transistor, the torque required for rotation increases when the rotation speed is changed at high speed, so most of the supply voltage is applied to the motor and power loss in the drive transistor is lost. However, at a constant rotation speed, the torque required for the motor is small, and the voltage applied to the motor is small. Therefore, a large voltage is applied to the drive transistor and power consumption in the drive transistor is increased.

[0009]

As described above, a rotation control device capable of rotating a disc at a high speed, such as a CD-ROM reproducing device capable of rotating the disc at a high speed, is necessary for driving. Since the voltage becomes high, the motor is rotated at a low speed, or in a rotation control device in which a magnetic recording area is provided on the disk and the magnetic head is in contact with or out of contact with the magnetic recording area, the head comes into contact and rotates. When torque is required, or a large amount of torque is required to change the rotation speed at high speed in a device that can reproduce CDs or CD-ROMs, the required torque is small when rotating at a constant rotation speed. When the voltage applied to the motor is small, the power consumption in the motor drive means increases, and all this power becomes a loss such as heat generation, which is caused by the heat generation of the transistor. There is a problem of lowering the reliability of the apparatus Te.

In view of the above problems, it is an object of the present invention to provide a disk information medium rotation control device capable of reducing the power consumption of a drive transistor.

[0011]

In order to achieve the above object, a disk information medium rotation control device of the present invention comprises a motor for rotating the disk information medium, a driving means for driving the motor, and a rotation speed of the motor. A rotation speed control means for outputting a command signal for controlling the driving means to the drive means, and at least two power supply means having different voltages for supplying power to the drive means,
Power selecting means for supplying power to the driving means by selecting one of these power supplying means is provided.

[0012]

According to the present invention, with the above-described structure, when the motor is rotated at a low speed by the rotation control device capable of rotating the disk at a high speed, or when the disk has a magnetic recording area, the magnetic head is located in the magnetic recording area. At least two voltages are required when a large torque is required to rotate the head in contact or non-contact with the rotation control device, or when the rotation control device that changes the rotation speed at high speed rotates at a constant rotation speed. It is possible to reduce the power consumption in the motor drive means by selecting one of the different power supply means and supplying the voltage to the motor drive means.

[0013]

【Example】

(Embodiment 1) Hereinafter, a rotation control device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a rotation control device according to a first embodiment of the present invention. In FIG. 1, 11 is a disc information medium. Reference numeral 12 is a motor for rotating the disk. Thirteen
Is a motor driving means for driving the motor 12. 14
Is a rotation speed control means for controlling the rotation speed of the motor 12. Reference numeral 15 is a power selection means for selecting a power supply source to supply power to the motor drive means, and reference numerals 16 and 17 are two power supply means having different voltages.

FIG. 2 is a schematic diagram showing a circuit configuration of the rotation control device of FIG. In FIG. 2, reference numerals 21 and 22 denote power supplies whose voltages are 5 [V 1] and 12 [V 2] respectively, and correspond to the power supply means 16 and 17 in FIG. Reference numerals 23 and 24 denote reverse current prevention diodes. Reference numerals 25 and 26 are switching transistors, and 27 is a power source selection terminal. Two
Reference numeral 8 is a motor drive transistor, 29 is a drive command terminal for giving a command to the transistor 28, 30 is a motor for rotating the disk information medium 11, 31 is a back electromotive force generated inside the motor 30, Reference numeral 32 is an internal resistance of the motor 30.

The operation of the rotation control device configured as described above will be described below with reference to FIGS. 1 and 2. First, the power selection means 15 of FIG. 1 will be described with reference to FIG. When an ON signal is input to the power supply selection terminal 27, the transistor 26 turns on and the transistor 25
Is also turned on, power is supplied from the power supply 22 and the collector of the motor drive transistor 28 becomes about 12 [V]. Next, when an off signal is input to the power supply selection terminal 27, the transistor 26 is turned off and the transistor 25
Is also turned off, power is now supplied from the power supply 21, and the collector of the motor drive transistor 28 has about 5
[V] is supplied. That is, by inputting an ON signal or an OFF signal to the power supply selection terminal 27, it is possible to select one of the power supplies 21 and 22 that supplies power to the motor drive transistor 28.

Here, an ON signal is input to the power source selection terminal 27 to select the power source 22, and the motor drive transistor 28 is selected.
When 12 [V] is supplied to, for example, the torque constant K
t = 0.3 [g · cm / mA], the back electromotive force coefficient of the motor 30 is Eg = 3.1 [mV / rpm], the internal resistance value of the motor 30 is Ri = 10 [Ω], and the disc information medium 11 Assuming that the torque required for rotation of Tl = 40 [g · cm], the current required for rotation is Is = 13 from the equation (3).
It becomes 3.3 [mA]. Here, the rotational angular velocity is ω = 240
If 0 [rpm], then Vtr = 3.23 from equation (1).
It becomes [V] and the motor drive transistor 2 is calculated from the equation (2).
The power consumed in 8 is Ptr = 430 [mW].
This power consumption is not a problem.

Next, ω = 600, which is a quarter of the rotation speed,
When the speed is reduced to [rpm], a command signal is sent from the rotation speed control means 14 of FIG. 1 to the motor drive means 13 to generate a command voltage at the drive command terminal 29 of FIG. At this time, by inputting an OFF signal to the power source selection terminal 27 of FIG.
[V] is supplied. At this time, Vd of the equation (1) is 5 [V
], Vtr = 1.8 [V], Ptr = 240
It becomes [mW].

Here, even if the number of revolutions is lowered from 2400 [rpm] to 600 [rpm], 5 [V] of the power source 21 is not selected and 12 [V] of the power source 22 is still selected. If set to Vtr = 8.8 from equation (1),
[V] and Ptr = 1170 [mW] from equation (2)
Therefore, this power consumption causes the above-mentioned problem.

As described above, according to the present embodiment, the electric power selecting means 15 selects one of the two electric power supplying means 16 and 17 having different voltages according to the number of revolutions, and the electric power is supplied to the motor driving means 13. By supplying the power, it is possible to reduce the power consumption in the motor drive unit 13.

In this embodiment, the power supply voltage is 5 [V].
However, the same effect can be obtained with other voltage values such as 5 [V] and 8 [V] or 8 [V] and 12 [V]. Is.

(Embodiment 2) Next, a rotation control device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic diagram showing the configuration of the rotation control device in the second embodiment. Only the parts different from the first embodiment will be described. Reference numeral 41 is a disk information medium having an optical recording area on its surface, 42 is a magnetic recording area provided on the surface opposite to the disk information medium 41, and 43 is a magnetic field for reading and writing data from the magnetic recording area 42. The head,
Reference numeral 44 is a head control means for controlling contact / non-contact of the magnetic head 43 with the magnetic recording area 42, and the power selection means 1
Connected to 5. The circuit configuration of the main part is the same as in FIG.

The operation of the rotation control device configured as described above will be described below with reference to FIGS. 3, 1 and 2.

First, when the power source selection terminal 27 inputs an ON signal to select the power source 22 and 12 [V] is supplied to the motor drive transistor 28, for example, the torque constant Kt.
= 0.3 [g.cm/mA], the back electromotive force coefficient of the motor 30 is Eg = 3.1 [mV / rpm], the internal resistance value of the motor 30 is Ri = 10 [Ω], and the rotational angular velocity is ω = 600 [rp
m], first, the magnetic head 43 magnetic recording area 4
When the disk information medium 41 does not come into contact with T2, the torque required for the rotation of the disc information medium 41 is Tl = 20 [g.cm].
It becomes [mA]. In addition, from the equation (1), Vtr = 9.5 [V
], The motor drive transistor 28 can be calculated from the equation (2).
The power consumed in Ptr is 633 [mW]. This power consumption is not a problem.

Next, when the magnetic head 43 is brought into contact with the magnetic recording area 42 by using the head control means 44, a large torque is required because the head load is applied to the disk information medium 41, and Tl = 80 [g. cm]. At this time, the head control unit 44 outputs a signal indicating that the head is in contact with the power selection unit 15, the power selection unit 15 selects the power supply 21, and the motor drive transistor 28.
Is supplied with 5 [V]. From the formula (3), the current required for rotation is Is = 266.7 [mA]. Further, from the formula (1), Vtr = 0.5 [V], and from the formula (2), Ptr = 133 [mW]. This power consumption is of no concern.

Here, even if the magnetic head 43 comes into contact, the power source 22 does not need to select 5 [V] of the power source 21.
When 12 [V] is left selected, Vtr = 7.5 [V] from the equation (1) and Ptr = 2000 [mW] from the equation (2). The voltage applied to the transistor is higher when the head is not in contact than when the head is in contact, but the current is smaller when the head is not in contact, so the power is higher when the head is in contact. In this example, when the magnitude of the torque is quadrupled, the power consumed by the transistor is approximately fifteen times, and the above-mentioned problem occurs.

As described above, according to this embodiment, the electrode supporting arm amount selecting means 1 is selected according to the magnitude of the torque required for rotation.
5 selects one of the two power supply means 16 and 17 having different voltages to supply power to the motor drive means 13, whereby the power consumption of the motor drive means 13 can be reduced. In the present embodiment, the case where the power supply voltage is 5 [V] and 12 [V] has been described, but other voltage values, for example, 5 [V] and 8 [V], 8 [V] and 12 [V]. ], It is obvious that the same effect can be obtained.

(Third Embodiment) Next, a rotation control device according to a third embodiment of the present invention will be described. The configuration of the rotation control device of the third embodiment is similar to that of FIG. However, the rotation control device of this embodiment is a device that can reproduce both a CD and a CD-ROM. The operation of this embodiment will be described below with reference to FIG. The power selection means 15 selects the power supply means 16, 17 only when the rotation speed control means 14 changes the current rotation speed of the motor to a different rotation speed at a high speed, for example, when the rotation speed is controlled by CLV control. By selecting the higher voltage, the motor drive means 13
It is possible to reduce the electric power consumed by.

As described above, according to the present embodiment, only when the rotational speed is changed at a high speed, the power selecting means 15 selects the higher voltage of the power supplying means 16 and 17 to drive the motor. The power consumption can be reduced by supplying the power to the power supply 13.

[0029]

As described above, according to the present invention, the motor for rotating the disk information medium, the driving means for driving the motor, and the rotation speed control means for outputting the command signal for controlling the rotation speed of the motor to the driving means. And at least two power supply means having different voltages for supplying power to the drive means, and power selection means for selecting one of these power supply means and supplying power to the drive means. When rotating the motor at a low speed with a rotation control device that can rotate at a high speed, or when the head has contact with a rotation control device that has a magnetic recording area on the disk and the magnetic head contacts or does not contact the magnetic recording area. Even when a large torque is required for rotation, or when the rotation control device that changes the rotation speed at high speed rotates at a constant rotation speed, the rotation speed or rotation is required. According to the magnitude of the torque or the change in the number of revolutions, one of the two voltage supply means having different voltages is selected to supply the electric power to the motor drive means, so that the power consumption in the motor drive means can be reduced. Have.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a configuration of a rotation control device according to first and third embodiments of the present invention.

FIG. 2 is a schematic circuit diagram showing a circuit configuration in the embodiment.

FIG. 3 is a schematic block diagram showing the configuration of a rotation control device according to a second embodiment of the present invention.

FIG. 4 is a schematic circuit diagram showing a configuration of a conventional motor drive circuit.

[Explanation of symbols]

 11 Disk Information Medium 12 Motor 13 Motor Drive Means 14 Rotation Speed Control Means 15 Power Selection Means 16 Power Supply Means 17 Power Supply Means 21 Power Supply 22 Power Supply 23 Reverse Current Prevention Diode 24 Reverse Current Prevention Diode 25 Switching Transistor 26 Switching Transistor 27 Power source selection terminal 28 Motor drive transistor 29 Motor drive command terminal 30 Motor 31 Motor back electromotive force 32 Motor internal resistance 41 Disk information medium 42 Magnetic recording area 43 Magnetic head

Claims (6)

[Claims] 1. A motor for rotating a disc information medium, a drive means for driving the motor, a rotation speed control means for outputting a command signal for controlling the rotation speed of the motor to the drive means, and the drive means. At least two power supply means having different voltages for supplying power;
A rotation control device for a disk information medium, comprising: one power supply means and power selection means for supplying power to the drive means. 2. The rotation control device for a disc information medium according to claim 1, wherein the disc information medium is a CD (compact disc) or a CD-ROM. 3. The disk information medium rotation control device according to claim 1, wherein the power selection means selects the power supply means in accordance with a change in the rotation speed or the torque or the rotation speed. 4. A disk information medium has an optical recording area on one side and a magnetic recording area on the opposite side or the same side, and is provided with a magnetic head for reading and writing data from the magnetic recording area. The rotation control device for a disk information medium according to claim 1 or 2, wherein. 5. A head control means for controlling contact / non-contact of the magnetic head with the magnetic recording area, wherein the power selecting means includes a power supply means having a low voltage when the magnetic head is in contact with the magnetic recording area. The rotation control device for a disc information medium according to claim 4, wherein the rotation control device is selected. 6. The disk information according to claim 5, wherein the power selection means selects a high voltage power supply means when the rotation speed is changed from the current rotation speed including the start-up of the motor. Medium rotation control device.