JPH0917134A - Feed mechanism - Google Patents

Abstract

PURPOSE: To prevent a deadlock state of a feed mechanism of optical pickup or the like. CONSTITUTION: A helical gear 10b is provided which is meshed with a helical gear 10a to which a driving force of a motor is transmitted by a worm gear and a rack formed integrally with an operating part. The helical gear 10b transmits the driving force of the helical gear 10a. Since the helical gears 10a and 10b are attracted by a magnetic force to transmit the driving force, it is prevented that the helical gears 10a and 10b idle in a deadlock state when an overload is applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeding mechanism used for an optical pickup feeding mechanism of an optical disk device.

[0002]

2. Description of the Related Art A feed mechanism for moving an optical pickup of an optical disc apparatus along a track of an optical disc is constructed by utilizing a driving force of a motor. A schematic configuration of a conventional optical pickup feeding mechanism will be described with reference to FIG. 1 and the helical gear shown in FIG. In the figure, in a drive unit that moves an optical pickup 8 that is an operating unit of the optical pickup feed mechanism 1, a motor 3 having a worm gear 6 attached to a drive shaft 5 is fixed to a housing 2 by a fixing member 4.

Further, two parallel guide rails 7a and 7b are fixed to the housing 2 in the axial direction of the drive shaft 5 of the motor 3, and the optical pickup 8 integrally mounts a rack 9 by a helical gear 10 '. It is driven and moved by sliding on the guide rails 7a and 7b. The helical gear 10 ′ is rotatably engaged with the shaft 13 provided in the housing 2, meshes with the worm gear 6, and the driving force from the motor 3 is transmitted to the rack 9. Motor 3
By controlling the motor 3 from the control circuit (not shown), the optical pickup 8 is moved on the guide rails 7a and 7b and positioned on the track of the opposing disk, and the reproducing operation can be performed.

[0004]

However, when the control of the motor 3 becomes impossible due to malfunction or failure of the control system for driving and controlling the motor 3, the optical pickup 8 runs away to a position where the worm gear 6 cannot move. There is a drawback that it bites into the helical gear 10 ', mechanically enters a deadlock state, and it becomes impossible to restart.

[0005]

According to the present invention, there is provided a rack connected to an operating portion which slides on a guide rail fixed to a casing, and a first gear which meshes with the rack and moves the operating portion. A helical gear, a motor fixed to the housing and having a worm gear attached to a drive shaft, a second helical gear meshing with the worm gear, and the first and second helical gears are coaxially axially coupled to each other by a magnetic force. The feeding mechanism is provided with a transmission portion that sucks and transmits a driving force and idles when overloaded.

[0006]

Therefore, since the transmission portion for transmitting the driving force of the first and second helical gears due to the magnetic force at the time of overload idles, the worm gear continues to idle even if the control operation by the motor runs out of control. A deadlock condition can be prevented.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows a schematic configuration diagram of an embodiment of a feeding mechanism according to the present invention. In addition,
The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.
In the figure, a magnet 11 integrally held by a helical gear 10b meshed with a worm gear 6 attached to a drive shaft 5 of a motor 3 and a magnetic attraction member 12 such as iron held integrally by the helical gear 10a face each other. And the helical gears 10a and 10b are coaxially supported on the housing 2 by the shaft 13 so that the helical gear 10a is mounted on the optical pickup 8.
Engages with the rack 9 that is integrally connected with.

The optical pickup feed mechanism 1 drives the worm gear 6 by the motor 3, and the worm gear 6 transmits the worm gear 6 to the helical gears 10b and 10a.
Is transmitted to the rack 9 and the rack 9 controls the optical pickup 8 to a predetermined position along the guide rails 7a and 7b. The control circuit (not shown) has some trouble and the motor 3
When the rack 9 moves to a position where it cannot move when it continues to rotate in a certain rotation direction, and the helical gear part is suppressed, the helical gear 10a and the helical gear 10b have a synergistic combined force of the force due to the magnetic force and the drag force at the contact portion. With the overload, the idle rotation can be prevented, and the bite into the worm gear 6 and the helical gear 10b can be prevented.

[0009]

According to the present invention, the transmission portion of the helical gear for transmitting the driving force of the worm gear of the feed mechanism is provided with the transmission means by magnetic force, and it is allowed to idle at the time of overload. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a feeding mechanism according to the present invention.

FIG. 2 is a partial cross-sectional view of a main part of the present invention.

FIG. 3 is a schematic configuration diagram showing a conventional example.

[Explanation of symbols]

 1 Optical Pickup Feeding Mechanism 2 Housing 3 Motor 4 Fixing Member 5 Drive Shaft 6 Worm Gear 7a, 7b Guide Rail 8 Optical Pickup 9 Rack 10a, 10b, 10 'Helical Gear 11 Magnet 12 Plate 13 Shaft

Claims (1)

[Claims] 1. A rack connected to an operating portion that slides on a guide rail fixed to a casing, a first helical gear that meshes with the rack and moves the operating portion, and the casing. A motor having a fixed worm gear attached to a drive shaft, a second helical gear meshing with the worm gear, and the first and second helical gears are coaxially engaged with each other and are attracted by a magnetic force to transmit the driving force. A feed mechanism comprising a transmission section that idles when loaded.