JPH11144365A - Disk driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To soften impacts caused by the unnecessary movement of an optical pickup device during the movement of the optical pickup device stopps or power is turned off in a driving device. SOLUTION: In a disk driving device 10, an optical pickup device 15 is moved by a feed motor 30 via an idle gear 33, a follower gear 35 or the like constituting a flat gear transmission mechanize, the power input side of the feed motor 30 is short-circuited during the movement of the optical pickup device 15 stopps or power is turned off to generate an inverse starting force in the feed motor 30, and then the feed motor is braked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device having an optical pickup device for reading information signals from an optical recording medium such as an optical disk.

[0002]

2. Description of the Related Art Hitherto, an optical recording medium such as an optical disk has been proposed, and a disk drive device having an optical pickup device for reading an information signal from such an optical recording medium has been proposed. An optical pickup device of this disk drive device includes a light source such as a semiconductor laser and an objective lens, a grating lens, a beam splitter, and the like for guiding and condensing a light beam emitted from the light source onto a signal recording surface of an optical recording medium. And an optical component. This optical pickup device converges a light beam emitted from the light source on a signal recording surface of an optical recording medium and irradiates the light beam, and uses a photodetector to reflect a reflected light beam of the light beam reflected by the signal recording surface. By detecting, the information signal recorded on the signal recording surface is read.

[0003] An optical disk as an optical recording medium is held in a disk drive device provided with an optical pickup device at a central portion by a disk table constituting a rotation drive mechanism, and is rotated by a spindle motor. In this disk drive device, the optical pickup device is disposed so that the objective lens faces the signal recording surface of the optical disk to be rotated. Further, the optical pickup device is supported so as to be movable over the inner and outer circumferences of the optical disk.

[0004] When the optical disc is rotated, the optical pickup device transmits an information signal recorded along a substantially concentric spirally formed recording track on the signal recording surface of the optical disc. And read out along the recording track.

By the way, when the optical disc is rotated, the recording track is positioned at the center of curvature of the recording track.
Due to the eccentricity with respect to the rotation center of the optical disk (the center axis of the drive shaft of the spindle motor), the optical disk periodically reciprocates in the radial direction of the optical disk at the reading position by the optical pickup device. Further, when the optical disc is rotated, the signal recording surface is periodically cycled in a direction perpendicular to the signal recording surface at a reading position by the optical pickup device due to distortion (flatness error) of the disc substrate of the optical disc. Reciprocally move.

[0006] In order to cope with such eccentricity and so-called surface runout of the optical disc, the optical pickup device is provided with an objective lens driving mechanism (biaxial actuator). The objective lens driving mechanism supports the objective lens so as to be movable in the optical axis direction of the objective lens and in a direction perpendicular to the optical axis (radial direction of the optical disk). This objective lens driving mechanism detects signals (tracking error signal and focus error) that detect the amount of deviation (distance) between the focal point of the light beam by the objective lens and the recording track in the radial direction of the optical disk and in the direction perpendicular to the signal recording surface. The objective lens is moved on the basis of the signal.

As described above, when the objective lens is moved by the objective lens driving mechanism, the focal point of the light beam by the objective lens always follows the periodic movement of the recording track and the recording point is always recorded. It will be formed on the track.

[0008]

In the disk drive device configured as described above, a method of transmitting the power of a feed motor to the optical pickup device via a worm gear and a lead screw is mainly used as a feeding method of the optical pickup device. However, in recent years, in order to increase the speed represented by a CD-ROM and reduce the cost of a portable disk drive device, methods of transmitting power of a feed motor by a spur gear and a pinion rack have been increasing.

By the way, in the case of a disc player or the like, when the disc drive is dropped, a certain impact is applied to the disc drive device, and a design is adopted such that the impact value is not increased to a certain value or more. However, as is well known, a spur gear as a power transmission mechanism has a high transmission efficiency.
When the disc player or the like falls, in the disc drive device, the optical pickup device moves rapidly while rotating the feed motor via the spur gear mechanism. In this case, the optical pickup device is located near the stopper. In the stopped state, the amount of movement is small, but conversely, in the state of stopping away from the stopper, the amount of movement is large, and the optical pickup device slides down and collides with the stopper, and the disk drive The device may be subjected to more shock than it is applied to the device, and the characteristics may be degraded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disk drive device capable of preventing characteristic deterioration of an optical pickup device due to a drop impact of a disk player or the like.

[0011]

In order to achieve the above object, the present invention provides an optical disk for recording and / or reproducing information signals on an optical recording medium which is rotationally driven by a rotational driving mechanism on a chassis. What is claimed is: 1. A disk drive device comprising a pickup device movably disposed on a chassis, a gear mechanism constantly meshed with the optical pickup device, and a feed mechanism for moving the optical pickup device via the gear mechanism. A motor and a short-circuit means for short-circuiting the power input side of the feed motor when the movement of the optical pickup device is stopped; and while the movement of the optical pickup device is stopped, the power input side of the feed motor is turned off. The feed motor is electrically short-circuited so that the feed motor is braked by the reverse starting force generated by the rotation of the rotor. It is characterized in.

Further, in the present invention, the gear mechanism is constituted by a spur gear, and the optical pickup device is connected to a pinion rack.

Further, the present invention is arranged such that the short-circuit means is arranged on the power input side of the feed motor so that the optical pickup device is electrically short-circuited while the movement of the optical pickup device is stopped and in response to a power-off signal. .

In the disk drive device according to the present invention thus configured, when the optical pickup device tries to move suddenly when the operation is stopped or when the power supply is off, the feed motor is short-circuited on the power input side. The optical pickup device is braked by the generation of the reverse starting force and is braked via the gear mechanism, so that the impact is reduced and the characteristic deterioration is prevented.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, a disk drive device according to the present invention uses an optical disk as an optical recording medium and reads information signals from the optical disk, and includes an optical pickup device as an information signal reading mechanism. It is a thing.

First, as shown in FIG.
1 includes a disk-shaped disk substrate made of a transparent material such as polycarbonate (Polycarbonate), and a signal recording layer 102 formed on one main surface of the disk substrate. The disk substrate has a diameter of, for example, about 64 mm, 80 mm, or 120 mm, and has a circular chucking hole (positioning hole) 101a at the center. The signal recording layer 102 includes, for example, fine concave portions (pits) formed on one main surface of the disk substrate and a reflective film (a metal thin film such as aluminum) formed on the one main surface. Have been.

In the optical disk 101, a boundary surface between the disk substrate and the signal recording layer 102 is a signal recording surface. A light beam for signal reading is condensed and irradiated on the signal recording surface through the disk substrate. On this signal recording surface, a spiral recording track having a substantially concentric shape is formed. When the information signal is recorded by the pit,
These pits are formed along the recording track.

In this optical disk 101, a predetermined radial position on the inner peripheral side is a lead-in portion (read start position).
A predetermined radial position on the outer peripheral side is a lead-out portion (reading end position). That is, in the optical disc 101, a region from the lead-in section to the lead-out section is a signal recording area.

Next, the disk drive device 10 is shown in FIG.
3, a chassis 11 is provided with a disk rotation drive mechanism 14 including a spindle motor 12 and a disk table 13, an optical pickup device 15, and a pickup feed device 16. The chassis 11 is a so-called floating chassis, and is attached to a frame (not shown) of the disc player device via a damper.

As shown in FIGS. 1 to 3, the spindle motor 12 is mounted on the chassis 11 at one end. The spindle motor 12 has a drive shaft 12 a projecting upward from the chassis 11 perpendicular to the main surface of the chassis 11. This drive shaft 12a
Is supported by a bearing (not shown) provided on the chassis 11. This drive shaft 12a
The disk table 13 is attached to the tip of the. The disk table 13 is formed in a substantially disk shape, and has a truncated cone-shaped centering projection 13 at the center of the upper surface.
a is provided. When the central portion of the optical disk 101 is placed on the disk table 13, the centering projection 13a is fitted into the chucking hole 101a to perform centering (alignment) of the optical disk 101, and the peripheral edge of the optical disk 101 is positioned at the periphery. The peripheral portion of the chucking hole 101a is placed on the upper surface of the flange portion, and the optical disc 101 is positioned and held. At this time, the optical disk 101 is held by the disk table 13 with the disk substrate side facing the chassis 11 side.

When the spindle motor 12 is driven to rotate while the optical disk 101 is held on the disk table 13, the optical disk 101 is rotated.
Is rotated with the disk table 13. Further, the disk table 13 is immersed below the disk tray integrally with the chassis 11 by moving the chassis 11 downward, and in this state, the optical disk 101 on the disk table 13 is placed on the disk tray. Then, the disc can be taken out by pulling out the disc tray.

In the optical pickup device 15, an objective lens 21 can be moved in the optical axis direction (focus direction) and the direction perpendicular to the optical axis (tracking direction) by a biaxial actuator 22 on the upper surface side of a housing-like slide base 20. It is supported by. In addition, the slide base 2
0, that is, a housing portion, an optical unit including a semiconductor laser as a light source, a beam splitter, a photoelectric conversion element for receiving and detecting a reflected light beam from an optical disk, and the like are built in. Is conducted.

The optical pickup device 15
The optical disk 101 is rotated on the chassis 11 by the disk rotation drive mechanism 14.
Are movably supported in the radial direction. That is, a support hole is provided below one side of the slide base portion 20 so that the guide shaft 17 laid horizontally in the direction of the disk rotation drive mechanism 14 is inserted on the upper surface side of the chassis 11. On the upper side, a rack gear 24 having a backlash correction mechanism 23 is provided in parallel with the guide shaft 17, and this rack gear 24 is meshed with a pinion gear of the pickup feeding device 16, which will be described later.
By this driving, the optical pickup device 15 can move in the radial direction of the optical disk 101 along the guide shaft 17.

The optical pickup device 15 is
A guide groove 25 is provided on the other side of the slide base 20.
The guide shaft 17 is provided on the chassis 11.
The guide shaft 17 is slidably engaged with the guide edge 18 provided in parallel with the guide shaft 17 so as to prevent rotation of the guide shaft 17 around the axis. It is supported as a direction perpendicular to the chassis 11.

An actuator cover 26 that covers a biaxial actuator 22 that supports the objective lens 21 is fitted on the upper surface of the slide base 20. The objective lens 21 is mounted on the upper surface of the cover 26. A facing window hole 26a is provided so that the light beam emitted from the objective lens 21 is emitted outward.

A pickup feeder 16 for moving the optical pickup device 15 on the chassis 11 is constructed by connecting a spur gear transmission mechanism to a feed motor 30 which is a driving source of the pickup feed mechanism 16. Have been. That is, the feed motor 30 drive shaft 3
1, a drive gear 32 is attached. The drive gear 31 meshes with an idle gear 33 rotatably supported by the chassis 11. This idle gear 3
3, a small gear 34 is fixed coaxially.
4 meshes with a driven gear 35 rotatably supported by the chassis 11. A pinion gear 36 is coaxially mounted on the driven gear 35. The pinion gear 36 is meshed with a rack gear 24 formed on one side edge of the slide base 20 of the optical pickup device 15.

When the feed motor 30 of the pickup feed device 16 thus configured is driven to rotate, the optical pickup device 15 is moved along the guide shaft 17. Thus, the optical pickup device 15
Is moved, the optical pickup device 15 is moved over the inner and outer peripheries of the optical disc 101 held on the disc table 13. In this disk drive, the optical pickup device 15 can be moved to the outside of the lead-out position, which deviates from the signal recording area of the optical disk 101.

When the optical disc 101 is rotated by the spindle motor 12, the optical pickup device 15 reads out information signals recorded along the recording tracks of the optical disc 101 along the recording tracks.

When the optical disc 101 is rotated, the recording track is eccentric with respect to the center of curvature of the recording track (the center axis of the drive shaft 12a of the spindle motor 12). As a result, at the reading position by the optical pickup device 15, the optical disk 101 periodically reciprocates in the radial direction. Also, this optical disc 101
When the is rotated, the signal recording surface periodically changes in a direction perpendicular to the signal recording surface at the reading position by the optical pickup device 15 due to distortion (error in flatness) of the disk substrate of the optical disk 101. Reciprocate to.

In order to cope with such eccentricity and so-called surface runout in the optical disk 101, the optical pickup device 15 includes the biaxial actuator 22 as an objective lens driving unit as shown in FIG. . The biaxial actuator 22 is connected to the objective lens 2.
1 is the optical axis direction of this objective lens 21 (focus direction)
The optical disc 101 is movably supported in a direction perpendicular to the optical axis (a radial direction of the optical disc 101, a tracking direction).

That is, the optical pickup device 15
The upper surface of the slide base 20 is formed as an actuator base 20a, and the biaxial actuator 22 is supported on the actuator base 20a. The biaxial actuator 22 has a support block 41 mounted on the actuator base 20a, and a bobbin 42 also serving as a lens holder holding the objective lens 21 is mounted on the support block 41 with respect to the actuator base 20a. The bobbin 42 is supported via a resin support member 43 having a hinge portion that can swing in the vertical and parallel directions.
And a tracking coil 45 are attached. On the actuator base 20a, a pair of magnetic circuits for positioning the coils 44 and 45 in a magnetic field are provided. These magnetic circuits are
6, 46 and magnets 47, 47 attached to the yokes 46, 46.

As described above, in the biaxial actuator 22 mounted on the actuator base 20a of the slide base 20, the drive current based on the focus error signal is supplied to each of the focus coils 44, 44 so that the drive current is supplied. The bobbin 42 is moved along with the objective lens 21 in the optical axis direction of the objective lens 21. Further, each of the tracking coils 45,
When the drive current based on the tracking error signal is supplied to 45, the bobbin 42 is moved with the objective lens 21 in a direction perpendicular to the optical axis of the objective lens 21.

As described above, the two-axis actuator 22
When the objective lens 21 is moved, the focal point of the light beam on the signal recording layer 102 of the optical disk 101 by the objective lens 21 follows the periodic movement of the recording track, and is always It will be formed on the recording track.

As shown in FIG. 4, the optical unit 51 provided in the optical pickup device includes a housing portion 20b of the slide base portion 20 and a semiconductor laser 52 serving as a light source and optical components built therein. . In the optical pickup device 15, the light beam emitted from the semiconductor laser 52 passes through a grating (diffraction grating) 53, which is an optical component, and is reflected by a beam splitter (semiconductor mirror) 54 to 90 °.
The two-axis actuator 22 which is deflected and is an objective lens driving unit arranged corresponding to the optical unit 51.
Is incident on the objective lens 21 held by the bobbin 42 also serving as the lens holder. The grating 53 divides the light beam into at least three light beams (zero-order light and ± first-order light). This objective lens 21
Is opposed to the signal recording layer 102 of the optical disk 101 held on the disk table 13. The objective lens 21 transmits the incident light beam through the disc substrate to the signal recording layer 102 of the optical disc 101.
The light is condensed on top and irradiated.

The light beam condensed on the signal recording layer 102 of the optical disk 101 by the objective lens 21 that is moved and operated as described above is used for the signal recorded on the signal recording layer 102 in the signal recording layer 102. The intensity is modulated according to and reflected. The reflected light beam reflected by the signal recording layer 102 is again transmitted to the objective lens 2.
After 1, the process returns to the beam splitter 54. The reflected light beam passes through the beam splitter 54, passes through a detection lens (not shown), and is focused on a light receiving surface of a photodiode 55 as a photodetector.

The photodiode 55 has a light receiving surface divided into a plurality of portions, and outputs a light detection signal of a level corresponding to the amount of received light independently for each of the portions. By performing the arithmetic processing between the plurality of light detection signals output from the photodiode 55 in this manner,
A read signal (RF signal) of an information signal from the optical disc 101, a focus error signal, and a tracking error signal can be obtained.

The focus error signal is a signal obtained by a so-called astigmatism method.
1 and the optical disk 101
Is a signal indicating the distance in the optical axis direction of the objective lens 21 from the signal recording layer 102 of FIG. The tracking error signal is a signal obtained by a so-called three-beam method. The tracking error signal is formed in a radial direction of the optical disc 101 between a focal point of the light beam by the objective lens 21 and a recording track of the optical disc 101 (the objective lens 21). (In a direction orthogonal to the optical axis of the optical axis).

The disk drive device 10 constructed as described above is controlled as shown in the control system diagram of FIG. That is, the drive controller 61 transmits a control signal in accordance with an instruction from the drive interface to the rotation control system 62 of the spindle motor 12 and the feed motor 3.
It is supplied to a zero feed motor control system 63 and an optical pickup control system 64 to operate each of the control systems 62, 63 and 64. By this operation, the spindle motor 12 is driven to rotate to rotate the optical disk 101, and the feed motor 30 is driven to rotate and drives the optical pickup device 15 via the spur gear transmission mechanism to rotate the optical disk 101. And the optical pickup device 15 moves the objective lens 21 on the basis of a tracking error signal and a focus error signal.

The disk drive device 10 according to this embodiment includes a short circuit for short-circuiting the motor power supply between the feed motor 30 and the feed motor control system 63, that is, on the power input side of the feed motor 30. Means 66 are provided. The short-circuit means 66 is configured to be short-circuited by a signal from the feed motor control system 63 while the movement of the optical pickup device 15 is stopped and when the power of the disk drive device 10 is turned off.

As described above, the short-circuit means 66 is arranged on the power input side of the feed motor 30 so that the power input side of the feed motor 30 is stopped while the optical pickup device 15 is stopped moving and the disk drive device 10 is turned off. By short-circuiting, when the optical pickup device 15 stops moving and the disk drive device 10 falls,
When the feed motor 30 moves by its own weight along the guide shaft 17 and the guide edge 18, the feed motor 30 is rotated through the spur gear transmission mechanism. A force is generated, and the feed motor 30 is braked by the reverse starting force. For this reason, the moving speed of the optical pickup device 15 decreases, and even if the optical pickup device 15 collides with the stopper portion, the impact is reduced.

The reverse starting force generated in this motor increases as the rotation speed increases, and the braking performance increases.
When the moving speed of the optical pickup device 15 is high, that is, when the disk drive device 10 moves instantaneously when dropped, etc., the feed motor 30 is also rotated at a high speed, so that the reverse starting force becomes large. Therefore, the braking performance is increased and the optical pickup device 15 is immediately stopped from moving, so that there is almost no impact applied and there is no possibility that the characteristics are deteriorated.

The short-circuit means 66 can be realized on the system control program without increasing the number of components on the circuit of the disk drive device 10, and the cost increase is almost zero.

Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and can be variously modified without departing from the gist of the present invention. For example, the shape and the like of each member of the disk drive device can be arbitrarily changed, and the overall shape of the optical pickup device is not limited to the illustrated one, and may be formed in a flat shape. Other configurations, for example, the support member is not limited to a resin member having a hinge portion, and a support member formed in a leaf spring shape, a spring wire shape, or the like can be used.

Further, the optical pickup device according to the present invention can constitute an optical magnetic head mechanism in a recording / reproducing device for a recordable / reproducible magneto-optical disk in combination with a magnetic head device as an overwrite head.

[0046]

As described above, in the disk drive device according to the present invention, the power input side of the feed motor for moving the optical pickup device is short-circuited while the optical pickup device is not moving and the power is off. By the rotation of the feed motor caused by the movement of the optical pickup device at the time of dropping or the like, the feed motor generates a reverse starting force and is braked to prevent the movement of the optical pickup device, thereby reducing the shock applied to the optical pickup device. Characteristic degradation and the like are prevented.

The short circuit on the power input side of the feed motor is
Because it can be realized without increasing the number of parts on the circuit,
There is almost no increase in cost, and a highly reliable disk drive can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a plan view of an example of a disk drive device according to the present invention.

FIG. 2 is a side view of the disk drive device shown in FIG.

FIG. 3 is a cross-sectional view of the disk drive device shown in FIG.

FIG. 4 is a schematic configuration diagram of an example of an optical pickup device applied to a disk drive device according to the present invention.

FIG. 5 is a system diagram of an example of a disk drive device according to the present invention.

[Explanation of symbols]

10 ‥‥ disk drive unit, 11 ‥‥ chassis, 1
2 ‥‥ spindle motor, 13 ‥‥ disk table,
15 ‥‥ optical pickup device, 16 ‥‥ pickup feeder, 20 ‥‥ slide base, 21 ‥‥ objective lens, 22 ‥‥ two-axis actuator, 24 ‥‥ rack gear, 30 ‥‥ feed motor, 33 ‥‥ idle gear , 35
‥‥ Follower gear, 36 ‥‥ Pinion gear, 63 ‥‥ Feed motor control system, 66 ‥‥ Short circuit means

Claims (3)

[Claims] An optical pickup device for recording and / or reproducing an information signal on and from an optical recording medium rotationally driven by a rotational drive mechanism on a chassis is movably disposed on the chassis. A gear mechanism that is always meshed with the optical pickup device; a feed motor that moves the optical pickup device via the gear mechanism; and a feed motor that stops moving the optical pickup device. Short-circuiting means for short-circuiting the power input side of the optical pickup device. When the movement of the optical pickup device is stopped, the power input side of the feed motor is electrically short-circuited, and the feed motor is reversely started by rotation of a rotor. A disk drive device wherein the feed motor is braked by a force. 2. The disk drive device according to claim 1, wherein said gear mechanism is constituted by a spur gear and is connected to said optical pickup device by a pinion rack. 3. The short-circuit means is arranged on a power input side of the feed motor, and is electrically short-circuited when the movement of the optical pickup device is stopped and in response to a power-off signal. 2. The disk drive device according to 1.