JPH04328333A - Disk drive device - Google Patents

Abstract

PURPOSE:To easily execute what is called tangential adjustment moving an optical pickup device in the peripheral direction of an optical disk by rotating a pressure screw. CONSTITUTION:A frame 2 supporting the optical pickup device 20 is supported so that it can be slided as against a chassis 1 and the frame is pressure- supported in one direction by a flat spring 55. The pressure screw 15 is abutted on the side of the other direction so as to execute positioning.

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 for writing and/or reading information signals to and from an optical disk.

0002

2. Description of the Related Art Conventionally, optical discs have been proposed that include a disc substrate and a signal recording layer provided on the main surface of the disc substrate. The signal recording layer of this optical disc is formed of a predetermined material so that optical or magneto-optical signal recording can be performed. Writing and/or reading of information signals to and from the signal recording layer is performed by irradiating the signal recording layer with a focused light beam, or by irradiating the signal recording layer with the light beam and applying an external magnetic field.

[0003] Recording and/or reproducing information signals using such an optical disc is accomplished by a recording and/or reproducing apparatus equipped with a so-called disk drive device that includes a disk rotation drive device and an optical pickup device. This is done by

As shown in FIG. 10, the disk rotation drive device includes a disk table 103 on which a chucked portion provided at the center of the optical disk 101 is placed and holds the optical disk 101. . This disc table 103 is provided with a centering protrusion 102 for holding the optical disc 101 in a predetermined position. This disk table 103 is
It is attached to the tip side of a spindle motor 104, which is a drive shaft of a spindle motor (not shown). When the spindle motor rotates, the disk table 103 rotates the optical disk within a plane along the main surface of the optical disk, centering on the chucked portion.

The optical pickup device is configured to be able to write and/or read information signals to and from the signal recording layer of the optical disc. That is, as shown in FIG. 10, this optical pickup device has an optical block section in which a light source such as a semiconductor laser and a predetermined optical device that guides the light beam emitted from the light source are housed. An objective lens 107 is mounted on the optical block portion to condense and emit the light beam. This optical pickup device 106 collects the luminous flux emitted from the light source,
The light is condensed to a point outside the optical pickup device 106 via the objective lens 107. The optical pickup device 106 also includes a photodetector for detecting the returned light beam when the light beam emitted through the objective lens 107 is reflected by the optical disk and returns to the objective lens 107 as a light beam. have.

In the disc player device, the optical pickup device 106 is slidably supported by a guide shaft 105, as shown in FIGS. 10 and 11, and the objective lens 107 serves as a signal recording surface of the optical disc 101. It faces the main surface. By being moved along the guide shaft 105, the optical pickup device 106 can be moved in the radial direction of the optical disk 101 held on the disk table 103, over the inner and outer circumferences of the optical disk 101. It is considered possible. That is, this optical pickup device 106 is moved along the guide shaft 105 and the disk 101 is rotated, so that the optical pickup device 106 picks up signals over the entire signal recording surface of the optical disk 101 through the objective lens 107. The information signal can be written and/or read over the entire surface of the signal recording surface.

[0007]

By the way, in the disk drive device as described above, as shown in FIG. If it does not intersect with the axis of the optical disc 104, it is impossible to write and/or read information signals to and from the signal recording surface of the optical disc 101 in a satisfactory manner.

That is, in this way, the objective lens 1
07 does not intersect with the axis of the spindle shaft 104, the optical pickup device 106
When the optical disc 101 is moved around the inner and outer peripheries of the optical disc 101, the direction of the tangent of the recording track formed on the signal recording layer to the optical pickup device 106 changes. The direction of the tangent to the recording track at the position where the objective lens 107 faces is
The change occurs depending on the angle between a straight line passing through the axial center of the spindle shaft 104 and parallel to the movement locus of the optical pickup device 106 and a straight line connecting the axial center of the spindle shaft 104 and the optical axis of the objective lens 107. Because it does.

In this way, when the direction of the tangent to the recording track at the position facing the objective lens 107 changes, the optical pickup device 106 generates a tracking error signal using the so-called three-beam system. In this case, it becomes impossible to obtain a good tracking error signal, and it becomes impossible to write and/or read information signals on the signal recording surface of the optical disc 101 in a good manner.

[0010] In a conventional disk drive device,
In order to perform so-called tangential adjustment in which the extension line of the movement locus of the objective lens 107 intersects the axis of the spindle shaft 104, the mounting position of the guide shaft 105 is adjusted. However, such adjustment work is complicated, making it difficult to facilitate the manufacture of disk drive devices.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned circumstances, and an object of the present invention is to provide a disk drive device that allows so-called tangential adjustment to be easily performed and is easy to manufacture.

0012

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the above-mentioned objects, a disk drive device according to the present invention includes a chassis in which a disk table for holding a recording disk is disposed, and a a frame that is slidably supported along the upper surface of the chassis and supports an optical pickup device; an elastic biasing means that elastically biases the frame in one direction in which the frame can slide; and a slide of the frame. positioning means for positioning the frame by abutting on the other side of the possible direction; The position is adjusted by being moved relative to the chassis.

[0013]

[Operation] In the disk drive device according to the present invention, the frame, which is supported on the chassis so as to be slidable along the upper surface of the chassis and also supports the optical pickup device, is moved in one direction in the slidable direction by the elastic biasing means. Elastically biased, the positioning means is brought into contact with and positioned on the other side of the slidable direction, and the positioning means is moved relative to the chassis, thereby being disposed on the chassis. The circumferential positioning of the recording disk held on the disk table is adjusted.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the disk drive device according to the present invention is a device into which an optical disk 101, which is a recording disk, is loaded and writes and/or reads information signals to and from the optical disk 101.

The optical disc 101 includes a disc-shaped disc substrate made of a transparent synthetic resin such as polymethyl methacrylate or polycarbonate, and a signal recording layer formed on the main surface of the disc substrate. . This optical disc is capable of writing and/or reading information signals to and from the signal recording layer by irradiating the signal recording layer with a condensed laser beam or the like, or by irradiating the laser beam and applying an external magnetic field. It is configured so that it can be done.

[1] Overview of the disk drive device according to the present invention This disk drive device is configured with a chassis 1, as shown in FIGS. 1, 8, and 9. This chassis 1 is fixedly disposed within an outer casing (not shown) of a recording and/or reproducing device to which this disk drive device is applied, via a mounting member such as a vibration absorber. This chassis 1
A spindle motor 41 is attached to the lower surface side. This spindle motor 41 has a spindle shaft 42, which is a drive shaft, projected to the upper surface side of the chassis 1 through a through hole provided in the chassis 1. The spindle shaft 42 is substantially perpendicular to the chassis 1.

A disk table 43 is attached to the spindle shaft 42 . The disc table 43 is made of a material such as metal and is formed into a disc shape corresponding to the center portion of the optical disc 101. This disk table 43 has its center portion attached to the tip side of the spindle shaft 42, and is supported with its main surface substantially parallel to the chassis 1.

A centering member 44 is provided at the center of the upper surface of the disk table 43. This centering member 44 is formed into a substantially truncated conical shape with a diameter reduced on the upper side. This centering member 44 is attached to the spindle shaft 42 by the disc table 43.
The disk table 43 is supported so as to be movable within a predetermined range in the axial direction of the disk table 43, and is capable of moving in and out of the upper main surface of the disk table 43. Further, this centering member 44 is elastically biased in the direction of protruding upward from the disk table 43 by a coil spring (not shown) provided within the disk table 43. This centering member 44 is formed in a size that allows it to be inserted halfway into a center hole for chucking provided at the center of the optical disc 101. That is, this centering member 44 brings the center of the optical disc 101 into alignment with the spindle axis by bringing the conical outer peripheral surface into contact with the inner peripheral part of the center hole of the optical disc 101 placed on the disc table 43. A so-called centering operation is performed to match the central axis of 42. This disk table 43 is
The central portion of the optical disc 101 is clamped and held in cooperation with a chucking member (not shown) disposed opposite to the upper surface of the optical disc 101 .

A friction member 45 is attached to the upper main surface of the disk table 43. As shown in FIG. The friction member 45 is formed of a material such as rubber into a thin annular sheet that surrounds the centering member 44 . When the optical disc 101 is placed on the disc table 43, this friction member 45 is interposed between the disc table 43 and the optical disc 101, and is inserted between the disc table 43 and the optical disc 101. This is to prevent slipping.

A frame 2 for supporting an optical pickup device 20 is disposed on the chassis 1. The frame 2 is made of a material such as metal and has a substantially rectangular housing shape with an open top side. This frame 2 is disposed with one longitudinal side portion near the disk table 43. As shown in FIG. A pair of first and second frame support pins 3 and 4 are implanted in the outer portions of both sides of the frame 2 in a corresponding manner. These frame support pins 3 and 4 are provided approximately in the longitudinal center of the frame 2 so as to be aligned with each other with the frame 2 interposed therebetween. These frame support pins 3 and 4 are inserted into corresponding support pin insertion holes 6 and 8 of first and second frame support pieces 5 and 7 which are provided as a pair on the chassis 1. As a result, it is supported parallel to the chassis 1. That is, each of the frame support pieces 5 and 7 is formed in substantially the same shape as each other, and faces each other on the chassis 1 with an interval slightly wider than the width of the frame 2. Further, the support pin insertion holes 6 and 8 are formed so as to be aligned with each other. The above frame 2 is
The frame support pins 3 and 4 are supported by the frame support pieces 5 and 7, so that the frame support pins 3 and 4 are centered on the chassis 1 as shown by arrow E in FIG. The chassis 1 is rotatably supported such that one longitudinal side portion and the other longitudinal side portion thereof are moved toward and away from the chassis 1 .

Note that each of the frame support pins 3 and 4 is provided with a mechanism to prevent movement of the frame support pins 3 and 4 in the direction perpendicular to the axis within the support pin insertion holes 6 and 8, that is, so-called play. One end side of the tension coil springs 9, 10 is hooked correspondingly to each other. Each of these tension coil springs 9 and 10 has its other end hooked to corresponding spring hook pieces 11 and 12 provided on the chassis 1, and the frame 2 is As shown by arrow B, the frame support pins 3 and 4 are elastically biased in one direction perpendicular to their axes. Each of the frame support pins 3 and 4 is pressed and supported in one direction against the inner surface of each of the support pin insertion holes 6 and 8 by each of the tension coil springs 9 and 10, and is prevented from moving in a direction perpendicular to the axis. ing.

[2] Structure of the optical pickup device And on the frame 2, as shown in FIGS. 1 and 9,
An optical pickup device 20 is provided. This optical pickup device 20 has an optical block section, and is configured with a light source such as a semiconductor laser, a predetermined optical device that guides the light beam emitted from the light source, a photodetector, etc. built into the optical block section. There is. The optical pickup device 20 also includes an objective lens drive device 21 attached to the upper surface of the optical block. This objective lens driving device 21 supports the objective lens 22 so as to be movable in two directions: an optical axis direction of this objective lens 22 and a direction perpendicular to this optical axis.
2 in the two axial directions. This electromagnetic drive mechanism includes a feeding coil attached to a lens bobbin that is integrated with the objective lens 22, a magnetic circuit that links magnetic flux to the feeding coil, and the like. This objective lens driving device 21 is
The objective lens 22 is supported in the optical path of the light beam emitted from the optical block section.

In this optical pickup device 20, the light beam emitted from the optical block section is incident on the objective lens 22. The light flux incident on the objective lens 22 is focused and irradiated onto the signal recording layer of the optical disc 101 placed on the disc table 43. The light beam reflected by this signal recording layer enters the objective lens 22 again, returns to the optical block section, and is detected by the photodetector.

The optical pickup device 20 is supported movably on the frame 2 by first and second support shafts 24 and 25, which are provided as a pair and parallel to each other on the frame 2. There is. Each of the support shafts 24 and 25 is pressed and supported at both ends of the frame 2 by shaft pressing plates 28, 29, 30, and 31, so that the support shafts 24 and 25 extend in the longitudinal direction of the frame 2. installed on. Each of the shaft holding plates 28, 29, 30, 31 is secured by set screws 28a, 29a, 30a, 31a, respectively.
It is attached to the frame 2 above. The optical pickup device 20 has the first support shaft 24 inserted through a shaft insertion hole 26 provided on one side of the optical block, and a guide roller attached to the other side of the optical block. 27 to the second above
By rolling it onto the support shaft 25, movement in the direction along each of these support shafts 24, 25 is possible. The direction in which the optical pickup device 20 moves along each of the support shafts 24 and 25 is the direction in which it moves toward and away from the disk table 43.

The frame 2 is provided with a feeding mechanism for moving the optical pickup device 20. This feed mechanism includes a feed motor 32 attached to the lower surface side of the frame 2, and a feed motor 32 attached to the lower surface side of the frame 2.
The optical pickup device 20 includes a plurality of reduction gears and a timing belt that transmit the driving force of the optical pickup device 20 to the optical pickup device 20.

That is, a drive gear 33 is attached to the drive shaft of the feed motor 32. This drive gear 3
3 meshes with a large-diameter gear portion of a first reduction gear 34 that is rotatably supported by the frame 2 via a support shaft 34a. The small diameter gear portion of the first reduction gear 34 is connected to a second reduction gear 35 which is pivotally supported on the frame 2 via a support shaft 35a.
It meshes with the large diameter gear part. The small-diameter gear portion of the second reduction gear meshes with a gear portion of a pulley gear 36 that is supported by the frame 2 via a support shaft 36a and positioned on the other side in the longitudinal direction of the frame 2. A timing belt 38 is wrapped around the pulley portion of the pulley gear 36. The timing belt 38 is stretched between the pulley portion of the pulley gear 36 and a pulley 37 provided on one side of the frame 2 in the longitudinal direction. This pulley 37 is pivotally supported by a support shaft 37a. A support shaft 37a that pivotally supports the pulley 37 is provided on a pulley support arm 39 rotatably supported by the frame 2 via a support shaft 40.

The pulley support arm 39 is connected to a spring locking piece 39 provided on the pulley support arm 39.
A tension coil spring 56 stretched between the support shaft 37a and a spring locking piece 57 provided on the chassis 2 rotates and biases the support shaft 37a in a direction away from the pulley gear 36. That is, the timing belt 38 is kept in a tight state by the biasing force of the tension coil spring 56. A portion of the timing belt 38 extending between the pulley gear 36 and the pulley 37 is attached to one side of the optical block portion of the optical pickup device 20. Therefore, when the feed motor 32 is rotationally driven, the optical pickup device 20 rotates the support shafts 24 as shown by arrows T in FIGS. 1 and 9, depending on the direction of rotation of the feed motor 32. , 25.

A tilt sensor 23 is attached to the upper surface of one side of the optical block portion of the optical pickup device 20. As shown in FIG. The tilt sensor 23 includes a light emitting element and a light receiving element. This tilt sensor 23 is
The optical disc 101 placed on the disc table 43 is irradiated with a light flux for tilt detection by the light emitting element, and the light flux reflected by the optical disc 101 of the light flux for tilt detection is detected by the light receiving element. It is configured. In this tilt sensor 23, the light detection output outputted from the light receiving element is a signal corresponding to the tilt of the objective lens 22 with respect to the optical axis of the portion of the signal recording layer of the optical disc 101 facing the objective lens 22, that is, , which is the tilt detection signal. This tilt detection signal is sent to a control device (not shown) of a recording and/or reproducing device to which this disk drive device is applied.

In this disk drive device, the optical disk 101 is held on the disk table 43 and rotated together with the disk table 43, and the optical pickup device 20 is operated to rotate the optical disk held on the disk table 43. By carrying out the feeding operation over the inner and outer peripheries of the optical disc 101, substantially the entire signal recording surface of the optical disc 101 can be irradiated with the light beam emitted through the objective lens 22. Therefore, the optical pickup device 20 can write and/or read information signals over the entire signal recording surface of the optical disc 101.

[3] Structure of the tangential adjustment mechanism The frame 2 is attached to the chassis 1 in the axial direction of the frame support pins 3 and 4, that is, the support shafts that support the optical pickup device 20. 24,
A tangential adjustment mechanism is provided for movement adjustment in a direction perpendicular to the axis of 25. This tangential adjustment mechanism includes a leaf spring 55 which is provided on the chassis 1 and serves as an elastic biasing means, and a press screw 15 which is attached to the chassis 1 and serves as a positioning means.

The leaf spring 55 has its proximal end mounted on the chassis 1 at a position near one side of the frame 2, and its distal end attached to the one side of the frame 2. It is in contact with it. This leaf spring 55 extends around the first frame support pin 3 of the frame 2 along the axial direction of each of the frame support pins 3 and 4, as shown by arrow F in FIG. The frame 2 is pressed in the direction of the other side to urge the frame 2 to move in the direction of the other side. A side wall portion 13 is provided on the chassis 1 so as to face the side surface portion on the other side of the frame 2. A screw hole 14 is provided in this side wall portion 13 at a position facing the tip of the second frame support pin 4 . The press screw 15 is screwed into this screw hole 14 . This press screw 15 has its tip abutted against the tip of the second frame support pin 4 . The tips of these press screws 15 and the tips of the second frame support pins 4 are pressed against each other by the urging force of the leaf spring 55.

In this tangential adjustment mechanism, the pressing screw 15 is rotated relative to the side wall 13 of the chassis 1, and the amount of protrusion of the pressing screw 15 from the side wall 13 toward the frame 2 is adjusted. By variably adjusting the frame 2, as shown by arrow G in FIG.
The axial position of each of the frame support pins 3 and 4 can be moved and adjusted. The tangential adjustment performed in this manner is adjusted so that the axial center of the spindle shaft 42 intersects with the extension of the movement locus of the optical axis of the objective lens 22. That is, this tangential adjustment is performed by a straight line passing on the optical axis of the objective lens 22 and parallel to each of the support shafts 24 and 25, as shown by arrow D in FIG. The distance D from a straight line parallel to each support shaft 24, 25 is adjusted to be zero.

By the way, the amount of movement of the frame 2 by the press screw 15 is ±1 around the reference position.
It is made to be about mm. When the optical pickup device 20 is configured to generate a tracking error signal using a so-called three-beam system, the optical pickup device 20 outputs a tracking error signal to the optical disc 1.
A main beam for writing and/or reading information signals to and from recording tracks formed on the signal recording layer of No. 01, and first and second beams forming a pair on both sides of this main beam.
A sub-beam is emitted. The sub-beams and the main beam are emitted so as to diverge within one plane by the action of, for example, a diffraction grating, and form beam spots arranged in a straight line on the signal recording surface. When the main beam is irradiated onto the recording track, each of the sub-beams is irradiated at positions shifted by the same predetermined distance in directions opposite to each other with respect to the recording track.

[0034]The distance between the beam spot formed by the main beam and the beam spot formed by the sub-beam on the signal recording layer is as follows:
The thickness is set at 20 μm. Further, the distance from the beam spot formed by the sub-beam to the center of the recording track on the signal recording surface is set to 1/4 of the pitch of the recording track. If the pitch of the recording track is 1.6 μm, the distance between the beam spot formed by the sub-beam and the center of the recording track is 0.4 μm. Therefore, the angle α between the straight line connecting each beam spot on the signal recording surface and the tangent to the recording track is 0.02ra.
d is the reference value.

Then, each guide shaft 24 of the objective lens 22 is positioned at a distance r from the center of the optical disc 101 on the signal recording surface of the optical disc 101.
, 25 and a straight line connecting the optical axis of the objective lens 22 and the center of the optical disk 101 is an angle θ, this angle θ is expressed as θ=D/r. When the innermost circumference of the signal recording surface of this optical disc 101 is r1 and the outermost circumference is r2, the above angle θ (θ1) at the innermost circumference and the above angle θ (θ2) at the outermost circumference of this signal recording surface are The angular difference Δθ is Δθ=
It is expressed as (θ1 −θ2 )=D(1/r1 −1/r2 ). Therefore, the radius of the optical disk 101 is 150×103 μm, the innermost circumference of the signal recording surface of this optical disk 101 is 40×103 μm, and the outermost circumference is 150×103 μm.
0x103 μm, and the distance D is 0.45x1
03 μm, the change Δθ in the above angle θ from the innermost circumference to the outermost circumference of this signal recording surface is as follows: Δθ=0.45×10−3 {1/(40×10−3)−
1/(150×10-3)} ≒0.0082(
rad). Then, the phase difference δ of the signals obtained from each beam spot of each sub-beam is as follows: δ=180°×Δθ/α=180°×0.0082/0
．． 02=74.2°. Therefore, if the thread pitch of the press screw 15 is 0.45 mm, by rotating the press screw 15 once, the phase difference δ of 74.2° can be adjusted. By moving the press screw 15 by 1 mm, the phase difference δ of 165° can be adjusted.

[4] Configuration of skew servo mechanism and
A skew servo mechanism is disposed on the chassis 1 to adjust the inclination of the frame 2 with respect to the chassis 1. As shown in FIGS. 1 and 2, this skew servo mechanism includes a skew servo motor 4 disposed on the chassis 1 and driven and controlled by the control device.
6 and a cam mechanism for transmitting the driving force of the skew servo motor 46.

The skew servo motor 46 is attached to a motor support plate 47 attached to the chassis 1, and is disposed on the chassis 1 at a position near the disk table 43. This skew motor 4
6 is supported with a drive shaft 46a substantially parallel to the chassis 1. A worm gear 48 is attached to the six drive shafts 46a of the skew motor 46. This worm gear 48 is mounted on a support shaft 49a on the chassis 1.
The worm wheel 49 is engaged with a worm wheel 49 which is pivotally supported through the worm wheel 49. A transmission gear 49b is integrally formed coaxially with the worm wheel 49. This transmission gear 49b
meshes with a gear portion 50b of a cam gear 50 that is pivotally supported on the chassis 1 via a support shaft 50a. That is, in this skew servo mechanism, the cam gear 50 is rotated by the rotation of the skew servo motor 46.

The cam gear 50 has the gear portion 50b formed on its outer periphery, and an end cam 51 integrally formed on its upper main surface. A copying pin 19 is placed and engaged with the upper end of the end cam 51, which is installed parallel to the chassis 1 on one side of the frame 2 in the longitudinal direction. As shown in the cam diagram in FIG. 5, this end cam 51 has an inclined cam shape, and when the cam gear 50 is rotated, the copying pin 19 is moved toward and away from the chassis 1. Perform movement operations.

A tension coil spring 16 is tensioned between the vicinity of the side surface of the frame 2 on one side in the longitudinal direction and the chassis 1 for pressing the copying pin 19 against the upper end surface of the end cam 51. It is suspended. That is,
The tension coil spring 16 has one end hooked to a spring hook 17 provided on one longitudinal side of the frame 2, and the other end hooked to a spring hook 18 provided on the chassis 1. By being hooked, the frame 2 is attached to the copying pin 1 as shown by arrow C in FIGS. 1 and 8.
9 is biased to rotate in a direction in which it is brought into pressure contact with the upper end surface of the end cam 51.

As shown in the cam diagram in FIG. 5 and in FIG. 2, the end cam 51 has a projecting piece 51a.
The portion other than 1a serves as a cam portion for moving and operating the copying pin 19. Of this cam part, Fig.
In order to prevent collision between the copying pin 19 and the protruding piece 51a, the portion near the protruding piece 51a indicated by the middle arrow M and the arrow K is set as an unused area that is not used in the operation of the skew servo. ing. Therefore, in the operation of the skew servo, the copying pin 19 is moved at a portion near the center of the cam portion shown by arrow J in FIG. 5. Then, the copying pin 19 of the cam portion
The moving portion is a linear cam with a predetermined height difference, as shown by arrow H in FIG.

The gear portion 50b of the cam gear 50 is provided with a toothless portion 54. As shown in FIGS. 3 and 4, this toothless portion 54 faces the transmission gear 49b when the end cam 51 is at a rotation angle position where each unused area contacts the copying pin 19. It is formed to do so. That is, the end cam 51 is connected to the copying pin 1.
When the rotational angle position is such that each unused area contacts the cam gear 9, the cam gear 5 from the transmission gear 49b
0 is cut off, and the end cam 51
is prevented from being rotated until the protruding piece 51 comes into contact with the copying pin 19. That is, this toothless portion 54 is formed corresponding to the area indicated by arrow P in the cam diagram of FIG. In addition, in the cam diagram of FIG. 5, the shape of the cam part and the toothless part 5 are
4, the copying pin 19 and the transmission gear 49b.
are shown as being provided at the same angular position with respect to the cam gear 50.

Further, the cam gear 50 has a protruding portion 52 formed on its lower surface facing the chassis 1 over an angular range corresponding to the toothless portion 54 . The protruding portion 52 is formed so as to come into contact with a cam return spring 53 mounted on the chassis 1 when the cam gear 50 rotates. The cam return spring 53 is
It has a leaf spring, and its base end side is supported by the chassis 1,
The leading end side is inserted between the lower surface of the cam gear 50 and the chassis 1. The direction in which the cam return spring 53 can be bent is parallel to the chassis 1. As shown in FIGS. 3 and 4, these protrusions 52 and the cam return spring 53 are mutually connected to each other when the cam gear 50 is at a rotation angle position in which the toothless portion 54 faces the transmission gear 49b. It is arranged in a position where it comes into contact.

Therefore, as shown in FIG. 3, the transmission gear 49b is rotated in one direction indicated by arrow U in FIG.
When the cam gear 50 is rotated in the other direction indicated by the arrow V in FIG. Press to displace. At this time, the cam return spring 53 presses the protruding portion 52 with its elastic force, causing the cam gear 50 to engage the gear portion 50b with the transmission gear 49b as shown by arrow W in FIG. Forces rotation in one direction. Further, as shown in FIG. 4, the transmission gear 49b is rotated in the other direction shown by arrow Q in FIG. 4, and the cam gear 50 is rotated in one direction shown by arrow R in FIG. The portion 54 is the transmission gear 4
9b, the protruding portion 5
2 presses and displaces the cam return spring 53. At this time, the cam return spring 53 presses the protruding portion 52 with its elastic force, and as shown by arrow S in FIG.
Rotation bias is applied in the other direction to mesh with 9b.

[0044] Furthermore, the chassis 1 of the cam gear 50
As shown in FIGS. 6 and 7, an optical detection section 60 is provided on the lower surface portion facing the. On the chassis 1, there is an optical detection section 60 on the lower surface of the cam gear 50.
An optical sensor 61 is provided so as to face the. The optical detection section 60 is provided over an angular range corresponding to an angular range in which the cam gear 50 contacts the copying pin 19 with a portion of the end cam 51 other than each unused area. The portion within the angle range and the portion outside the angle range are made to have different light reflectances. The optical sensor 61 is configured to irradiate the lower surface of the cam gear 50 with a light beam and to detect the amount of light reflected from the lower surface of the cam gear 50. A detection signal from this optical sensor 61 is sent to the control device. Therefore, the control signal causes the cam gear 50 to abut one of the unused areas of the cam part against the copying pin 19, as shown in FIG. 6, based on the detection signal sent from the optical sensor 61. Detects that the rotation angle position has been reached. At this time, the control device stops the rotation of the skew servo motor 46.

In this skew servo mechanism, when the skew servo motor 46 is rotationally driven, the copying pin 19 is moved within a distance range corresponding to the height difference H of the cam portion shown by the arrow H in FIG. Then, the frame 2 is rotated about the frame support pins 3 and 4 as shown by arrow E in FIG. Further, even when the cam gear 50 reaches a rotational angle position where the unused area of the cam portion contacts the copying pin 19, the cam gear 50 is moved between the gear portion 50b and the transmission gear 49b by the cam return spring 53. Since the skew servo motor 46 is rotatably biased in the direction in which they mesh, when the skew servo motor 46 is rotationally driven in the return direction, the frame 2 is smoothly returned to the state in which the frame 2 is rotated.

The skew servo motor 46 is controlled by the control device during the skew servo operation.
The drive is controlled based on the tilt detection signal sent from the tilt sensor 23. That is, in this disk drive device, the frame 2 is rotated by the skew servo motor 46 via the cam gear 50, etc., so that the angle indicated by arrow A in FIG. The angle between the optical axis of the optical disc 101 and the normal line at the point where the optical axis of the objective lens 22 intersects with the signal recording surface of the optical disc 101 is zero. Therefore, due to this skew servo operation, the light beam emitted from the objective lens 22 is always irradiated perpendicularly to the signal recording surface of the optical disc 101.

By the way, in this disk drive device, each of the frame support pins 3 indicated by the arrow L in FIG.
, 4 to the point of contact between the end cam 51 and the copying pin 19 is 73.29 mm. The height difference H of the cam portion of the end cam 51 is as follows:
It is set to 6.38mm. Therefore, cam gear 5
The rotatable angle β of the frame 2 according to 0 is tanβ
= (6.38/73.29), β≈5°. That is, the frame 2 is capable of adjusting the inclination angle with respect to the chassis 1 by ±2.5° centering on the reference angular position.

In this disk drive device, the number of teeth of the worm gear 48 is 1, the number of teeth of the worm wheel 49 is 60, and the number of teeth of the transmission gear 49 is 1.
The number of teeth of a is 15, and the gear portion 50b of the cam gear 50 is
Assuming that the number of teeth is 75, one rotation of the worm gear 48 is reduced to 1/250 rotation in the cam gear 50. Further, the portion of the cam portion of the end cam 51 shown by arrow J in FIG. 5 excluding the unused area is 226.92
It is formed over an angular range of . By the way, assuming that this cam portion is formed over the entire circumference of the end cam 51, when the cam gear 50 makes one revolution, the frame 2 will be 2.5×2/(226.92/
360) = 7.9323°. Assuming that the skew servo motor 46 is a so-called stepping motor and is capable of controlling the rotational angle position of the drive shaft every 1/3 rotation, that is, every 120 degrees, the skew servo motor 46 The inclination angle Δβ of the frame 2 caused by the rotation of the step is Δβ
=7.9323/(3×250)=0.0106≒0.
It becomes 01°. That is, the skew servo motor 4
6 can control the rotation of the frame 2 in units of 0.01°.

Furthermore, the skew servo motor 46 has the following features:
For example, with a power supply voltage of 8V, a rotation speed of 8800 rpm can be obtained. Therefore, this skew servo motor 46 moves the cam gear 50 into two parts corresponding to the cam part.
The time x required to perform a rotation operation over an angular range of 26.92° is x = {(226.92/360) x 250}/(880
0/60)=1.07 (sec). That is, the skew servo motor 46 is
The frame 2 can be rotated by 5 degrees in 1.07 seconds.

[0050]

As described above, in the disk drive device according to the present invention, the frame supported on the chassis so as to be slidable along the upper surface of the chassis and supporting the optical pickup device is elastically biased by the elastic biasing means. The slider is elastically biased in one direction of the slidable direction, and is positioned by being brought into contact with the positioning means on the other side of the slidable direction, and the positioning means is operated to move with respect to the chassis. The circumferential positioning of a recording disk held on a disk table disposed on the chassis is adjusted.

Therefore, in this disk drive device, so-called tangential adjustment can be easily performed by moving the positioning means with respect to the chassis. As the positioning means, for example, a screw screwed into the chassis can be used, and the tangential adjustment can be performed by adjusting the rotation of the screw.

That is, the present invention can provide a disk drive device in which so-called tangential adjustment can be easily performed and manufacturing is facilitated.

[Brief explanation of the drawing]

FIG. 1 is a reduced exploded perspective view showing the configuration of a disk drive device according to the present invention.

FIG. 2 is an enlarged perspective view of essential parts showing the configuration of a cam mechanism of the disk drive device.

FIG. 3 is an enlarged plan view showing the configuration of a cam gear that constitutes the cam mechanism.

FIG. 4 is an enlarged plan view showing the cam gear in a rotated state.

FIG. 5 is a cam diagram showing the configuration of the cam gear.

FIG. 6 is an enlarged plan view showing the configuration of the lower surface side of the cam gear as seen from the upper surface side.

FIG. 7 is an enlarged plan view showing the state of the lower surface side when the cam gear rotates as seen from the upper surface side.

FIG. 8 is a side view showing the configuration of the disk drive.

FIG. 9 is a plan view showing the configuration of the disk drive device.

FIG. 10 is a side view showing the configuration of a conventional disk drive device.

FIG. 11 is a plan view showing the configuration of a conventional disk drive device.

[Explanation of symbols]

1......Chassis 2...Frame 3, 4...Frame support pin 15...
・・・・・・・・・Press screw 19・・・・・・・・・・・・
- Copying pin 20...... Optical pickup device 22... Objective lens 43
・・・・・・・・・Disc table 50...
・・・・・・・・・Cam gear 51・・・・・・・・・・
...End cam 55...Plate spring

Claims (1)

[Claims] 1. A chassis provided with a disk table that holds a recording disk; a frame supported on the chassis so as to be slidable along the upper surface of the chassis; and a frame that supports an optical pickup device; an elastic biasing means for elastically biasing the frame in one direction in the slidable direction; and a positioning means for positioning the frame by abutting on the other side of the frame in the slidable direction, the frame A disk drive device in which the slidable direction is the circumferential direction of a recording disk held on the disk table, and the positioning means is adjusted by moving with respect to the chassis.