JP2000014180A - Optical disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk unit which allows an optical disk to be smoothly loaded and unloaded. SOLUTION: A motor drive control circuit 7 comprises a power amplifier portion 2 which drives a motor 1, a motor current detecting portion 3 which detects driving currents passed through the motor 1, an AD converting portion 4 which converts analog signals from the motor current detecting portion 3 into digital signals, a motor driving voltage control portion 5 which outputs optimum driving voltages to the motor 1 according to digital signals from the AD converting portion 4, and a DA converting portion 6 which converts digital signals from the motor driving voltage control portion 5 into analog signals. Thereby a motor driving voltage is increased with increase in motor 1 driving current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly, to an optical disk device having an improved motor drive control circuit for a drive motor when loading / unloading an optical disk.

[0002]

2. Description of the Related Art FIG. 11 is a perspective view schematically showing the structure of a conventional optical disc apparatus 200, and FIG. 12 is a front view of a driving force transmitting mechanism of the motor 1 shown in FIG. FIG. 13 is a plan view partially showing gears, and FIG. 14 is a block diagram of the motor drive control circuit 70 shown in FIG.

Referring to FIGS. 11, 12, 13 and 14, a conventional optical disk device 200 is
And a spindle motor (not shown) for rotating the spindle 32 at high speed.
An optical head (not shown) for writing and reading information to and from the optical disk 21, a base plate 33 on which the spindle 32 and the optical head are mounted, and an optical disk 2
A tray 22 having a circular recess 23 larger than the diameter of an optical disk 21 serving as a guide when setting the tray 1 and moving in the horizontal direction, a worm 11 and a belt wheel 24 attached to the upper end of the rotating shaft of the motor 1 , A first spur gear 42 provided with the same rotation axis as the belt wheel 24, a second spur gear 40 meshing with the first spur gear 42, and a second spur gear 40 A fourth spur gear 44 that meshes with a third spur gear 41 having the same rotation axis as the fifth spur gear 4 provided on the same rotation axis as the fourth spur gear 44.
3 and the sixth spur gear 26 meshing with the fifth spur gear 43
And a seventh spur gear 27 that meshes with the sixth spur gear 26, and a rack 28 attached to the side surface of the tray 22.
The teeth 28a of the rack and the seventh spur gear 27 are engaged with each other (the tray 22 is attached in the direction of the arrow), and the rotational force of the motor 1 is transmitted from the seventh spur gear 27 to the tray 22.
A mechanism for horizontally moving the tray 22 in the front-rear direction with respect to the spindle 32, a planetary gear 29 fixing the third spur gear 41 at an eccentric position different from the center axis, and a housing 39 below the base plate 33. When the seventh spur gear 27 is locked, the rotational force of the motor 1 is transmitted to the planetary gear 29 to rotate the planetary gear 29 and mesh with the planetary gear 29 when the seventh spur gear 27 is locked. The rack 30 is moved in the left-right direction, comes into contact with the base plate end surface 33a along the inclined surface 31a of the trapezoidal lifter 31 attached to the rack 30, slides up and down the base plate end surface 33a, and lifter 31 Slope 3
The rear end of the base plate 33 opposite to the side that slides along the base plate end surface 33a along 1a is fixed to the housing 39 via the plate spring 34, and the base plate 33 to which the plate spring 34 is attached is fixed. A motor drive control circuit 70 which comprises a mechanism for raising and lowering the base plate 33 with the fixed point at the rear end as a fulcrum, and a power amplifier section 102 for driving the motor 1 for controlling the motor 1 at a constant drive voltage of 5V. It is composed of

[0004] Next, the operation of the conventional optical disk device 200 configured as described above will be described.

When loading the optical disk 21 into the optical disk apparatus, when the motor 1 rotates, the tray 22 moves horizontally in the direction of the arrow, and the stopper 3 provided at the rear of the housing 39 is provided.
7 moves to a position where the tray 7 comes into contact with the tray 22. When the tray 22 cannot move any more due to the stopper 37, the rotational force of the motor 1 remains unchanged and the seventh spur gear 2
The rotation of 7 is stopped and locked, and the sixth spur gear 26, the fifth spur gear 43, and the fourth spur gear 44 are also locked.

Here, the third spur gear 41 meshing with the fourth spur gear 44 is fixed at an eccentric position different from the center axis of the planetary gear 29 on the planetary gear 29.
Acts to rotate the third spur gear 41 along the circumferential direction of the locked fourth spur gear 44,
With the rotation of the third spur gear 41, the planetary gear 29 rotates to move the rack 30 meshing with the planetary gear 29 to the right as shown in FIG. When the ascent of the base plate 33 is completed, a mechanical sensor (not shown) that senses the completion of the elevation of the base plate 33 operates, and the drive of the motor 1 is turned off.

At this time, the guide posts 35 arranged on the base plate 33 are inserted into the guide holes 36 of the tray 22, and the relative positional relationship between the spindle 32 on the base plate 33 and the optical disk 21 on the tray 22 is within a predetermined range. The optical disk 21 is set and the spindle 3
2 and the loading operation is completed.

On the other hand, when the optical disk 21 is unloaded, when the motor 1 rotates, the guide posts 35 arranged on the base plate 33 are inserted into the guide holes 36 of the tray 22, so that the guide posts 35 The spur gear 27 is locked until it escapes from the hole 36, the planetary gear 29 rotates, the base plate 33 starts to descend, the guide post 35 is released from the guide hole 36, and the base plate 33 completes the descending operation. When the tray 22 moves horizontally in the direction opposite to the arrow, the unloading operation of the optical disk 21 is completed.

Next, load fluctuation of the motor 1 during the loading / unloading operation of the optical disk 21 will be described with reference to the drawings.

FIGS. 10A and 10B are diagrams showing load fluctuations when the optical disk 21 is loaded and unloaded, respectively.

Referring to FIG. 10A, the optical disk 2
When the tray 1 is loaded, the load of the motor 1 has a peak at the time of startup and when the base plate 33 rises, and when the tray 22 moves horizontally, the load is small and the load fluctuation is small. Sometimes the maximum static friction force acts on the motor 1 to increase the load, and then the tray 2
This is because, when the base plate 33 rises, the load increases because the weight of the base plate 33 acts in addition to the tray 22 when the base plate 33 rises. The base plate 33 has a spindle 32,
A spindle motor, an optical head 38 and the like are mounted, and the weight reaches about 300 g.

Referring to FIG. 10B, the optical disk 2
When the motor 1 is unloaded, a maximum load occurs when the motor 1 is started and when the base plate 33 descends continuously,
Thereafter, when the tray 22 moves horizontally, the load is small and the load fluctuation is small.

The motor drive control circuit 70 for controlling the motor 1 controls the drive voltage at a constant voltage of 5 V. As is clear from the relationship between the rotation speed and the rotation torque of the motor 1 shown in FIG. Since the number of rotations of the motor 1 operates in inverse proportion to the magnitude of the load torque, there is a disadvantage that the operation speed in each of the above-described phases when loading and unloading is greatly different.

The mechanism for moving the tray 22 and the mechanism for moving the base plate 33 up and down each have mechanical components that slide frictionally, but these components have different friction coefficients due to variations between the components. In addition, when the mechanical characteristics including the friction coefficient change with the lapse of the use operation time and the load becomes equal to or more than the maximum rotation torque of the motor 1 shown in FIG.
It also has the disadvantage that loading and unloading operations become impossible.

To solve this problem, if the drive voltage of the motor 1 is uniformly set to a large value, the speed of the horizontal movement of the tray 22 becomes too high, and the optical disk 2 on the tray 22
1 cannot be stationary, the optical disc 21 comes off from the circular recess 23 on the tray 22 and the spindle 3
2 or the tray 22 comes into contact with the surface of the optical disk 21, causing a problem such as simultaneous damage such as damage to the optical disk 21.

As another method for solving the problem, there is a method of changing the reduction ratio of a reduction gear for reducing the speed of the motor 1 according to the load of the motor 1, but the mechanical structure becomes very complicated. There are difficulties in downsizing and assembling the device.

[0017]

As described above,
In a conventional optical disk device, a motor drive control circuit that controls a motor that drives a mechanism that moves a tray and a mechanism that raises and lowers a base plate controls the drive voltage at a constant voltage. There is a problem that the operation speed in each phase when unloading greatly differs, and smooth loading / unloading cannot be performed.

An object of the present invention is to provide a motor drive control circuit that changes the motor drive voltage so that the motor drive voltage increases as the motor current increases. An object of the present invention is to provide an optical disk device that realizes an appropriate tray moving speed during horizontal movement.

[0019]

According to the present invention, there is provided an optical disk drive comprising: a spindle for mounting an optical disk and rotating at a high speed;
A spindle motor for rotationally driving the spindle, an optical head for writing / reading information to / from the optical disk, a base plate for mounting the spindle and the optical head, a tray for setting the optical disk and moving in a horizontal direction; A mechanism for moving, a mechanism for raising and lowering the base plate, a motor for driving the movement of the tray and for raising and lowering the base plate, and a motor drive control circuit for controlling the motor. The driving voltage of the motor is changed so as to increase as the driving current value increases.

The motor drive control circuit includes: a power amplifier for driving the motor; a motor current detector for detecting a drive current flowing through the motor; an AD converter for converting an analog signal from the motor current detector to a digital signal; A motor drive voltage control unit that outputs an optimal drive voltage to the motor in accordance with a digital signal from the AD converter, and a DA converter that converts a digital signal from the motor drive voltage controller into an analog signal It is characterized by.

The motor drive voltage control section changes the drive voltage of the motor so that the larger the detected current value is, the higher the detected current value of the motor current detection section is between the specified lower limit value and the specified upper limit value. It is characterized by.

The motor drive voltage control section is characterized by comprising a microcomputer and a memory.

The memory is connected to the microcomputer via the first data bus, and has a conversion table for converting the motor drive voltage controller into a signal for outputting an optimal drive voltage to the motor in accordance with the digital signal from the AD converter. It is characterized by the following.

The microcomputer, the A / D converter and the D / A converter are connected by second and third data buses, respectively. The microcomputer receives a signal from the A / D converter via the second data bus and receives the third data bus. A signal is transmitted to a DA converter via a data bus.

[0025] The motor current detector is characterized in that a resistance smaller than the winding resistance of the motor is connected in series with the motor.

The mechanism for moving the tray includes a worm attached to the upper end of the rotating shaft of the motor, and a belt wheel to which the driving force of the motor is transmitted via the worm and the belt.
A first spur gear provided with the same rotation axis as the belt wheel, a second spur gear meshing with the first spur gear, and a third spur gear having the same rotation axis as the second spur gear And a fourth spur gear meshing with the third spur gear, a fifth spur gear provided on the same rotation axis as the fourth spur gear, and a sixth spur gear meshing with the fifth spur gear. A seventh spur gear meshing with the sixth spur gear is provided, the teeth of the rack attached to the side surface of the tray and the seventh spur gear are fitted and mounted, and the rotational force of the motor is changed to the seventh spur gear. The transmission is performed from the spur gear to the tray, and the tray is translated in the front-rear direction with respect to the spindle.

[0027] The tray is characterized in that it has a circular concave portion larger than the diameter of the optical disk which serves as a guide when setting the optical disk.

The mechanism for raising and lowering the base plate includes a planetary gear fixing the third spur gear at an eccentric position different from the center axis, and a rack movably provided in the left and right direction on a housing below the base plate. When the third spur gear is locked, the rotational force of the motor is transmitted to the planetary gear to rotate the planetary gear, and the rack meshing with the planetary gear is moved in the left and right direction, and is attached to the rack. It is characterized in that the base plate is raised and lowered by sliding in contact with the end surface of the base plate along the inclined surface of the trapezoidal lifter.

In the mechanism for raising and lowering the base plate, an end on the back side of the base plate opposite to the side that slides in contact with the end surface of the base plate along the inclined surface of the lifter is fixed to the housing via a leaf spring. The base plate is raised and lowered by using a fixed point at a rear end of the base plate to which the leaf spring is attached as a fulcrum.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an optical disk drive 1 according to the present invention
One embodiment of 00 will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a motor drive control circuit 7 of the optical disk apparatus 100 of the present invention, and FIG. 2 is a schematic perspective view showing an embodiment of the optical disk apparatus 100 of the present invention.

The optical disk device 100 of the present invention shown in FIG.
Is different from the configuration of the conventional optical disc apparatus 200 only in that the motor drive control circuit 7 of the present invention and the conventional motor drive control circuit 70 are different, and the mechanism configuration is completely the same. The description is omitted here.

The same components as those of the conventional optical disk device 200 are denoted by the same reference numerals.

Referring to FIGS. 1 and 2, the motor drive control circuit 7 includes a power amplifier 2 for driving the motor 1.
And a resistance r smaller than the winding resistance of the motor 1
A motor current detecting unit 3 connected in series with the motor 1 to detect a current flowing through the motor 1, an AD converting unit 4 for converting an analog signal from the motor current detecting unit 3 into a digital signal, and a digital signal from the AD converting unit A motor drive voltage control unit 5 comprising a microcomputer 51 and a memory 52 for outputting an optimal motor drive voltage (digital value) in accordance with this; and a DA converter for converting a digital signal from the motor drive voltage control unit 5 into an analog signal 6 is comprised.

Next, the operation of the optical disk device 100 according to the present invention thus configured will be described.

First, the case where the optical disk 21 is loaded on the spindle 32 will be described.

FIG. 3 is a diagram showing the motor current b during loading.

Referring to FIG. 3, the motor current b has a peak at the time of start-up and at the time of rising of the base plate 33, and the fluctuation becomes small during the horizontal movement. Here, since the motor 1 load is proportional to the motor current b, FIG. 10A showing the motor 1 load at the time of loading and FIG. 3 showing the motor current b at the time of loading have similar shapes. 3
The reason why the shape is slightly different when ascending 3 will be described later.

The motor current b is converted by the motor current detector 3 into a resistance terminal voltage c proportional thereto. However, the motor current detector 3 detects the current without affecting the current flowing through the motor 1. A resistance (0.25 ohm) sufficiently smaller than the winding resistance of the motor 1 is connected in series to the motor 1, and the resistance terminal voltage c is proportional to the motor current b. For example, if the motor current b is 1 A, the resistance terminal voltage c is 250 mV, and the relationship between the motor current b and the resistance terminal voltage c is shown in FIG.

The AD converter 4 converts the resistance terminal voltage c (analog signal) to a digital signal d and outputs the digital signal d via the data bus 9d. The resistance terminal voltage c (analog signal) and the digital signal d Is shown in FIG.

The motor drive voltage control unit 5 generates a digital signal e of an optimal motor drive voltage signal in accordance with the digital signal d.
Is output via the data bus 9e, but the digital signal d
FIG. 6 shows the relationship between the digital signal e. When the digital signal d is 50h or less (the motor current is 1A or less), the digital signal e is constant at 40h. This is motor 1
This is to ensure a constant motor drive voltage in a state where the current is zero immediately before the start, and to prevent the speed irregularity of the tray 22 when the tray 22 moves horizontally. Digital signal d is 50
In the case of h or more (motor current is 1 A or more) and A0h or less (motor current is 2 A or less), as the digital signal d increases, the digital signal e increases. This is to ensure a larger motor drive voltage as the load on the motor 1 increases.

Further, when the signal d is equal to or larger than A0h (the motor current is equal to or larger than 2A), the digital signal e is constant at 80h. This is because when a large motor 1 current flows when the motor 1 is started or when the motor 1 is locked, the motor driving voltage becomes very large, and the motor 1 current further increases in an avalanche type, and the motor 1 is destroyed. This is to prevent the situation.

The motor drive voltage controller 5 comprises a microcomputer 51 and a memory 52. The conversion from the digital signal d to the digital signal e is performed by the memory 52 connected to the microcomputer 51 via the data bus 9m.
Can be realized by having the conversion table shown in FIG.
The display in the conversion table shown in FIG. 7 is displayed in hexadecimal. (For example, the h of 40h in the table is 16
It means that it is in decimal notation. The microcomputer 51 receives the digital signal d from the AD converter 4 via the data bus 9d, converts the digital signal d into a digital signal e having an optimal motor drive voltage by a conversion table on the memory 52, and then sends the data to the DA converter 6 The digital signal e is transmitted via the bus 9e.

The D / A converter 6 converts the digital signal e into an analog signal and outputs an analog signal (signal f). The relationship between the digital signal e and the analog signal f is shown in FIG.
Shown in

The analog signal f is added to a constant voltage of 5 V by the power amplifier section 2 to become a motor drive voltage a.

FIG. 9 shows that the optical disk 21 is
FIG. 5 shows a diagram in which the motor drive voltage a is optimized when loading is performed.

Referring to FIG. 9, when the motor 1 is started, 2A
When the above current flows, the motor drive voltage a is 10 V
During the subsequent horizontal movement of the tray 22, the current of the motor 1 becomes 1A or less, and the motor driving voltage a becomes 5V.
Is clamped to. When the base plate 33 rises, the motor 1 current increases, and the motor drive voltage a also increases. When the motor drive voltage a increases, the number of revolutions of the motor 1 increases, and the back electromotive force generated by the motor 1 itself increases, so that the motor current decreases. Therefore, when the base plate 33 rises, FIG. The shape of FIG. 3 showing the current b will be slightly different.

[0048]

As described above, by providing the motor drive control circuit for changing the motor drive voltage so that the motor drive voltage increases as the motor current increases, the load of the optical disk on the spindle can be reduced when the motor is started. When raising and lowering the base plate, increase the motor drive voltage, increase the rotational torque of the motor to ensure smooth motor startup and the necessary force for raising and lowering the base plate, and reduce the motor drive voltage when moving the tray horizontally, There is an effect that an appropriate tray moving speed can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a motor drive control circuit of an optical disc device according to the present invention.

FIG. 2 is a schematic perspective view showing an embodiment of the optical disk device of the present invention.

FIG. 3 is a diagram showing a motor current at the time of loading an optical disk of the optical disk device of the present invention.

FIG. 4 is a diagram showing a relationship between a motor current and a resistance terminal voltage of the optical disc device of the present invention.

FIG. 5 shows the resistance terminal voltage and AD of the optical disk device of the present invention.
FIG. 6 is a diagram illustrating a relationship with a conversion unit output.

FIG. 6 is a diagram illustrating a relationship between an output of an AD conversion unit and an output of a motor drive voltage control unit of the optical disc device of the present invention.

FIG. 7 is a diagram showing a conversion table in a memory of the optical disc device of the present invention.

FIG. 8 is a diagram showing a relationship between an output of a motor drive voltage control unit and an output of a DA conversion unit of the optical disc device of the present invention.

FIG. 9 is a diagram showing a motor drive voltage when the optical disk of the optical disk device of the present invention is loaded.

FIG. 10A is a diagram illustrating a motor load when an optical disk of a conventional optical disk device is loaded. FIG. 10B is a diagram showing the load of the motor when the optical disk of the conventional optical disk device is unloaded.

FIG. 11 is a schematic perspective view showing a conventional optical disk device.

FIG. 12 is a front view of a driving force transmission mechanism of the motor of FIG. 11;

13 is a plan view of a driving force transmission mechanism of the motor shown in FIG.

FIG. 14 is a block diagram showing a motor drive control circuit of a conventional optical disc device.

FIG. 15 is a diagram showing a relationship between a rotation speed and a rotation torque of a motor.

[Explanation of symbols]

 Reference Signs List 1 motor 11 worm 2, 102 power amplifier section 3 motor current detection section 4 AD conversion section 5 motor drive voltage control section 51 microcomputer 52 memory 6 DA conversion section 7 motor drive control circuit 9d, 9e data bus 9m data bus 21 optical disk 22 Tray 23 Depressed portion 24 Belt wheel 25 Belt 26 Sixth spur gear 27 Seventh spur gear 28 Rack 28a Rack teeth 29 Planetary gear 30 Rack 31 Lifter 31a Inclined surface 32 Spindle 33 Base plate 33a Base plate end surface 34 Plate spring 35 Guide post 36 Guide Hole 37 Stopper 39 Housing 40 Second Spur Gear 41 Third Spur Gear 42 First Spur Gear 43 Fifth Spur Gear 44 Fourth Spur Gear 70 Motor Drive Control Circuit 100 Optical Disk Device 200 Optical Disk Device a motor driving voltage b motor current c resistor terminal voltage d digital signal e digital signal f analog signal r resistance

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[Procedure amendment]

[Submission date] May 7, 1999 (1999.5.7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Wherein said motor drive voltage control unit includes a microcomputer and claim 1 Symbol placement of the optical disk apparatus characterized in that it is composed of a memory.

3. The memory is connected to the microcomputer by a first data bus, and outputs an optimal drive voltage from the motor drive voltage control unit to the motor in accordance with a digital signal from the AD conversion unit. 3. The optical disk device according to claim 2 , further comprising a signal conversion table.

Wherein said microcomputer and said each second the AD converter and the DA converter portion, are connected by a third data bus, the microcomputer, the AD converter via the second data bus 3. The optical disk device according to claim 1, wherein a signal is received from the unit and the signal is transmitted to the DA converter via the third data bus.

Wherein said motor current detection section, the optical disk apparatus according to claim 1, wherein the connecting the winding resistance smaller than the resistance of the motor to the motor in series.

6. A mechanism for moving the tray, a worm mounted on the upper end side of the rotating shaft of the motor, and a belt wheel driving force of the motor is transmitted through the worm and the belt, the belt A first spur gear provided with the same rotation axis as the car, a second spur gear meshing with the first spur gear, and a third spur gear having the same rotation axis as the second spur gear. A fourth spur gear meshing with the third spur gear; a fifth spur gear provided on the same rotation axis as the fourth spur gear; and a sixth spur gear meshing with the fifth spur gear. A spur gear and a seventh spur gear meshing with the sixth spur gear are provided, the teeth of a rack attached to the side surface of the tray and the seventh spur gear are fitted and mounted, and The rotational force of the motor is transmitted from the seventh spur gear to the tray, The optical disk apparatus according to claim 1, wherein the translating back and forth direction relative to the spindle.

7. The tray according to claim 1, wherein the tray has a circular recess that is larger than a diameter of the optical disc and serves as a guide when setting the optical disc.
7. The optical disc device according to 6 .

8. A mechanism for raising, lowering the base plate, said third flat movable on the horizontal direction the housing of the base plate lower planetary gear is fixed to the position which is different eccentric from the center axis of the gear When the seventh spur gear is locked, the rotational force of the motor is transmitted to the planetary gear to rotate the planetary gear, and the rack meshed with the planetary gear is rotated. is moved in the lateral direction, the rack along the inclined surface of the lifter trapezoidal mounted to slide in contact with the base plate end surface of claim 1 or 6, wherein the raising-lowering said base plate Optical disk device.

9. mechanism for raising, lowering the base plate, the end portion of the back side opposite said base plate to the side sliding contact with the base plate end surface along the inclined surface of the lifter through the leaf spring is fixed to the housing, according to claim 1, wherein the raising-lowering the base plate a fixed point of the end of the back side of the base plate, wherein the plate spring is mounted as a fulcrum, to one of 6, 8 An optical disk device as described in the above.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

[0019]

According to the present invention, there is provided an optical disk drive comprising: a spindle for mounting an optical disk and rotating at a high speed;
A spindle motor for rotationally driving the spindle, an optical head for writing / reading information to / from the optical disk, a base plate for mounting the spindle and the optical head, a tray for setting the optical disk and moving in a horizontal direction; a mechanism for moving the, the mechanism for raising-lowering the base plate includes a motor for driving the up and down movement and the base plate of the tray, and a motor drive control circuit for controlling the motor, the motor drive control circuit, motor
Power amplifier that drives the motor
Motor current detector to detect the current
AD converter that converts these analog signals to digital signals
To the motor according to the digital signal from the AD converter.
A motor drive voltage control unit that outputs an appropriate drive voltage;
Digital signal from the motor drive voltage controller to an analog signal
And a D / A converter for conversion.
The controller detects that the current detected by the motor current detector is
Between the upper limit specified value, the drive voltage of the motor is changed so as to increase as the current detection value increases.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Deleted

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Deleted

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G11B 25/04 101 G11B 25/04 101P

Claims (11)

[Claims] 1. A spindle for mounting an optical disk and rotating at a high speed, a spindle motor for rotating the spindle, an optical head for writing and reading information to and from the optical disk, and mounting the spindle and the optical head. A base plate to be placed, a tray for setting and moving the optical disk in the horizontal direction, a mechanism for moving the tray, a mechanism for raising and lowering the base plate, and driving the movement of the tray and the raising and lowering of the base plate And a motor drive control circuit for controlling the motor, wherein the motor drive control circuit changes the drive voltage of the motor to increase as the drive current value of the motor increases. Optical disk device. 2. A motor drive control circuit comprising: a power amplifier unit for driving the motor; a motor current detection unit for detecting a drive current flowing through the motor; and an analog signal from the motor current detection unit converted to a digital signal. AD converter, a motor drive voltage controller that outputs an optimal drive voltage to the motor in accordance with the digital signal from the AD converter, and a digital signal from the motor drive voltage controller that is converted into an analog signal. 2. The optical disk device according to claim 1, comprising a DA converter. 3. The motor drive voltage control unit increases the drive voltage of the motor as the current detection value increases between a lower limit specified value and an upper limit specified value of the motor current detection unit. The optical disk device according to claim 1, wherein the optical disk device is changed as follows. 4. The optical disk device according to claim 2, wherein the motor drive voltage control unit includes a microcomputer and a memory. 5. The memory is connected to the microcomputer by a first data bus, and outputs an optimal drive voltage from the motor drive voltage control unit to the motor according to a digital signal from the AD conversion unit. The optical disk device according to claim 4, further comprising a signal conversion table. 6. The microcomputer, the A / D converter and the D / A converter are respectively connected by second and third data buses, and the microcomputer performs the A / D conversion via the second data bus. 5. The optical disk device according to claim 2, wherein the optical disk device receives a signal from a unit and sends the signal to the DA converter via the third data bus. 7. The optical disk device according to claim 2, wherein the motor current detection unit connects a resistance smaller than a winding resistance of the motor in series with the motor. 8. A mechanism for moving the tray, comprising: a worm attached to an upper end of a rotating shaft of the motor; a belt wheel to which a driving force of the motor is transmitted via the worm and a belt; A first spur gear provided with the same rotation axis as the car, a second spur gear meshing with the first spur gear, and a third spur gear having the same rotation axis as the second spur gear. A fourth spur gear meshing with the third spur gear; a fifth spur gear provided on the same rotation axis as the fourth spur gear; and a sixth spur gear meshing with the fifth spur gear. A spur gear and a seventh spur gear meshing with the sixth spur gear are provided, the teeth of a rack attached to the side surface of the tray and the seventh spur gear are fitted and mounted, and Transmitting the rotational force of the motor from the seventh spur gear to the tray; 2. The optical disk device according to claim 1, wherein the optical disk drive is moved in parallel with the spindle in the front-rear direction. 9. The optical disk device according to claim 1, wherein the tray has a circular recess that is larger than a diameter of the optical disk and serves as a guide when setting the optical disk. 10. A mechanism for raising and lowering the base plate, the planetary gear fixing the third spur gear at an eccentric position different from the center axis, and a mechanism movable left and right on a housing below the base plate. When the seventh spur gear is locked, the rotational force of the motor is transmitted to the planetary gear to rotate the planetary gear, and the rack meshed with the planetary gear is rotated. 9. The base plate according to claim 1, wherein the base plate is moved in the left-right direction, and slides in contact with the end surface of the base plate along the inclined surface of the trapezoidal lifter attached to the rack to raise and lower the base plate. Optical disk device. 11. A mechanism for raising and lowering the base plate, wherein the end on the back side of the base plate opposite to the side that slides in contact with the end surface of the base plate along the inclined surface of the lifter via a leaf spring. The base plate is raised and lowered with a fixing point at an end on the back side of the base plate fixed to a housing and having the leaf spring attached thereto as a fulcrum. An optical disk device as described in the above.