JPS6112616Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a pick-up feeding device, and more particularly to an improvement in a device for linearly feeding a pick-up of a player that plays back recording media such as video discs and PCM records.

A typical example of a conventional pick-up feed device is to rotate a male threaded shaft having a male thread formed on its outer circumferential surface, and move a nut-shaped member having a female thread on its inner circumferential surface corresponding to the male thread in the axial direction.
There is a structure in which the pick-up is held by this nut-shaped member. However, conventional devices of this type have several points that should be improved. For example, a complex device is required that can constantly control the relationship between the rotational speed of a motor for rotating a video disk and the rotational speed of a motor for feeding a pickup. Furthermore, when sending pickups, it is desirable to have a configuration that allows pickups to be sent at two speeds, slow and fast during normal playback, but such a configuration may be relatively complex.

Therefore, the main object of this invention is to provide an improved pick-up feeding device which overcomes the above-mentioned problems.

Simply put, this invention is a pick-up feeding device that uses a differential screw mechanism to easily switch between slow feeding and fast feeding.

Other objects and features of the invention will become clearer from the detailed description given below with reference to the drawings.

1 to 3 are sectional views, FIG. 2 is a bottom view, and FIG. 3 is a left side view. FIG. 4 is a perspective view of the worm gear bearing portion as the main part of FIGS. 1 to 3. FIG. FIG. 5 is a cross-sectional view of the bearing portion of FIG. 4.

Referring to FIGS. 1 to 3, the drive motor 1
A rotary table 3 is attached to the shaft 2a, and the rotary table 3 holds a recording medium such as a video disc 4. A worm 5 is attached to the other shaft 2b of the drive motor 1. A stand 6 is provided fixedly to the drive motor 1, and bearings 7, 8, and 9 are provided on this stand 6. Bearing 7
, a first worm gear 1 meshing with the worm 5
0 is rotatably provided. The relationship between the first worm gear 10 and the bearing 7 is clearly shown in FIGS. 4 and 5.

Referring to FIGS. 4 and 5, the bearing 7 supports the first worm gear 10 in the radial direction. An annular groove 11 is formed on the outer periphery of the shaft portion of the first worm gear 10, and an annular groove 12 is provided on the inner periphery of the bearing 7 in correspondence with the groove 11. A C-shaped ring 1 is provided in both grooves 11 and 12.
3 is inserted. This fitting begins with bearing 7.
If the ring 13 is inserted into the groove 12 of the ring 13, the first worm gear 10 is guided from below in FIG.
The ring 13 is fitted into the first worm gear 1.
0 installation is completed.

A second worm gear 14 is disposed in a different position from the first worm gear 10 and parallel to the axis so as to mesh with the worm 5. This second worm gear 1
Numeral 4 is radially supported by a bearing 8, and the same mounting method as that for the first worm gear 10 is applied. Although detailed illustrations such as those shown in FIGS. 4 and 5 are omitted, the shaft portion of the second worm gear 14 and the bearing 8
An annular groove is formed in each of the grooves, into which a C-shaped ring 15 is fitted.

The first worm gear 10 and the second worm gear as described above.
According to the mounting manner of the worm gear 14, the ring 1
If the annular grooves 12 and the like of the bearings 7 and 8 and the corresponding annular grooves 11 of the worm gears 10 and 14 are made with precision, the worm gear 1
It is possible to prevent movement in the axial direction of 0 and 14, is easy to assemble, has a small number of parts, and can be molded with resin. The rings 13, 15 are preferably made of an elastic material, for example an oil-impregnated plastic material.

A female thread is formed on the inner peripheral surface of the first worm gear 10 . A male thread corresponding to this female thread is formed on the outer peripheral surface of the male threaded shaft 16, and the male threaded shaft 16 and the first worm gear 10 are coupled by meshing of the male thread and the female thread. Both ends of the male threaded shaft 16 are rotatably supported by frames 17 and 18. A gear 19 is arranged at one end of the male threaded shaft 16. The gear 19 is axially movable, as shown in phantom at 19a in FIG. 2, but is configured such that its rotation is integral with the externally threaded shaft 16.
That is, the configuration is realized by, for example, a spline or a key.

A guide shaft 2 is provided on the inner circumference of the second worm gear 14.
0 is inserted. The guide shaft 20 guides the second worm gear 14 so as to be movable in the axial direction, but is configured to rotate integrally with the second worm gear 14 . That is, for example, as clearly shown in FIG. 3, a rib protruding from the inner peripheral surface of the second worm gear 14 is configured to be received in the groove of the guide shaft 20. Both ends of the guide shaft 20 are
It is rotatably supported by frames 17 and 18. Guide shaft 2
A gear 21 is fixedly provided at one end of 0.

The gear 21 selectively meshes with the gear 19, and meshing is achieved when the gear 19 is in the position shown by the solid line in FIG. 2, and is disengaged when the gear 19 is in the position 19a. Although not shown,
The above-mentioned displacement of the gear 19 is achieved by engaging the sides of the fork gear 19 and moving this fork from side to side. Note that the gear 19 is at position 19a.
When it is in the position, it is designed so that it engages with the frame 17 and does not rotate. Further, a pick-up 22 (FIG. 1) is provided fixedly to the frame 17.

According to the configuration described above, the pair of gears 19, 21
By selectively controlling the engagement of the pick-up 22, one drive motor 1 can send the pickup 22 at two speeds, the fast backward speed of normal playback performance. Therefore, since the drive motor 1 alone can rotate the disk 4 and also feed the pickup 22, only the drive motor 1 needs to be controlled during playback. . Further, as long as the track pitch of the disk 4 is constant, the same mechanism may be used regardless of the system. The operation will be explained in detail below.

During slow forwarding during normal playback performance,
As the drive motor 1 rotates, a rotary table 3 and a video disk 4 are rotated. and,
Worm 5 is also rotating. Since the first and second worm gears 10 and 14 are meshed with this, the rotation is transmitted to each of them and rotated. Second
The worm gear 14 is on the guide shaft 20 and rotates the guide shaft 20, but is axially movable. The rotation of the guide shaft 20 is transmitted from the gear 20 to the male threaded shaft 16 via the gear 19, causing the male threaded shaft 16 to rotate. On the other hand, due to the rotation of the worm 5, the first worm gear 10 is also rotated. At this time, both the first worm gear 10 and the male threaded shaft 16 are rotating, and if the rotation speed and rotation direction are the same, the first worm gear 10 is located at a relative position on the male threaded shaft 16. do not change. If one of them is a little faster, it will move by the difference in the direction of the faster one. Therefore, when the pick-up 22 is to be fed slowly, it can be fed in the desired direction by meshing the gears 19 and 21 and rotating the male threaded shaft 16 a little faster or slower than the first worm gear 10. .

In order to feed the pick-up 22 quickly, it is sufficient to stop the rotation of the male threaded shaft 16. To do this, a fork (not shown) is moved to displace the gear 19 to position 19a, disengage it from the gear 21, and engage the gear 19 with the frame 17 so that the male threaded shaft 16
It is sufficient to prohibit the rotation of the . At this time, since the first worm gear 10 is being rotated, the first worm gear 10 is rotated according to the speed of rotation.
Move relative to the top.

It will be appreciated that the relative axial movement of the first worm gear 10 and the externally threaded shaft 16 causes the pick-up 22 to be moved. Here, the smaller the difference in the number of rotations applied to the first worm gear 10 and the male threaded shaft 16, the greater the speed ratio between slow feed and fast feed during reproduction performance. This difference can be made by providing a difference in the number of teeth between the first worm gear 10 and the second worm gear 14, or
This can be produced by providing a difference in the number of teeth between the gear 19 and the gear 21, or by providing a difference in both. For example, the first worm gear 10
29, the second worm gear 14 is 30, the gear 19 is 39,
If the gears 21 each have 40 teeth, the difference in rotational speed between the first worm gear 10 and the male screw shaft 16 can be as small as 1/117, so the difference between slow feed and fast feed can be reduced to 1/117. The speed ratio can be increased to 117 times.

Moreover, when the male threaded shaft 16 is a right-handed thread,
If the first worm gear 10 rotates clockwise, it moves to the left in FIG. 2 when the male threaded shaft 16 does not rotate. Move the male threaded shaft 16 to the right to the first worm gear 1
When turned a little faster than 0, the first worm gear 10 moves to the right at a slow speed. Therefore, the relative moving direction of the pick-up 22 is reversed depending on whether the play is slow or fast, so the arrangement is such that the pick-up 22 quickly returns to its original position when the reproduction performance is over and the switch is switched to fast forward. Can be done. Further, in order to enable slow feeding in the case of reproduction performance and fast feeding in the same direction, the male threaded shaft 16 may be designed to rotate slightly slower than the first worm gear 10.

In order to enable the above-mentioned fast feed both in the same direction as the slow feed and in the opposite direction, the second
An auxiliary motor 23 as shown by imaginary lines in the figure may be provided. This auxiliary motor 23 is directly connected to the male threaded shaft 16. In this case, two motors are used: the drive motor 1 and the auxiliary motor 23, but since the auxiliary motor 23 is used only for fast forwarding, power consumption during playback does not increase. It is inexpensive because there is no need to control the rotation speed.

FIG. 6 is a diagram for explaining another embodiment of this invention, and corresponds to FIG. 2 of the embodiment. In FIG. 6, parts corresponding to those shown in FIG. 2 are given the same reference numerals, and detailed explanations are omitted.

A different configuration will be described with reference to FIG. 6. A guide rod 24 is received in bearings 8 and 9 provided on the stand 6 so as to be movable in the axial direction. Also,
A second motor 25 is provided connected to the male threaded shaft 16 .

This embodiment has the following features compared to the previous embodiments. That is, in the above embodiment, in order to rotate the male threaded shaft 16, the rotation of the drive motor 1 is transmitted to the second worm gear 14,
In this example, the male threaded shaft 16 was rotated via the guide shaft 20, gear 21, and gear 19.
The male threaded shaft 16 is rotated by a second motor 25. If the second motor 25 is one that can be controlled in rotation over a wide range, it is possible to perform slow feed or fast feed in any direction during normal playback performance.

As described above, according to this invention, since a differential screw mechanism is used for pick-up feeding, slow feeding and fast feeding can be performed by simple switching. Furthermore, for example, it is possible to realize slow playback from the outer periphery of the disc.
It can be arbitrarily selected at the design stage.

[Brief explanation of the drawing]

1 to 3 show an embodiment of this invention, in which FIG. 1 is a front view, FIG. 2 is a bottom view, and FIG. 3 is a left side view. FIG. 4 is a perspective view showing the bearing portion of the first worm gear shown in FIGS. 1 to 3. FIG. FIG. 5 is a cross-sectional view of FIG. 4.
FIG. 6 is a diagram corresponding to FIG. 2 for explaining another embodiment of this invention. In the figure, 1 is a drive motor, 3 is a rotary table, 4 is a video disk as a recording medium, 5 is a worm, and 10 is a first rotating body with internal threads.
A worm gear, 14 is a second worm gear, 16 is a male screw shaft, 19 and 21 are gears, 20 is a guide shaft, 2
Reference numeral 2 indicates a pickup, and reference numeral 25 indicates a second motor as a means for driving the rotation of the male screw shaft.

Claims (1)

[Claims for Utility Model Registration] (1) A rotary body with a female thread, which rotates by being transmitted to the rotary table from a drive motor that drives a rotary table that holds a rotating recording medium, and has a female thread formed on its inner peripheral surface. , means for fixing the relative positional relationship between the axis of the rotary table and the axis of the rotating body; a male threaded shaft having a male thread corresponding to the female thread formed on its outer peripheral surface; and a rotational drive for rotating the male threaded shaft. means, a pick-up that moves in unison with the relative movement of the male threaded shaft in the axial direction, and means for selectively stopping rotation of the male threaded shaft by the rotation drive means, and the female threaded rotating body and the male threaded shaft, and when the male threaded shaft is rotated under the control of the selective stopping means, the pick-up relatively moves at a minute speed; A pick-up feed device configured to relatively move in the pick-up rapid feed mode when the male threaded shaft is stopped. (2) The male threaded shaft rotation drive means is combined with the drive motor, a second rotation body rotated by the drive motor, and the second rotating body to rotate integrally but to be movable in the axial direction. and a gear device that transmits the rotation of the guide shaft to the male threaded shaft.
The pick-up feeding device described in (1). (3) The pick-up feeding device according to claim (2), wherein the selective stopping means includes a configuration for disconnecting a pair of gears included in the gear device. (4) The pick-up feeding device according to claim (1), wherein the male screw shaft rotation drive means includes a second motor. (5) The pick-up feeding device according to claim 4, wherein the selective stopping means includes means for turning on and off the second motor. (6) The relative positional relationship between the axis of the drive motor and the axis of the rotary table is fixed, and the means for fixing the relative positional relationship between the axis of the rotary table and the axis of the rotating body is The pick-up feed according to any one of claims (1) to (5) of the utility model registration claim, which includes a base for fixing the drive motor and bearing the internally threaded rotating body so as not to move in the axial direction. Device. (7) An annular groove is formed in the outer periphery of the female threaded rotor and the inner periphery of the bearing portion of the base in a portion where the base bears the female threaded rotating body, and an elastic groove is formed in both grooves. The pick-up feeding device according to claim 6, wherein movement in the axial direction is prohibited by fitting a certain C-shaped ring.