JP3533298B2 - Disc playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM,
The present invention relates to a disc reproducing apparatus for reproducing an optical disc such as a VD (Digital Versatile Disc) -ROM, and more particularly to a skew adjustment mechanism. 2. Description of the Related Art In a disk drive for reproducing a high-density recorded optical disk such as a CD-ROM drive or a DVD drive, the perpendicularity (skew) of the optical axis of the optical pickup to the disk surface is large for the disk reading performance. Affect. Particularly, in the case of a disk drive for reproducing a high-density DVD disk, strict skew accuracy is required. The factors affecting such skew include the inclination between the optical axis of the pickup and the guide axis, the inclination between the pickup guide axis and the chassis reference plane, the inclination between the chassis reference plane and the disk motor mounting surface, The inclination between the motor mounting surface and the motor shaft, the inclination between the motor shaft and the disk table surface, and the like are determined by the accumulation of the accuracy of these components. However, since there is a limit in the precision of these parts, there is also a limit in the skew precision that can be ensured. Further, even if it is possible to increase the component accuracy before the skew accuracy is obtained, the product cost will rise due to an increase in processing cost. [0005] As described above, in a disk reproducing apparatus for reproducing a high-density optical disk, the perpendicularity of the optical axis of the optical pickup with respect to the disk surface is an important factor influencing the reading performance. However, there is a problem that the verticality that satisfies the requirement cannot always be obtained due to tolerances in the accuracy of individual parts. SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a disk reproducing apparatus capable of obtaining a required perpendicularity of an optical axis of an optical pickup with respect to a disk surface without depending on an improvement in precision of individual parts. It is intended to provide equipment. [0007] To achieve the above object, resolving means for the problems], the disc reproducing apparatus of the present invention includes a chassis, and two guide shafts both ends to the chassis is supported, respectively, wherein An optical pickup supported on each guide shaft so as to be freely transportable, and at least three of the four support points of each guide shaft.
An adjusting member for adjusting One of the heights from the reference plane of the chassis of the supporting points individually, taken up in the optical pickup
Attached rack gear, and the rack gear
To transport the optical pickup along each of the guide shafts
Pickup feed motor, which is a power source for the
Power for the pickup feed motor
One or more pickups for transmitting
And a gear for feeding the rack gear.
The pickup feed gear meshing with the rack gear
To the teeth, by adjusting the height of the guide shaft by the adjustment member
Between the rack gear and the pickup feeding gear
Absorbs relative inclination to compensate for meshing between these gears
It is characterized in that a corrective taper is provided . According to the present invention, by using each adjusting member, 2
The skew can be easily adjusted by individually adjusting the heights of at least three ends of the guide shaft of the book, without depending on the improvement of the accuracy of individual parts.
The required perpendicularity of the optical axis of the optical pickup with respect to the disk surface can be obtained. The adjusting member is, for example, rotatably mounted on a chassis, supports the end of the guide shaft with a spiral cam surface, and adjusts the height of the support point of the guide shaft from the chassis reference plane depending on the rotational position. The one configured to be adjustable is exemplified. By using such an adjusting member, the height of each end of the guide shaft can be adjusted by the amount of rotation of the adjusting member, and the skew adjustment operation can be made more efficient. Also, by fixing the height of one of the four support points of each guide shaft from the chassis reference plane,
Skew adjustment can be performed based on the height of the support point at the end of the guide shaft. Further , according to the present invention, when the guide shaft is inclined with respect to the reference surface of the chassis, that is , the rack gear mounted on the optical pickup and the rack gear are mounted on the chassis.
Even when the engagement with the pickup feed gear is twisted in the tooth width direction, the normal engagement between the gears is ensured by the taper. Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the disk reproducing apparatus according to the present embodiment is configured such that a tray 1 on which a disk is mounted can be freely inserted into and removed from a main chassis 2 as a drive main body. Guide protrusions 1a are provided on both side surfaces of the tray 1. These guide protrusions 1a are fitted into guide portions 2a provided on the main chassis 2, whereby the tray 1 is guided in a linear direction parallel to the disk surface, and the tray discharge position shown in FIG. Conveyed to and from the position. As shown in FIGS. 1 to 3, the main chassis 2 includes a reproducing mechanism constructed by supporting a mechanical chassis 3 having a disk reproducing mechanism via a plurality of damping members 4 such as a damper rubber. Unit 5 is arranged. On the mechanical chassis 3, a disk motor 13, an optical pickup 14, an optical pickup feed mechanism, and the like are mounted. The disk motor 13 is fixed on the mechanical chassis 3 via a motor mount 15. Disk motor 13
A turntable 16 is attached to the motor shaft. As shown in FIGS. 3 and 4, rotating shafts 6 are protruded from both sides on the rear side in the tray insertion direction of the reproducing mechanism unit 5, and these rotating shafts 6 are main. It is rotatably held by a shaft holder 7 (see FIGS. 1 and 2) of the chassis 2. A rotation guide shaft 8 protrudes from the surface of the reproduction mechanism unit 5 on the labor side in the tray insertion direction. The rotation guide shaft 8 is provided on a guide 9 provided on a slider 9 that slides in the depth direction in FIG. The slider 9 is inserted and held in the groove 10, and is guided in the vertical direction (the thickness direction of the disk) along the guide groove 10 as the slider 9 moves. Thus, the reproduction mechanism unit 5 is configured to tilt about the rotation shaft 6 as a fulcrum and perform disc clamping. As shown in FIGS. 1 and 2, the main chassis 2 is provided with a clamper 1 via a clamper holder 11.
2 are held. Further, a mechanism system for tray loading and disk clamping is provided in the main chassis 2. Next, details of the tray loading and disc clamping mechanism and its operation will be described. FIG. 5 shows the state when the tray is discharged, FIG. 6 shows the state when the tray loading is completed, and FIG. 7 shows the state when the disk clamp is completed. In FIG. 5, reference numeral 21 denotes a loading motor.
The power is transmitted to the tray load gear 26 through the belt 23, the second pulley 24, and the reduction gear 25. A rack 27 provided on the tray 1 is meshed with the tray load gear 26, whereby the tray 1 is loaded in the arrow X direction. A slider transport gear 28 is meshed with the tray load gear 26. However, the slider transport gear 28 is not engaged with the rack 29 of the slider 9 during the loading period of the tray 1. As shown in FIG. 6, when the tray 1 is loaded to a predetermined position in the main chassis 2, the guide pin 31 of the slider 9 enters the guide groove 30 provided on the back surface of the tray 1, and the guide groove 31 Guide pin 3 by 30
With the guidance of No. 1, the slider 9 slides in the arrow Y direction.
The movement of the slider 9 causes the rack 29 of the slider 9 to move.
Are engaged with the slider transport gear 28, and the slider 9
Is further slid in the Y direction by the power of the loading motor 21. At this point, tray load gear 26 and tray 1
Is disengaged from the rack 27, and the loading of the tray 1 ends. Also, by the movement of the slider 9, as shown in FIG. 4, the rotation guide shaft 8 of the reproducing mechanism unit 5 is guided upward along the guide groove 10 of the slider 9, so that the reproducing mechanism unit 5 rotates. It rotates in the direction of arrow R with the shaft 6 as a fulcrum. During the rotation of the reproducing mechanism unit 5, the disc D mounted on the tray 1 is lifted from the tray 1 by the turntable 16. Thereafter, due to the approach between the disc chuck portion 32 of the turntable 16 and the clamper 12, the disc chuck portion 32 is completely fitted into the center hole of the disc D due to the magnetic attraction force therebetween. Is completed. As shown in FIG. 7, at the time of completion of the disk clamp, the switch operation unit 33 provided on the left end of the slider 9 tilts the switch 35 to the back via the lever 34. Thus, the switch 35 detects the completion of the disk clamp and outputs a detection signal to the controller. When the controller receives the disc clamp completion detection signal, the loading motor 21
Stop driving. The release of the disc clamp and the unloading of the tray are performed in the reverse order of the above operation by rotating the loading motor 21 in the reverse direction. Next, the skew adjustment mechanism of the optical pickup will be described. As shown in FIGS. 3 and 8, the optical pickup 14 has two guide shafts 3 arranged in parallel with each other.
5 and 36, and are movably supported by them. The two guide shafts 35 and 36 are supported at both ends on the mechanical chassis 3 by the following structure. As shown in FIGS. 9 and 10, three of the four ends of the two guide shafts 35 and 36 are provided with a tilt adjusting cam 37 provided on the mechanical chassis 3 by outsert molding. Sitting on That is,
As shown in FIG. 10A, both ends of one guide 35 are supported on the mechanical chassis 3 via tilt adjusting cams 37, respectively. As shown in FIG. 10B, one end of the other guide shaft 36 is supported on the mechanical chassis 3 via a tilt adjusting cam 37, and the other end is outsert molded on the mechanical chassis 5. Is supported by the bearing 38 provided. As shown in FIG. 9, a cam 39 is formed on the upper surface of the inclination adjusting cam 37 in a spiral shape along the outer periphery. As shown in FIG. 10, a hexagonal hole (not shown) for adjusting the rotation angle is provided in a portion 37a of the tilt adjusting cam 37 protruding from the rear surface of the mechanical chassis 3, and the hexagonal hole is formed in the hexagonal hole. By inserting the bit 40 and rotating the tilt adjustment cam 37, the height of each end of the guide shafts 35 and 36 can be finely adjusted. One of the four ends of each of the guide shafts 35 and 36 has a bearing 38 in order to set a reference height at the time of skew adjustment using the inclination adjusting cam 37 of the other three ends. And is supported at a fixed height with respect to the mechanical chassis 3. However, the bearing 38 needs to have a bearing structure that allows the inclination of the guide shaft 36 supported by the bearing 38 to fluctuate. Each of the guide shafts 35 and 36 is held by a bearing 41 at a position near each of the tilt adjusting cams 37 so that the axial center position on the mechanical chassis surface does not change. Further, each of the guide shafts 35 and 36 is provided with a torsion spring 42 at a position between the inclination adjusting cam 37 and the bearing 41.
Is elastically pressed from above. Accordingly, the guide shafts 35 and 36 can be held at a fixed position in the height direction between the guide shafts 35 and 36 and the cam surface 39 of the tilt adjustment cam 37 while following the height fluctuation. A shaft holder 43 is provided above the inclination adjusting cam 37.
Are detachably fixed by snap fittings. The lower surface of the shaft holder 43 is formed so as to face the spiral cam surface 39 of the inclination adjusting cam 37 with a gap corresponding to the diameter of the guide shafts 35 and 36 interposed therebetween.
The shaft holder 43 rotates integrally with the tilt adjustment cam 37 during skew adjustment by fixing the snap fit with the tilt adjustment cam 37, and tilts even when a force is applied to the shaft holder 43 from below by the guide shafts 35, 36. The adjustment cam 37 does not come off. With the shaft holder 43, the guide shafts 35 and 36 can be stably held at a fixed position. That is, when the only means for pressing the guide shafts 35 and 36 from above is the torsion spring 42, for example, the guide shaft pushes up the torsion spring when receiving a strong impact due to dropping during transportation, as shown in FIG. In the worst case, the torsion spring 42 may be caught at the ends of the guide shafts 35 and 36, and the guide shafts 35 and 36 that have lost the pressing from above may be detached from the bearing 41. On the other hand, in the present embodiment, since the ends of the guide shafts 35 and 36 are more firmly held from above and below by the tilt adjusting cam 37 and the shaft holder 43, there is a concern that the guide shaft will jump from the cam surface even if a strong impact is received. Therefore, the guide shaft can be stably held. Here, a method of skew adjustment by the tilt adjustment cam 37 will be described. First, the three tilt adjusting cams 37 are rotated to align the guide shafts 35 and 36 in parallel with each other. Subsequently, these two guide shafts 35, 3
The tangential adjustment and the radial adjustment are performed so that the surface formed by 6 is parallel to the disk reproduction surface. The tangential adjustment is an adjustment for making the optical axis of the optical pickup orthogonal to the disk surface as viewed from the direction of the movement locus (normal line) of the beam spot on the disk reflection surface of the optical pickup. . In this tangential adjustment, one guide shaft 35 whose height at both ends can be displaced by the tilt adjustment cam 37 is moved up and down in parallel with the other guide shaft 36, that is, each of the guide shafts 35 on both sides is guided. This can be performed by rotating the tilt adjusting cams 37 in the same direction by the same amount of rotation. The radial adjustment is an adjustment for making the optical axis of the optical pickup orthogonal to the disk surface when viewed from a direction orthogonal to the normal on the disk surface. Therefore, this radial adjustment is performed by each guide shaft 3
The rotation can be performed by rotating the inclination adjusting cams 37 at the outer peripheral end portions of the disks 5 and 36 in the same direction by the same amount of rotation. Next, the optical pickup feed mechanism will be described. As shown in FIG. 8, the optical pickup feeding mechanism includes a pickup feeding motor 51 and this motor 5.
It is composed of gear groups 53 and 54 for reducing and transmitting the power of 1 to a rack gear 52 fixed to the optical pickup 14. Here, as shown in FIG. 12, the meshing state between the rack gear 52 fixed to the optical pickup 14 and the pinion 55 of the terminal gear 54 for power transmission is affected by the skew adjustment. In particular, when the guide shaft 36 is inclined with respect to the reference surface of the mechanical chassis 3, the pinion 5
There is a possibility that the meshing between the gear 5 and the rack gear 52 is twisted in the face width direction and the meshing is not performed normally. Therefore, in the present embodiment, as shown in FIG. 13, by providing a taper 56 on the teeth 52a of the rack gear 52, as shown in FIGS. On the other hand, the pinion meshes in a good condition. It is desirable that the taper angle θ be larger than the maximum inclination adjustment angle of the guide shaft. The taper may be provided not on the rack gear but on the pinion. Next, details of the tray will be described. As shown in FIGS. 1 and 14, the tray 1 has a concave portion 61 on which a disk is mounted, an opening 62 for inserting a turntable and reading a disk by an optical pickup, and a pickup feeding portion when the tray is inserted. A notch 63 is provided to avoid interference with the motor. Further, the tray 1 has a first protruding portion 65 for abutting a stopper provided at a fixed position in the mechanical chassis 3 to limit the discharge amount of the tray 1, and the tray 1 is located at a predetermined position. A second protrusion 66 is provided for operating a switch 35 (a switch also serving to detect completion of disc clamping) via the lever 34 for detecting that the sheet has been ejected. Specifically, each of the protrusions 65 and 66 is fixed to a plurality (two in this embodiment) of screw holes 67 arranged side by side in the loading direction on the tray 1 and one of the screw holes 67. It consists of a screw 68. Then, as shown in FIG.
The distal end portion 8 protrudes from the back surface of the tray 1 to a position where it can contact the stopper and the lever 34. As shown in FIGS. 16 and 17, the tray 1
When the screw 68 of the second protrusion 66 contacts the rising portion 34a of the lever 34 before the screw 68 of the first protrusion 65 contacts the stopper 70, the lever 34 is pivoted about the shaft 71. The switch 35 is turned in the direction of the arrow B to bring the switch 35 from the neutral state to the near side. In this case, a detection signal indicating that the unloading of the tray has been completed is output from the switch 35 to the controller, and the controller receives the detection signal and stops the loading motor 21. When the loading motor 21 overruns, the screw 68 of the first projection 65 comes into contact with the stopper 70 to restrict the discharge of the tray 1 there. As described above, in the present embodiment, a plurality of screw holes 67 are provided for each projection in the loading direction of the tray 1, and the screw 6 is inserted into one of the screw holes 67.
By fixing the tray 8, as shown in comparison with FIGS. 17 and 18, the discharge amount of the tray 1 can be easily changed. Thereby, when the present disk reproducing apparatus is combined with the design panel 73 having a design in which the tray entrance is depressed, each of the screw holes 6 on the front side of each of the projections 65 and 66 is provided.
By fixing the screw 68 to the tray 7 and reducing the tray discharge amount by the distance between the screw holes, the notch hole 63 for avoiding interference with the pickup feed motor in the tray discharge state is not exposed, and the appearance is impaired. Is gone. As described above, according to the present invention, it is possible to easily adjust the skew after assembling a product, and it is possible to adjust the skew on the disk surface without depending on the improvement of the accuracy of individual parts. The required verticality of the optical axis of the pickup can be obtained. Further, according to the present invention, by providing the tapered teeth of the pickup feed gear mounted on the teeth or the chassis of the rack gear attached to the optical pickup, guide to thus chassis reference plane skew adjustment Even in a state where the shaft is inclined, it is possible to ensure a normal meshing state between the gears.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a state of a disc reproducing apparatus of the present embodiment when a tray is ejected. FIG. 2 is a perspective view showing a state of the disc reproducing apparatus of FIG. 1 at the time of reproduction. FIG. 4 is an exploded perspective view showing a configuration of a reproducing mechanism unit in the disc reproducing apparatus of FIG. 1; FIG. 4 is an internal side view of the disc reproducing apparatus of FIG. 1; FIG. FIG. 6 is a plan view showing a state at the time of completion of tray loading of the disk reproducing apparatus of FIG. 1; FIG. 7 is a plan view showing a state at the time of completion of disk clamping of the disk reproducing apparatus of FIG. 1; FIG. 9 is a plan view showing a configuration on a mechanical chassis of the disk reproducing apparatus of FIG. 9; FIG. 9 is a perspective view showing details of a main part of a skew adjusting mechanism shown in FIG. 8; FIG. Side view of Fig. 1 1 is a perspective view showing a state of displacement of a torsion spring when receiving an impact in the skew adjustment mechanism of the present embodiment. FIG. 12 is a side view showing an optical pickup feed mechanism in the disk reproducing apparatus of FIG. FIG. 14 is a diagram for explaining a taper provided on a tooth of a rack gear of the optical pickup feed mechanism shown in FIG. 12; FIG. 14 is a plan view showing a structure of a tray of the disc reproducing apparatus of FIG. 1; FIG. FIG. 16 is a cross-sectional view showing the structure of the projection. FIG. 16 is a plan view showing the state of tray unloading for explaining the operation of the tray projection of FIG. 15. FIG. 17 is an illustration of the operation of the tray projection of FIG. FIG. 18 is a plan view showing a state at the time of completion of tray unloading. FIG. 18 shows a difference in tray discharge amount due to a difference in a position of a screw fixed to a tray protrusion in FIG. [Description of References] 1... Tray 2... Main Chassis 3... Mechanical Chassis 5... Reproducing Mechanical Unit 13... Disc Motor 14 ... Optical Pickup 21 ... Loading Motors 35 and 36. Guide shaft 37: tilt adjusting cams 38, 41 Bearing 39: spiral cam surface 42 of tilt adjusting cam Torsion spring 43 Shaft holder 51 Pickup feed motor 52 Rack gears 53, 54 ... gear 55 ... pinion 56 ... taper

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-94115 (JP, A) JP-A-2-181081 (JP, A) JP-A-8-197332 (JP, A) JP-A 62-94 261753 (JP, A) JP-A-10-64207 (JP, A) JP-A-10-134359 (JP, A) JP-A 4-49321 (JP, U) JP-A 61-105961 (JP, U) Japanese Utility Model Showa 61-195582 (JP, U) Japanese Utility Model Showa 63-87630 (JP, U) Japanese Utility Model Showa 4-132616 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 7/08-7/085 G11B 21/00-21/06

Claims (1)

(57) Claims: 1. A chassis; two guide shafts each having both ends supported by the chassis; an optical pickup supported by each of the guide shafts so as to be freely transportable; An adjusting member for individually adjusting the height of at least three of the four support points of each guide shaft from the reference surface of the chassis; a rack gear attached to the optical pickup; and the rack gear Optical pickups
Pickup, a power source for transporting along the
And a pickup feed motor mounted on the chassis and
One or more to transmit the power of the
A gear for pick-up feed, and before meshing with the teeth of the rack gear or the rack gear
The teeth of the pickup feeding gear are adjusted by the adjusting member.
The rack gear and the rack gear which may be generated by adjusting the height of the guide shaft.
Absorbs the relative inclination with the pickup feed gear and
A disc reproducing apparatus characterized in that a taper for correcting meshing between gears is provided .