JPH0519855Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tilt drive mechanism suitable for use in optical video disc players and the like.

[Background technology]

In an optical video disc player, a slider equipped with a pickup is moved in the radial direction of the disc in order to reproduce recorded signals from the inner circumference to the outer circumference of the disc. by the way,
Optical video discs have a larger radius than compact discs, so they are more likely to warp.
Therefore, the angle of the slider with respect to the disk is controlled so that the light output from the pickup is incident approximately perpendicularly to the disk at any radial position. The mechanism for this purpose is a tilt drive mechanism.

In conventional tilt drive mechanisms, the angle of a tilt base on which a slider is mounted is adjusted using a motor, a cam, or the like. Further, a stopper is provided at a predetermined position to restrict movement of the tilt base so that the angle to be adjusted does not exceed a predetermined range.

[Problem that the invention attempts to solve]

As described above, the conventional tilt drive mechanism described above simply provides a mechanical stopper in order to regulate the tilt adjustment angle. Therefore, if the tilt drive motor goes out of control due to a runaway of the microcomputer, etc. used to control the tilt angle, the tilt base may dig into the stopper, making it impossible to return it to the normal range. It was hot.

The present invention was developed in response to these circumstances, and even if the tilt drive motor runs out of control, it can reliably deal with the runaway. It is an object of the present invention to provide a tilt drive mechanism that can smoothly return to within the range.

[Means for solving problems]

In order to achieve the above object, the tilt drive mechanism of the present invention includes a first gear rotated by the driving force of a tilt drive motor, and a tilt drive mechanism that rotates while meshing with the first gear. A second gear having a toothless portion that releases the meshing force with the gear, a cam body having a cam groove that rotates in synchronization with the rotation of the second gear, and a pin that fits into the cam groove. have,
By receiving the displacement force by the cam groove,
A tilt base to which rotational force is applied, a protrusion formed at a predetermined position of the cam body or the second gear, and the second gear rotate, and the toothless part engages with the first gear. a limiter plate having an elastic force that comes into contact with the protrusion and prevents rotation of the cam body or the second gear when the meshing force with the first gear is released upon reaching the position; It is characterized by having the following.

[Effect]

In the tilt drive mechanism of the present invention, when the first gear is rotated by the driving force of the tilt drive motor, this rotational force is transmitted to the second gear meshing with the first gear. A cam body having a cam groove is integrally connected to the second gear, and as the cam body rotates, a pin fitted into the cam groove receives displacement force, and the tilt base rotates. move.

Here, when the tilt drive motor runs out of control, for example, when the cam body or the second gear rotates by a predetermined amount, a protrusion formed at a predetermined position of the cam body or the second gear comes into contact with the limiter plate. In this state, since the toothless portion of the second gear has reached the meshing position with the first gear, the meshing force between the first gear and the second gear is cut off. The transmission force from the first gear to the second gear can be cut off.

In addition, in this state, the elastic force of the limiter plate applies a pushing back force in the opposite direction to the cam body or the second gear through the protrusion that is in contact with the limiter plate. Alternatively, when attempting to rotate the second gear in the opposite direction, the meshing state between the first gear and the second gear can be easily obtained.

〔Example〕

Hereinafter, details of embodiments of the tilt drive mechanism of the present invention will be described based on the drawings.

1 to 3 show an embodiment of the tilt drive mechanism of the present invention.

In these figures, 71 is a tilt drive motor, and 72 is a worm rotated by the motor 71. The rotation of the worm 72 is transmitted to a gear 73 that is integrally connected to a gear 74. 1st
A gear 74 as the second gear meshes with a gear 75 as the second gear.

The gear 75 is integrally connected to a cam body 77A having a cam groove 77. A protrusion 78 is formed at a predetermined position on the cam body 77A. Note that this protrusion 78 may be provided at a predetermined position on the gear 75 side. In addition, a toothless portion 76 is provided at a predetermined position of the gear 75.
is provided. Here, the positional relationship between the protrusion 78 and the toothless part 76 is such that when the tilt motor 71 runs out of control and the protrusion 78 of the cam body 77A abuts a limiter plate 81, which will be described later, It is said to be the position where the mesh is released.

These members are assembled via the plate 79 and attached to the mechanical plate 41. The mechanical plate 41 includes the above-mentioned tilt motor 7.
A limiter plate 81 made of synthetic resin or the like and having an elastic force is attached so that it comes into contact with the protrusion 78 and prevents the rotation of the cam body 77A when the cam body 77A runs out of control. In addition, the limiter plate 81 is
Since it has elastic force, it also has the effect of pushing back the protrusion 78 slightly.

Tilt base 3 placed on mechanical plate 41
A slider motor 1 is attached to the slider. Reference numeral 4 denotes a rod-shaped screw having a thread formed on its surface, and is rotatably supported by the tilt base 3 via a rotation bearing 5. 6 is Natsuto,
It is screwed onto the screw 4. A slider 21 is attached to the nut 6, and a pick-up 22 is attached to the slider 21. A shaft 23 guides the sliding of the slider 21, and is inserted into and fixed to the bearing 7 of the tilt base 3.

A base plate 42 is fixed to the mechanical plate 41. The base plate 42 is located on the back side of the tilt base 3.
The pin 43 is inserted into the cam hole 45 of the cam plate 44 via the elongated hole 8 of the tilt base 3. The pin 46 of the cam plate 44 is inserted into the hole 9 of the tilt base 3. The screw 48 is screwed into the hole 10 of the tilt base 3 through the hole 47 of the cam plate 44. Thereby, the cam plate 44 is rotatably attached to the tilt base 3 using the pin 46 as a fulcrum.

Here, when the cam plate 44 rotates counterclockwise around the pin 46 (when the adjustment piece 11 rotates clockwise around the fulcrum 12), the tip of the adjustment piece 11 moves counterclockwise around the pin 46. (rotating clockwise), the pin 43 moves upward and to the right within the arc-shaped cam hole 45. Since the pin 43 is fixed and cannot be moved, the pin 46 tries to move toward the lower left. However, since the elongated hole 8 formed in the height direction prevents movement to the left, the pin 46 (and therefore the tilt base 3) eventually descends.

On the other hand, when the cam plate 44 rotates clockwise, the tilt base 3 rises by an operation opposite to the above. Furthermore, since the screw 48 attached to the tilt base 3 is inserted into the hole 47 of the cam plate 44, the cam plate 4 on the tilt base 3 is inserted into the hole 47 of the cam plate 44.
The amount of rotation of the hole 47 is regulated by the size of the hole 47.

Furthermore, 61 is a spindle motor, 62 is a turntable rotated by the spindle motor 61, and these are inserted into the hole 51 of the mechanical plate 41 and fixed.

The tilt drive mechanism having such a configuration operates as follows.

First, when the motor 1 is driven to move the pick-up 22 in the radial direction of the disk, the gear 15 attached to the screw 4 passes through the gear 13 attached to the drive shaft of the motor 1 and the belt 14. Rotational force is transmitted to. As a result, the screw 4 rotates in a predetermined direction,
A feeding force is applied to the nut 6, and the pick-up 22 mounted on the slider 21 is slid in the radial direction of the disk.

Here, when tilt control is performed, the motor 7
1 is driven. The driving force of the motor 71 is applied to the cam body 7 via a worm 72 and gears 73, 74, 75.
7A.

When the cam body 77A rotates due to the driving force of the motor 71, a displacement force is applied to the pin 82 of the tilt base 3 that is fitted into the cam groove 77 of the cam body 77A. That is, when the cam body 77A rotates in the direction of arrow a, the pin 82 of the tilt base 3 moves upward. On the other hand, when the cam body 77A rotates in the direction of arrow b, the pin 82 of the tilt base 3 moves downward. Therefore, such a pin 82
Due to the displacement, the tilt base 3 rotates clockwise or counterclockwise about the pin 43 as a fulcrum. At this time, since the spring 18 interposed between the mechanical plate 41 and the mechanical plate 41 always urges the tilt base 3 upward, the tilt base 3 is prevented from wobbling during rotation. .

Here, for example, while rotating the tilt base 3 clockwise about the pin 43, the motor 7
1 goes out of control for some reason, the cam body 77
A rotates by a predetermined amount or more in the direction of arrow b. Cam body 7
When 7A rotates by a predetermined amount or more, its protrusion 78 comes into contact with the limiter plate 81, so the cam body 7
The rotational movement of 7A is blocked. At this time, gear 7
Since the toothless portion 76 of No. 5 reaches the meshing position with the gear 74, the meshing state between the gear 74 and the gear 75 is released. This reliably prevents unnecessary rotation of the cam body 77A due to runaway of the motor 71.

On the other hand, when trying to rotate the cam body 77A in the opposite direction from the above from this state, the elastic force of the limit plate 81 exerts a slight pushing force against the protrusion 78, so the gear 74 is rotated. When rotated in the opposite direction to the above, engagement with the gear 75 is obtained by the pushing force, and the tilt base 3 is smoothly rotated in the opposite direction to the above.

〔effect〕

As described above, according to the tilt drive mechanism of the present invention,
A protrusion that contacts the limiter plate is provided at a predetermined position on the cam body or the second gear, and the second gear is provided with a meshing force with the first gear while the protrusion is in contact with the limiter plate. A missing tooth was created at the location where the tooth was cut off.

Therefore, if the tilt drive motor runs out of control, the rotation of the cam body or the second gear is blocked by the protrusion and toothless part that come into contact with the limiter plate, so the tilt drive motor will not run out of control. can be dealt with reliably.

In addition, in this state, due to the elastic force of the limiter plate, a push-back force in the opposite direction acts on the cam body or the second gear through the protrusion that is in contact with the limiter plate, and the cam body or the second gear is pushed back from that position. If you try to rotate the second gear in the opposite direction, you can easily get the meshing state with the first gear, so you can smoothly rotate the second gear in the opposite direction from when the cam body or second gear runs out of control. You can make it happen.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of the tilt drive mechanism of the present invention, Fig. 2 is an assembled perspective view thereof, and Fig. 3 is an exploded perspective view of the tilt drive mechanism of the present invention.
It is a vertical perspective view of the main part of a figure. 1... Motor, 3... Tilt base, 4... Screw, 5... Rotating bearing, 6... Nut, 7...
... Bearing, 8 ... Long hole, 9, 10 ... Hole, 11 ...
Adjustment piece, 12... Fulcrum, 13... Gear, 14...
Belt, 15...Gear, 18...Spring, 2
1...Slider, 22...Pickup, 23...
...Shaft, 41...Mechanical chassis, 42...Base plate, 43...Pin, 44...Cam plate,
45...cam hole, 46...pin, 47...hole, 4
8...screw, 49...recess, 51...hole, 61...
...spindle motor, 62...turntable,
71...Motor, 72...Worm, 73,7
4, 75...Gear, 76...Missing teeth, 77...Cam groove, 77A...Cam body, 78...Protrusion, 79...
...Plate, 81...Limitsuta plate, 82...
…pin.

Claims (1)

[Claims for Utility Model Registration] A first gear rotated by the driving force of a tilt drive motor;
a second gear having a toothless portion that releases the meshing force with the first gear; a cam body having a cam groove that rotates in synchronization with rotation of the second gear; and a cam body having a cam groove that rotates in synchronization with rotation of the second gear; a tilt base that has a pin that fits therein and is provided with a rotational force by receiving a displacement force from the cam groove; a protrusion formed at a predetermined position of the cam body or the second gear; When the second gear rotates and the toothless portion reaches the meshing position of the first gear and the meshing force with the first gear is released, the toothless portion comes into contact with the protrusion and the cam body or a limiter plate having an elastic force that prevents rotation of the second gear.