JP2000251358A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical disk device capable of reducing the effect of the tilt with respect to the write-in and read-out of the optical disk and also eliminating the occurence of reduction of access time. SOLUTION: This optical disk device is constituted so that the optical disk 1 placed on a turntable 3 rotating by a motor is irradiated with the light from a pickup part to read or write the information for the optical disk, and a clamp part 100 is provided, which is a tilt adjusting mechanism for making the surface of the optical disk 1 vertical to the optical axis of the light projected from the pickup part by deflecting the optical disk 1 placed on the turntable 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus capable of reading information from an optical disk or writing information to the optical disk.

[0002]

2. Description of the Related Art Currently, information storage devices using optical disks include CDs (Compact Discs) and DVDs (D
digital video disc). Such an optical disk device that reads or writes information from a CD or DVD is provided with a configuration called a pickup. For example, when reading information written on a CD or DVD with an optical disk device, the optical disk is irradiated with laser light from the pickup, and the information written at the position of the optical disk irradiated with the laser light is detected by the reflected light. I do. The detected signal is
The information is converted by a predetermined element and reproduced as, for example, music or video information.

In the optical disk device configured as described above, in order to accurately reproduce information, the irradiation position of the laser beam irradiated by the pickup on the optical disk is controlled with high accuracy, and the laser beam can be accurately irradiated to a predetermined position on the optical disk. Is required. For this purpose, it is desirable that the laser beam is irradiated such that the optical axis of the laser beam is always perpendicular to the surface of the optical disk.

[0004] By the way, the substrate of an optical disk is made of a resin, and there are a lot of substrates having irregularities (hereinafter referred to as undulations) on a horizontal surface on the surface thereof, and those having a deformed surface (hereinafter referred to as bend). When information is read out from an optical disk made of such a substrate by a pickup, a phenomenon occurs in which the angle of the optical disk surface with respect to the optical axis of the laser light changes (hereinafter, referred to as tilt). When tilt occurs, the laser beam
The focus cannot be accurately focused on the optical disk,
An aberration called a top aberration occurs.

[0005] The top aberration affects the irradiation position of the laser beam on the optical disk. Therefore, if this value exceeds the allowable value, the optical disk device may not be able to reproduce or write data on the optical disk. In addition, the influence of such a top aberration on an optical disc becomes more serious in DVDs having a higher recording density than in CDs.

In order to reduce the top aberration, the following optical disk devices have been proposed. FIG. 8 shows an optical disc fixed (clamped) to reduce the tilt of the optical disc.
1 shows an example of an optical disk device that has been used. The illustrated optical disc apparatus includes a turntable 300 on which the optical disc 1 is placed, a spindle 20 for rotating the turntable 300, a clamper 400 that sandwiches the optical disc 1 together with the turntable 300, and a support member 80 that supports the clamper 400. are doing. Also, spindle 2
0 is provided with a clamp magnet 120 for fixing the clamper 400 to the spindle 20, and the support member 80 is provided with a rotary bearing 90 for coupling to the clamper 400.

Further, as disclosed in Japanese Patent Application Laid-Open No. 8-167272, a disk stabilizer for pressing a relatively wide area of an optical disk from above to a turntable is provided to reduce the tilt of the optical disk. is there.

[0008]

However, the optical disk device shown in FIG. 8 applies a constant force to the optical disk 1 in an annular shape having a width a. For this reason, an unnatural force is applied to the optical disk, and the optical disk may bend instead.

The invention described in Japanese Patent Application Laid-Open No. 8-167272 can apply a force to a wider area of an optical disk than the optical disk device shown in FIG. For this reason, it is relatively effective in reducing the tilt of an optical disk that is concavely bent toward the disk stabilizer. However,
This effect is reduced for an optical disk that sags convexly toward the disk stabilizer. Therefore, the present invention
It is difficult to obtain a remarkable tilt suppression effect for a disc whose bending direction cannot be specified, such as a bonded disc such as a DVD or a double-sided disc.

Further, in the invention described in Japanese Patent Application Laid-Open No. 8-167272, the disk stabilizer is made of rubber or plastic. Such materials are
It is known that it is difficult to increase processing accuracy. From such a point, it cannot be said that the invention described in Japanese Patent Application Laid-Open No. 8-167272 still has room for improvement.

In addition to the above-described configuration, a configuration in which the pickup is mechanically driven by following the undulation of the optical disk has been considered. However, such a mechanism makes the pickup itself complicated and heavy. For this reason, the drive of the pickup is limited, and there is a problem that the access time to the optical disc is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide an optical disk apparatus which reduces the influence of tilt on writing and reading of an optical disk and which does not reduce access time. And

[0013]

The above objects can be attained by the following means. That is, the invention according to claim 1 is an optical disc device in which an optical disc is placed on a turntable rotated by a motor, light is emitted from a pickup unit to the optical disc, and information is read or written. A tilt adjusting mechanism for bending an optical disc placed on a turntable to make a surface of the optical disc perpendicular to an optical axis of light emitted from the pickup unit is provided.

With such a configuration, the optical disk bends so that its surface is perpendicular to the optical axis of the light emitted from the pickup unit.

Further, the invention according to claim 2 is characterized in that the tilt adjusting mechanism has a pressing mechanism for bending the optical disk by pressing it.

With this configuration, the optical disk is deflected by being pressed so that its surface is perpendicular to the optical axis of the light emitted from the pickup unit.

According to a third aspect of the present invention, there is provided a tilt sensor for detecting a tilt of the optical disk placed on the turntable, and a pressing mechanism for pressing the optical disk in accordance with the tilt detected by the tilt sensor. And a pressing force control means for controlling pressure.

With this configuration, the optical disk is deflected by being pressed so that its surface is perpendicular to the optical axis of the light emitted from the pickup unit, and the pressing force of the optical disk is reduced. It can be adjusted according to the tilt amount.

Further, the invention according to claim 4 is characterized in that the pressing mechanism presses the optical disk by a force generated electromagnetically.

With such a configuration, the configuration of the pressing mechanism can be made relatively simple.

According to a fifth aspect of the present invention, in the pressing mechanism, the pressing portion for pressing the optical disk is divided into a plurality of portions, and the pressing mechanism presses the optical disk with a different pressing force for each of the divided pressing portions. It is characterized by being able to.

With this configuration, it is possible to press each part of the optical disc with different forces.

According to a sixth aspect of the present invention, the pressing mechanism comprises:
The optical disk is divided in the radial direction of the optical disk.

With this configuration, the optical disk can be pressed with different forces in the radial direction.

According to a seventh aspect of the present invention, the pressing mechanism comprises:
The optical disk is divided in the circumferential direction of the optical disk.

With this configuration, the optical disc can be pressed with different forces in the circumferential direction.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 and 2 of the present invention will be described below. (Embodiment 1) In Embodiment 1, an optical disc is placed on a turntable rotated by a motor, and the optical disc is irradiated with light from a pickup unit to read or write information. A tilt adjusting mechanism is provided for bending the optical disk placed on the table to make the optical disk surface perpendicular to the optical axis of the light emitted from the pickup unit.

Further, a tilt sensor for detecting a tilt of the optical disk is provided, and a pressing force control means for controlling a pressing force of the optical disk fixing portion pressing the optical disk in accordance with the tilt detected by the tilt sensor. It was made.

FIG. 1 is a perspective view for explaining the optical disk device of the first embodiment. The illustrated configuration is roughly divided into a rotating unit 200 that rotates the optical disc 1 and a clamp unit 100 that clamps the rotating optical disc 1 to suppress tilt. In the first embodiment, of such a configuration, the clamp unit 100 corresponds to a tilt adjustment mechanism.

The rotating section 200 has a turntable 3 on which the optical disc 1 is placed, a spindle motor 15 for rotating the turntable 3, and a spindle 2 provided on the spindle motor 15. An annular clamping magnet 12 is provided on the upper surface of the spindle 2. For such a rotating unit 200, the optical disc 1
Is set on the turntable 3 so that the spindle 2 projects from the center hole h.

On the other hand, the clamp unit 100
Adjustment member 5 which is a member for adjusting the tilt of the camera
And a clamper 4 which engages with the tilt adjusting member 5 and clamps the optical disc 1 between the spindle 2 and the spindle 2.
It has two annular magnets 11 a and 11 b having different diameters provided thereon and a support disk 8 that supports the clamper 4.

The clamper 4 has a disk portion 40 and a disk portion 40.
, And a clamp shaft 41 protruding up and down of the disk portion 40 through the center point. A plurality of holes are provided in the disk portion 40. Of these holes, a plurality of holes centered on the circumference of a circle 4a, which is a virtually drawn circle, are defined as holes a and 4b.
A plurality of holes having a center on the circumference of the circle are defined as holes b. The circles 4a and 4b are concentric circles having the same center point as the disk 40 and different diameters, and the circle 4a has a smaller diameter than the circle 4b.

The tilt adjusting member 5 includes a first adjusting member 50a divided in the radial direction of the optical disk, and a second adjusting member 50.
b. Among them, the first adjusting member 50a is
A plurality of first protrusions 5a are provided on the ring 51a, and the second adjusting member 50b is provided on the ring 51b.
A plurality of projections 5b are provided. Such a tilt adjusting member 5 is provided on the first protrusion 5 of the first adjusting member 50a.
a into the hole a of the clamper 4 and the second adjusting member 5
The second protrusion 5b of Ob is inserted into the hole b of the clamper 4 to engage with the clamper 4.

In the tilt adjusting member 5 engaged with the clamper 4, the first protrusion 5a projects from the hole a, and the second protrusion 5a projects from the hole b.
The protrusion 5b comes to project. This first protrusion 5a
A magnet 11a is placed on the upper surface of the second projection 5b.
The magnet 11b is placed on the upper surface of the. As described above,
A mechanism is configured to press the optical disc whose pressing portion is divided into a plurality of pieces in the radial direction of the optical disc.

Further, the support disk 8 has a plurality of projections which are ferromagnetic projections projecting toward the lower surface. A coil is wound around each of the projections, and the projections can be turned into electromagnets by energizing the coils. For this reason, these protrusions are referred to as electromagnet protrusions 6a and 6b, the coil wound around the electromagnet protrusion 6a is referred to as a coil 7a, and the coil wound around the electromagnet protrusion 6b is referred to as a coil 7b (FIG. 2). ). Such electromagnet projections 6a, 6b are provided with holes a,
It is arranged on the circumference of two concentric circles having different diameters corresponding to the holes b (not shown). Of these, the electromagnet projections 6a arranged on the circumference of the circle having a shorter diameter are the magnets 11
The electromagnet protrusions 6b arranged on the circumference of a circle having a longer diameter are arranged on the magnet 11b.

As described above, the clamp unit 100 is assembled. The assembled clamp unit 100 is fixed to the rotating unit 200 with the optical disc 1 interposed therebetween, and clamps the optical disc 1. Note that this fixing is performed by the magnetic force of the clamp shaft 41 of the clamper 4 made of a ferromagnetic material such as iron by the clamp magnet 12.

FIG. 2 shows the clamp section 100 described with reference to FIG.
FIG. 4 is a cross-sectional view illustrating a portion of the rotating unit 200 that engages with the clamp unit 100. It should be noted that the cross section shown in FIG.
0 is a vertical cross section of the rotary unit 200 cut by a straight line passing through the center axis 41 of the clamper 4 and the centers of the holes a and b.

As shown in FIG. 2, the tip of the spindle 2 has a so-called forward tapered shape in which the cross section thereof increases in a uniform ratio downward. For this reason, the optical disc 1 stops at a position where the play between the diameter of the hole h and the diameter of the spindle 2 is minimized, and is positioned both in the radial direction and the height direction. In addition, the turntable 3 is supported by a spring (not shown) from below, and slightly moves up and down. Therefore, the optical disk 1 which is moved up and down in accordance with the position of the optical disk 1 and positioned can be stably mounted.

A support hole 22 is provided at the tip of the spindle 2.
The support hole 22 has a so-called inverted tapered shape in which the upper surface is a circular hole having a circular upper surface, and the cross section of the hole decreases downward at a uniform rate. In the support hole 22, a part (a downwardly protruding part) 41 b of the clamp shaft 41 of the clamper 4 that protrudes downward is inserted. The lower protruding portion 41b has an inverted tapered shape as a whole, and the clamper 4 stops when the diameter of the inverted tapered portion matches the diameter of the support hole 22. In this way, the clamper 4 is fixed to the spindle 2 by the magnetic force of the clamping magnet 12 after being positioned in the radial direction and the height direction.

On the other hand, a portion (upper protruding portion) 41 a of the clamp shaft 41 of the clamper 4 that protrudes upward is engaged with the bearing 9 provided on the support disk 8. The clamper 4 rotates together with the spindle 2. On the other hand, the supporting disk 8 does not rotate because it is fixed to the disk loading mechanism (not shown) of the optical disk device. Therefore, the support disk 8 can support the clamper 4 and stabilize the rotation.

As described with reference to FIG. 1, the first protrusion 5a and the second protrusion 5b are engaged with the clamper 4.
The magnet 11a is placed above the first protrusion 5a, and the magnet 11b is placed above the second protrusion 5b. Further, the electromagnet projections 6a and 6b of the support disk 8 are arranged to face the magnets 11a and 11b.

The magnets 11a and 11b have polarities in the vertical direction in FIG. The electromagnet projection 6
a, the magnet 11a, the magnet 11
coil 7 so that a magnetic force which always repels the polarity of b is generated.
a, a current is passed through the coil 7b. Further, the magnetic force generated in the electromagnet projections 6a and 6b can be adjusted by the magnitude of the current flowing through the coils 7a and 7b. Thus, in the first embodiment, the optical disc can be pressed with different pressing forces for each of the divided first adjustment member 50a and second adjustment member 50b.

The above-described clamp unit 100 operates as follows. FIG. 3 is a diagram showing a state of the optical disc 1 which is clamped. FIG. 3A shows a case where the optical disc 1 is bent so as to be convex upward.
(B) is a figure which shows the case where it is bent so that it may become convex downward. 3A and 3B, the ideal surface of the optical disk 1 (ideal surface) is indicated by a dashed line, and the state of the optical disk 1 clamped without tilt adjustment is indicated by a broken line. The state of the optical disc 1 on which tilt adjustment has been performed is indicated by a solid line. In addition,
3, the shape of the optical disc 1 and the operation of the clamp unit 100 are exaggerated for easy understanding.

1. Adjusting the tilt of the optical disk that is convex upward (FIG. 3A) Among the electromagnet projections 6a and 6b, the electromagnet projection 6 closer to the center of the optical disc 1 (inside).
A current flows through the coil 7a wound around a. This current generates a magnetic field in the coil 7a, and the electromagnet protrusion 6
Then, a magnetic force repelling the magnet 11a is generated at a. The first protrusion 5a is pressed by the generated magnetic force, and presses an area near the center of the optical disc 1. Due to this pressing, the optical disc 1 bends with the point supported by the turntable 3 as a fulcrum. This deflection occurs in a direction in which a portion of the optical disk 1 outside the turntable rises above the ideal surface.

Almost at the same time when the current flows through the electromagnet projection 6a, the coil 7b wound around the electromagnet projection 6b
A current is also passed through. This current generates a magnetic field in the coil 7b, and generates a magnetic force for repelling the electromagnet projection 6b and the magnet 11b. Due to this magnetic force, the second protrusion 5b
Is pressed to press an area of the optical disc 1 outside the turntable 3. Due to this pressing, the bending caused by the pressing of the first protrusion 5a is suppressed, and the surface of the optical disc 1 approaches the ideal surface.

2. Tilt adjustment of an optical disk that is convex downward (FIG. 3B) When the optical disk 1 is convex downward, current flows through the coil 7b wound around the electromagnet projection 6b farther (outside) from the center of the optical disk 1. It is. This current generates a magnetic field in the coil 7b, and the magnet 1
A magnetic force repelling 1b is generated. The second protrusion 5b is pressed by the generated magnetic force, and presses an area outside the turntable 3 of the optical disc 1. Due to this pressing, the optical disc 1 bends with the point supported by the turntable 3 as a fulcrum. This bending occurs in a direction in which a portion of the optical disc 1 outside the turntable 3 falls below the ideal surface.

Almost at the same time when current is applied to the electromagnet projection 6b, the coil 7a wound around the electromagnet projection 6a
A current is also passed through. This current generates a magnetic field in the coil 7a, and generates a magnetic force for repelling the electromagnet projection 6a and the magnet 11a. Due to this magnetic force, the first protrusion 5a
Is pressed to press an area in the turntable 3 of the optical disc 1. By this pressing, the bending generated by the pressing of the second protrusion 5b is suppressed, and the surface of the optical disc 1 becomes closer to the ideal surface.

According to the first embodiment, the optical disk 1 can be pressed between the inside and the outside of the turntable by having such a structure. Therefore, the area where the optical disc 1 is pressed is widened, and the bending caused by the pressing is reduced. For this reason, the ideal surface is approached over a wide area of the optical disc 1, and the tilt of the optical disc can be reduced.

In the first embodiment, the tilt adjusting member 5 is divided into a first adjusting member 50a and a second adjusting member 50b. For this reason, currents of different values are supplied to the coils 7a and 7b, and the optical disc 1 can be pressed with different forces for each part. Therefore, it is possible to press another portion with an optimal force for suppressing the deflection generated by pressing a certain portion. Therefore,
The entire surface of the optical disk 1 can be made closer to the ideal surface, and the tilt of the optical disk 1 can be reduced over the entire surface.

FIG. 4 is a diagram showing the result of verifying the effect of the first embodiment described above. In the figure, state A shows the optical disk 1 set in the conventional optical disk device shown in FIG. 8, and state B shows the optical disk 1 clamped by the optical disk device of the first embodiment. FIG.
The solid line in the drawing is a line indicating the optical disk 1, and the point o in the figure is the center of the optical disk 1 and the point s in the figure is the outer periphery of the optical disk 1. The dashed line is a line parallel to the ideal surface, and the broken line is a tangent to the surface of the optical disc 1. ΘA is the angle between the tangent to the surface of the optical disk 1 in state A and a line parallel to the ideal surface, and θB is the angle between the tangent to the surface of the optical disk 1 in state B and a line parallel to the ideal surface. is there. Both θA and θB indicate that the closer to 0, the closer the optical disk 1 is to the ideal surface.

The circles shown on the lower side in the figure conceptually show the shapes of spots formed on the optical disk 1 in the state A and the state B by the laser beam emitted from the pickup unit. is there. The circles indicate the spot diameter of the laser beam directly. The smaller the diameter is, the closer to the ideal irradiation state, and the larger the diameter, the greater the top aberration of the optical disc 1. The positions marked with circles correspond to the positions of the optical disc 1 in the states A and B drawn on the upper side in the figure.

In state A showing the optical disk 1 of the conventional optical disk apparatus, the spot diameter is minimum at the position of the center o, but becomes larger toward the outer side, and the spot diameter of the outer circumference s is smaller than the top aberration of the optical disk 1. Becomes larger than the allowable range. If the top aberration exceeds the allowable range, a problem occurs in reading and writing of the optical disk 1, and the optical disk device cannot function normally.

On the other hand, the state B which is the state of the optical disk 1 clamped by the optical disk apparatus of the first embodiment
Here, although the spot diameter becomes larger at the center o than at the state A, the spot diameters at all the portions from the center o to the outer circumference s indicate that the top aberration of the optical disc 1 is within the allowable range. Therefore, it is clear that the optical disk device of the first embodiment can function normally in all areas of the optical disk 1.

In the first embodiment, a tilt sensor (FIG. 5) for detecting the tilt of the optical disk 1 is provided.
The tilt sensor is provided in a pickup for writing or reading information on or from the optical disc 1, and moves together with the pickup. For this reason,
The tilt of the position of the optical disk 1 irradiated with the laser beam can always be detected.

As such a tilt sensor, for example, it is conceivable to use a sensor called a pickup integrated type. The pickup-integrated sensor is a sensor that detects the tilt of the optical disk by using a read signal, and is advantageous in detecting the tilt of the optical disk 1 directly above the pickup unit in that it is lightweight and highly accurate. Configuration.

Next, a configuration for controlling the pressing force according to the tilt of the optical disk will be described. FIG. 5 is a block diagram for explaining such a configuration, which is common to a second embodiment described later. The illustrated configuration includes a tilt sensor 30, a control unit 10 that controls a power supply according to a detection result of the tilt sensor 30, and a power supply 20 that supplies a current to the coils 7 a and 7 b according to an instruction from the control unit 10. ing.

In the first embodiment, the above-described pickup-integrated sensor is used as the tilt sensor 30.
The control unit 10 has a memory 14 and a CPU 13. The memory 14 stores data of a tilt amount and a current value to be supplied to the coils 7a and 7b to cancel the tilt. The CPU 13
Is for calculating a current value using the data stored in the memory 14.

The above configuration operates as follows. The controller 10 inputs a signal for quantifying (tilt amount) and detecting a tilt from the tilt sensor 30, and the CPU 13 compares the signal with the memory 14 to obtain a current value corresponding to the tilt amount. Then, the power supply 2 is supplied so that the current having the determined value is supplied.
Control 0. As a result, the obtained current is
a, which is supplied to the coil 7b and generates a magnetic force enough to cancel the tilt on the electromagnet projections 6a, 6b. By repeating such operations at regular time intervals,
During the reading and writing operations, the tilt of the optical disc 1 can be canceled.

Therefore, in the configuration of the first embodiment, each portion of the optical disk 1 can be pressed with a force corresponding to the tilt amount. Therefore, it is possible to press another portion with an optimum pressing force in order to suppress deflection generated by pressing a certain portion. Therefore, the optical disc 1 can be made closer to the ideal surface with higher accuracy, and the tilt of the optical disc 1 can be further reduced.

In the first embodiment, since the tilt adjusting member 5 is divided in the radial direction of the optical disk 1 (the first adjusting member 50a and the second adjusting member 50b), the deflection in the radial direction is particularly reduced. This is effective in adjusting the tilt of an optical disk having undulation.

Further, in the first embodiment, although the sensor portion of the tilt sensor is provided in the pickup, since the configuration is relatively small and light, the pickup can be driven in the same manner as the conventional one, and the access time of the optical disk is reduced. Can be avoided.

Next, the process of pressing the optical disk according to the tilt amount according to the first embodiment will be described with reference to a flowchart. FIG. 6 is a flowchart of a process of pressing the optical disc according to the tilt amount. In the flowchart of FIG. 6, as soon as the process starts, the tilt sensor 30 starts detecting the tilt. Then, it is determined whether the tilt sensor 30 has detected a tilt (S1). As a result of this determination,
When the tilt is detected (S1: Yes), the amount of the tilt is determined (S2).

Subsequently, the current supplied to the coil 6a necessary to cancel the tilt amount (coil current (1)) (S
3) The supply current (coil current (2)) to the coil 6b is calculated (S4). Then, the power supply 20 is supplied so that the calculated current is supplied to the coils 6a and 6b, respectively.
Is controlled (S5). When the above processing is completed, the detection result of the tilt sensor is determined again, and the tilt adjustment processing is repeated.

The present invention relates to the first embodiment described above.
It is not limited to. For example, in the first embodiment,
Although the tilt adjusting member 5 is divided into the first adjusting member 50a and the second adjusting member 50b, the tilt adjusting member 5 may be divided into any number of adjusting members. Further, the arrangement of the electromagnet projections 6a, 6b and the holes a, b of the clamper 4 corresponding thereto is not limited to the example of FIG. 1, but may be arbitrarily arranged.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described. In the second embodiment, the tilt adjustment member is further divided in the circumferential direction of the optical disc in the circumferential direction of the optical disc, and the optical disc can be pressed with different pressing force for each of the divided portions.

FIG. 7 is a perspective view for explaining the optical disk device according to the second embodiment. In FIG. 7, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be partially omitted. The optical disc device according to the second embodiment also includes a rotating unit 200 for rotating the optical disc 1,
It is roughly classified into a clamp section 101 which clamps the rotating optical disc 1 to suppress tilt. In the second embodiment, the clamp unit 101 corresponds to the tilt adjusting mechanism according to the second embodiment.

The clamp unit 101 includes a tilt adjusting member 25 for adjusting the tilt of the optical disc 1,
A clamper 4 that engages with the tilt adjustment member 25 and clamps the optical disc 1 between the spindle 2 and the clamp 2; two annular magnets 21a and 21b having different diameters provided on the clamper 4; And a plate 8.

The tilt adjusting member 25 according to the second embodiment has a first adjusting member 50a and a second adjusting member 50b, and the first adjusting member 50a and the second adjusting member 50b are
It is divided not only in the radial direction of the optical disk but also in the circumferential direction. Further, the magnets 21a and 21b are
The optical disk is divided into a circumferential direction and a radial direction corresponding to the adjusting member 50a and the second adjusting member 50b, respectively.

The first adjusting member 250a is composed of a plurality of plate members 251a curved so as to draw an arc, and first projections 25a provided one by one on the plate members 251a. The second adjustment member 250b includes a plurality of plate members 251b arranged outside the center of the plate member 251a, and second protrusions 25b provided one by one on the plate member 251b. Such a tilt adjusting member 25 is provided in the first
The protrusion 25a is inserted into the hole a of the clamper 4, and the second
Insert the projection 25b into the hole b of the clamper 4
Is engaged.

The magnet 21a and the magnet 2 of the second embodiment
1b is composed of a plurality of plate-shaped magnets curved so as to draw an arc, and this shape corresponds to the plate member 251a and the plate member 251b, respectively. The magnet 21a is placed on the upper surface of the first protrusion 25a, and the magnet 21b is placed on the upper surface of the second protrusion 25b. Further, the tilt adjusting member 2
The clamper 4 engaged with the optical disk 5 engages with the bearing portion of the support disk 8 at a portion protruding above the clamp shaft 41, and the optical disk having a plurality of pressing portions divided radially and circumferentially of the optical disk. A pressing mechanism is configured.

Further, the electromagnet projections 6 a and 6 b provided on the support disk 8 are respectively connected to the magnets 21 via the clamper 4.
a, the magnet 21b is disposed to face the magnet 21b.
Under the magnet 21b, a first protrusion 25a, a second protrusion 25b
There is. Therefore, the coils 7a and 7b are generated such that a magnetic force repelling the polarity of the magnets 21a and 21b is generated.
Current, and the electromagnet projection 6a, the electromagnet projection 6b and the magnets 21a and 21b are repelled so that the optical disc can be pressed for each of the plurality of first projections 25a and second projections 25b.

Also in the second embodiment, the generated magnetic force can be adjusted by the magnitude of the current flowing through the coils 7a and 7b. Therefore, Embodiment 2
Can press the optical disc with different pressing forces for each of the plurality of first protrusions 25a and second protrusions 25b. Further, also in the second embodiment, a tilt sensor can be provided in the pickup to control the pressing force according to the tilt of the optical disk. In such a configuration, the second embodiment is
The pressing force of the optical disk can be adjusted not only in the radial direction but also in the circumferential direction of the optical disk, and the tilt of the optical disk can be reduced with higher accuracy.

The present invention relates to the second embodiment.
It is not limited to. For example, in Embodiment 2,
Although the tilt adjusting member 25 is divided not only in the radial direction of the optical disc but also in the circumferential direction, it may be divided only in the circumferential direction of the optical disc if necessary.

In the second embodiment, the first projection 25
a, the second protrusion 25b is a plate member 251a, the plate member 25
The tilt adjusting member 25 is divided so as to be provided one for each 1b, and each pressing force is independently controlled. But,
The present invention is not limited to such an example, and the plate member 251a and the plate member 251b have the first protrusion 25a and the second protrusion 251a.
The tilt adjusting member 25 may be divided such that any number of the protrusions 25b are provided.

[0075]

The present invention described above has the following effects. That is, according to the first aspect of the present invention,
It bends so that its plane is perpendicular to the optical axis of the light emitted from the pickup unit. Therefore, the tilt of the optical disk is reduced, and it is possible to prevent the reading and writing of the optical disk from being affected by the tilt. Therefore, the first aspect of the present invention can provide an optical disk apparatus capable of reducing the influence of tilt on writing and reading of the optical disk.

According to a second aspect of the present invention, the optical disk is deflected by pressing the optical disk so that its surface is perpendicular to the optical axis of the light emitted from the pickup unit. Since such a configuration does not change the configuration of the pickup unit,
While reducing the effects of reading and writing due to tilt,
Access time can be prevented from being reduced. Therefore, the invention according to claim 2 can provide an optical disk apparatus that reduces the influence of tilt on writing and reading of the optical disk and does not reduce the access time. Further, according to the second aspect of the invention, the structure of the pickup unit is not changed, and the mechanism other than the tilt adjustment may be the same as the conventional one. Therefore, writing and reading can be performed stably.

According to the third aspect of the invention, the pressing force for bending the optical disk can be adjusted according to the tilt amount of the optical disk. Therefore, the pressing force for pressing the optical disk can be optimized, and the tilt can be reduced with higher accuracy.

According to the fourth aspect of the present invention, the pressing mechanism can be adjusted even during the rotation of the optical disk, and the tilt of the optical disk can be controlled in real time.

According to a fifth aspect of the present invention, the pressing mechanism comprises:
Each part of the optical disc is pressed with a different force. Therefore, the optical disk can be made closer to the ideal surface, and the effect of preventing the tilt from affecting reading and writing of the optical disk can be further improved.

The invention according to claim 6 is capable of pressing the optical disk with different forces in the radial direction, and is particularly effective in reducing the influence on the reading and writing of the optical disk having the radial deflection. Can be.

According to the seventh aspect of the present invention, the optical disc can be pressed with different forces in the circumferential direction, and it is particularly effective in reducing the influence on the reading and writing of the optical disc having the flexure in the circumferential direction. Can be emitted.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an optical disc device according to a first embodiment.

FIG. 2 is a cross-sectional view showing a clamp portion described with reference to FIG. 1 and a portion of the rotating portion that engages with the clamp portion.

3A and 3B are diagrams illustrating a state of the optical disk clamped by the optical disk device according to the first embodiment, wherein FIG. 3A illustrates an optical disk in which the optical disk 1 is bent so as to be convex upward;
(B) is a figure which shows the optical disk which bent so that it might become convex downward.

FIG. 4 is a diagram showing the result of verifying the effect of the first embodiment.

FIG. 5 is a block diagram for explaining a configuration in which the tilt sensor according to the first embodiment controls a pressing force according to the tilt of the optical disc.

FIG. 6 is a flowchart of a process of pressing an optical disc according to a tilt amount performed in the first embodiment.

FIG. 7 is a perspective view illustrating an optical disc device according to a second embodiment;

FIG. 8 shows an example of an optical disk device configured to clamp an optical disk in order to reduce tilt of the optical disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle 3 Turntable 4 Clamp 5, 25 Tilt adjusting member 6a, 6b Electromagnetic projection part 7a, 7b Coil 10 Control part 11a, 11b, 21a, 21b Magnet 12 Clamp magnet 13 CPU 14 Memory 20 Power supply 30 Tilt sensor 50a , 250a First adjusting member 50b, 250b Second adjusting member 51a, 51b Ring 100, 101 Clamping section 200 Rotating section 251a, 251b Plate member

Claims (7)

[Claims] 1. An optical disk device for mounting an optical disk on a turntable rotated by a motor, irradiating the optical disk with light from a pickup unit, and reading or writing information, wherein the optical disk device is mounted on the turntable. An optical disc device, comprising: a tilt adjustment mechanism that bends the selected optical disc to make a surface of the optical disc perpendicular to an optical axis of light emitted from the pickup unit. 2. The optical disk device according to claim 1, wherein the tilt adjusting mechanism has a pressing mechanism for bending the optical disk by pressing the optical disk. 3. A tilt sensor for detecting a tilt of the optical disk placed on the turntable, and a pressing force control means for controlling a pressing force of the pressing mechanism for pressing the optical disk in accordance with the tilt detected by the tilt sensor. 3. The optical disk device according to claim 2, further comprising: 4. The optical disk device according to claim 2, wherein the pressing mechanism presses the optical disk by a force generated electromagnetically. 5. The pressing mechanism according to claim 2, wherein a pressing portion for pressing the optical disk is divided into a plurality of portions, and the pressing mechanism can press the optical disk with a different pressing force for each of the divided pressing portions. 5. The optical disk device according to any one of items 1-4. 6. The optical disk device according to claim 5, wherein the pressing mechanism is divided in a radial direction of the optical disk. 7. The optical disk device according to claim 5, wherein the pressing mechanism is divided in a circumferential direction of the optical disk.