JP4042158B2 - Optical pickup traveling drive device for disk device - Google Patents

Description

  According to the present invention, an optical pickup traveling drive device for a disk device, in particular, an inclination angle adjustment (tilt adjustment) of the optical pickup is performed by changing the height of a guide member for guiding the traveling of the optical pickup. In addition, the present invention relates to an optical pickup traveling drive device for a disk device in which the rotational movement of a drive gear is converted into a linear motion by meshing the drive gear and a rack so that the optical pickup travels.

  A disk device that adjusts the tilt angle of an optical pickup by changing the height of a guide member that guides the traveling of the optical pickup has been known (Patent Document 1), and its schematic configuration is shown in FIG. . In the figure, 1 is a main shaft, 2 is a sub shaft, 3 is an optical pickup, 4 is a spindle motor for rotating the turntable, 5 is a chassis, and 6 is provided at one end of the main shaft 1 and at both ends of the sub shaft 2, respectively. The tilt adjustment mechanism 7 is a decenter adjustment mechanism provided at the other end of the main shaft 1. In this disk device, tilt adjustment is performed by changing the height of the main shaft 1 and the sub shaft 2 by operating the tilt adjustment mechanism 6.

  FIG. 10 and FIG. 11 illustrate a conventional example of a traveling drive device of the optical pickup 3 that can be employed in such a disk device. As shown in FIGS. 10 and 11, the travel drive device includes a rack 10 provided in the optical pickup 3 and a drive gear 50 as a pinion that meshes with the rack 10. The spur gear provided with the gear tooth 51 in which the streak line is formed in a straight line is employed, and the rack tooth 11 of the rack 10 is also formed in the straight line. 10 and 11, 8 is an optical actuator, and 70 is an intermediate gear integrated with the drive gear 50. The rotation of a motor (not shown) is transmitted to the intermediate gear 70.

  On the other hand, it is known to use a rack and pinion system as a disk transport device for loading a cartridge such as an MD disk into a disk player (see, for example, Patent Document 2), and a recording medium cartridge loading mechanism is configured. In order to achieve this, it is also known to combine a moving lever provided with a rack and a drive gear (for example, see Patent Document 3). On the other hand, in a gear transmission mechanism for traveling a traveling body in a vertical direction and a horizontal direction on a flat plate, a technique for maintaining a meshing ratio above a certain level by using a gear meshing with a vertical rack strip as an involute gear has been conventionally known. (See Patent Document 4).

JP 2000-20962 A JP 2001-52406 A JP 2003-85861 A JP-A-10-267100

By the way, in the traveling drive device of the optical pickup adopting the meshing structure of the drive gear 50 and the rack 10 described with reference to FIGS. 10 and 11, the respective tooth trace lines of the rack teeth 10 and the drive gear 50 are straight lines. 11, when the reference line P of the rack 10 shown in FIG. 11 is tilted and displaced from the initial position as indicated by the arrow a or b due to the height variation caused by the tilt angle adjustment (tilt adjustment described above) of the optical pickup 5. At the initial position, the tooth line of the rack tooth 11 that is parallel to the tooth line of the gear tooth 51 is inclined with respect to the tooth line of the gear tooth 51. Therefore, the tooth tip of the gear tooth 51 and the rack tooth A relative shift occurs in the angle formed by the 11 tooth tips, the meshing state deteriorates, and the tendency of biting between gear teeth or the biting tendency becomes obvious, increasing the operating load. Occurs. In order to solve this point, to keep adding dimensions capable of shallow meshing depth between the gear teeth 51 and rack teeth 11 on the axis-to-axis dimension of the drive gear 50 and the rack 10 It is effective to provide a sufficient margin in the meshing state in advance, but if so, depending on the degree of tilt adjustment, so-called backlash is likely to occur due to rattling of the meshing portion, and the traveling function of the optical pickup 3 As a result, the disk scanning performance by the optical actuator 8 may be deteriorated.

  On the other hand, the techniques described in the above-mentioned Patent Documents 2 and 3 are techniques related to loading of a cartridge, and are not related to a travel drive device for an optical pickup, but also include the tilt angle as described above. It does not provide a technique for solving the increase in the operation load accompanying the adjustment and the occurrence of backlash. In addition, the technique described in Patent Document 4 merely shows the use of an involute gear for smoothly running a traveling body in a vertical direction and a horizontal direction on a flat plate, and an optical pickup in a disk device. It does not provide a technique for solving the increase in operation load and the occurrence of backlash associated with the tilt angle adjustment.

  The present invention has been made in view of the above situation, and even if the rack reference line fluctuates from the initial position due to the tilt adjustment of the optical pickup, the gear teeth of the drive gear and the rack teeth of the rack are tilted. By taking measures to make the meshing state less likely to fluctuate, it is possible to avoid an increase in operating load associated with the tilt angle adjustment without reducing the meshing depth between the gear teeth and the rack teeth. An object of the present invention is to provide an optical pickup traveling drive device for a disk device that can easily solve the problem of backlash.

An optical pickup travel drive device for a disk device according to the present invention is a rack provided in the optical pickup, wherein the inclination angle of the optical pickup traveling by being guided by the guide member is adjusted by changing the height of the guide member. And a drive gear for driving the optical pickup by meshing with the rack and applying a feeding force, wherein the rack teeth have a circular cross section and the rack The teeth are formed in a truncated cone shape, and a configuration is adopted in which the tooth profile curve of the meshing surface of the gear teeth with respect to the rack teeth is an involute curve . Further, a configuration is adopted in which the gear teeth have a circular cross-sectional shape, the gear teeth are formed in an involute rotating body shape, and the meshing surface of the rack teeth with the gear teeth is a flat surface. It is also possible.

  With this configuration, even if the rack reference line fluctuates from the initial position with inclination adjustment, the rack teeth of the rack or the gear teeth of the drive gear have a circular cross-sectional shape. The meshing state does not change. For this reason, there is no room for an increase in the operating load due to the change in the meshing state, and the problem of backlash is also improved since it is not necessary to provide a sufficient margin in the meshing state in advance.

As described above, according to the present invention, even if the rack reference line fluctuates from the initial position in accordance with the tilt adjustment of the optical pickup, the meshing state of the rack teeth of the rack and the gear teeth of the drive gear varies. do not do. For this reason, there is no room for an increase in the operating load due to the change in the meshing state, and the problem of backlash is also improved since it is not necessary to provide a sufficient margin in the meshing state in advance.

  FIG. 1 is a schematic plan view of a main part of an optical pickup traveling drive apparatus according to a first embodiment of the present invention, FIG. 2 is a schematic side view thereof, FIG. 3 is a partially enlarged perspective view of a rack 10, and FIG. The top view of a meshing location and the same (B) are the operation explanatory views shown with the expanded sectional view of the portion which meets the IVB-IVB line of (A).

In the optical pickup driving apparatus of the first embodiment shown in FIGS. 1 and 2, the vertically long rack teeth 11 of the rack 10 described with reference to FIGS. 10 and 11 are changed to a circular cross-sectional shape. . More specifically, as shown in FIG. 3, the rack teeth 11 are formed in a truncated cone shape. For the gear teeth 51 of the drive gear 50, the tooth profile curve of the meshing surface 52 is an involute curve. A point where the optical pickup 3 travels while being guided by a main shaft or a sub shaft (see FIG. 9) as a guide member, a point where the tilt angle of the optical pickup 3 is adjusted by changing the height of the main shaft or the sub shaft, etc. Is the same as that described with reference to FIGS. 9, 10, and 11.

  In this configuration, the operation when the tilt angle of the optical pickup 3 is adjusted and the reference line P of the rack 10 shown in FIG. 2 is displaced from the initial position in the direction of the arrow a will be described with reference to FIG. To do. 4A and 4B, P1 illustrates the reference line of the rack 10 after being displaced from the initial position in accordance with the tilt angle adjustment. 52 is a meshing surface of the gear teeth 51 with respect to the rack teeth 11, A is a contact position between the rack teeth 11 and the meshing surfaces 52 of the gear teeth 51 when the reference line P is located at the initial position, and A1 is The contact positions between the rack teeth 11 and the meshing surfaces 52 of the gear teeth 51 after the rack 10 is displaced by the tilt adjustment are shown. As can be seen from FIG. 4B, the meshing surfaces 52 of the gear teeth 51 before and after the tilt angle adjustment, although the rack teeth 11 are displaced from the solid line position to the phantom line position. Is in contact with only one circumferential direction of the outer peripheral surface of the rack tooth 11 having a circular cross-sectional shape. In other words, the meshing state of the gear teeth 51 and the rack teeth 11 does not vary before and after the tilt angle adjustment. Therefore, there is no room for an increase in the operating load due to the change in the meshing state, and it is not necessary to provide a sufficient margin in the meshing state in advance, so that the problem of backlash is also improved. The same effect is exhibited when the reference line P of the rack 10 is tilted and displaced from the initial position in the direction of arrow b shown in FIG. 2 by adjusting the tilt angle of the optical pickup 3.

  FIG. 5 is a schematic plan view of a main part of an optical pickup traveling drive apparatus according to the second embodiment of the present invention, FIG. 6 is a schematic side view thereof, FIG. 7 is an explanatory diagram, and FIG. The figure and (B) are the action explanatory views shown with the expanded sectional view of the part which met the VIIIB-VIIIB line of (A).

  In the optical pickup driving apparatus according to the second embodiment shown in FIGS. 5 and 6, the shape of the longitudinal gear teeth 51 of the driving gear 50 described with reference to FIGS. 10 and 11 is changed to a circular cross-sectional shape. Is. More specifically, the gear teeth 51 are formed in an involute rotating body shape. The involute rotating body shape described above is a shape formed by rotating the involute curve L about the axis M, as is apparent from the explanatory diagram shown in FIG. Therefore, the tooth profile curve of the meshing surface 53 of the gear tooth 51 formed in the involute rotating body shape with respect to the rack tooth 11 is an involute curve.

  The shape of the rack teeth 11 of the rack 10 is the same as that of the conventional example described with reference to FIGS. 10 and 11, that is, a vertically long shape in which the tooth traces form a straight line. The meshing surface 12 is a flat surface. A point where the optical pickup 3 travels while being guided by a main shaft or a sub shaft (see FIG. 9) as a guide member, a point where the tilt angle of the optical pickup 3 is adjusted by changing the height of the main shaft or the sub shaft, etc. Is the same as that described with reference to FIGS. 9, 10, and 11.

  In this configuration, the operation when the tilt angle of the optical pickup 3 is adjusted and the reference line P of the rack 10 is displaced from the initial position in the direction of arrow a shown in FIG. 6 will be described with reference to FIG. To do. 8A and 8B, P1 illustrates the reference line of the rack 10 after being displaced from the initial position in accordance with the tilt angle adjustment. B is a contact position between the rack teeth 11 and the meshing surfaces 53 of the gear teeth 51 when the reference line P is located at the initial position, and B1 is the rack teeth 11 after the rack 10 is displaced by adjusting the inclination angle. The contact positions of the gear teeth 51 with the meshing surface 53 are shown. As can be seen from FIG. 8 (B), the inclination of the meshing surface 12 of the rack tooth 11 before and after the inclination angle adjustment is circular even though the inclination of the meshing surface 12 of the rack tooth 11 is displaced from the solid line position to the virtual line position. The meshing surface 53 of the gear tooth 51 having the transverse cross-sectional shape is in contact with the meshing surface 12 of the rack tooth 11 only at one circumferential direction. In other words, the meshing state of the gear teeth 51 and the rack teeth 11 does not vary before and after the tilt angle adjustment. Therefore, there is no room for an increase in the operating load due to the change in the meshing state, and it is not necessary to provide a sufficient margin in the meshing state in advance, so that the problem of backlash is also improved.

  In this embodiment, since the tooth profile curve of the meshing surface 53 of the gear tooth 51 is an involute curve, an accurate meshing state can be obtained even if the accuracy of the inter-axis distance varies due to mounting errors, and the drive gear The rack is smoothly fed by the rotation of.

It is a schematic plan view of the principal part of the optical pick-up travel drive apparatus which concerns on 1st Embodiment of this invention. It is the same schematic side view. It is a partial expansion perspective view of a rack. (A) is a top view of a meshing part, (B) is an effect explanatory view shown in the expanded sectional view of the portion which meets the IVB-IVB line of (A). It is a schematic plan view of the principal part of the optical pick-up travel drive apparatus which concerns on 2nd Embodiment of this invention. It is the same schematic side view. It is explanatory drawing of an involute rotary body shape. (A) is a top view of a meshing part, (B) is an operation explanatory view shown in the expanded sectional view of the portion which meets the VIIIB-VIIIB line of (A). It is the top view which illustrated the schematic structure of the conventional disc apparatus which can adjust an inclination. It is a schematic plan view of a conventional example. It is a schematic side view of a prior art example.

Explanation of symbols

1 Main shaft (guide member)
2 Secondary shaft (guide member)
3 Optical pickup 10 Rack 50 Drive gear 51 Gear teeth 52, 53 Gear teeth meshing surface

Claims (2)

By adjusting the tilt angle of the optical pickup that travels while being guided by the guide member, the height of the guide member is changed, and the rack provided on the optical pickup is engaged with the rack to provide a feeding force. In the optical pickup traveling drive device of the disk device comprising the drive gear for traveling the optical pickup,
The rack teeth have a circular cross-sectional shape, the rack teeth are formed in a truncated cone shape, and the tooth profile curve of the meshing surface of the gear teeth with respect to the rack teeth is an involute curve. An optical pickup travel drive device for a disk device. By adjusting the tilt angle of the optical pickup that travels while being guided by the guide member, the height of the guide member is changed, and the rack provided on the optical pickup is engaged with the rack to provide a feeding force. In the optical pickup traveling drive device of the disk device comprising the drive gear for traveling the optical pickup,
A disk device characterized in that the gear teeth have a circular cross-sectional shape, the gear teeth are formed in an involute rotating body shape, and the meshing surface of the rack teeth with the gear teeth is a flat surface. Optical pickup travel drive device.

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