JPH09293341A - Lead screw for optical disk drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lead screw by which a pickup is driven at high speed and with high accuracy and which is manufactured at low costs by a method wherein a spiral groove is formed on the surface of a metal rod by the outsert molding operation of a resin. SOLUTION: In an optical pickup driving mechanism for an optical disk drive unit, a spiral groove Bc is extended and formed in a constant direction in the axial direction on the surface of a lead screw B which is turned and driven via a driving gear from a driving motor. An optical pickup Pa is provided with a feed tooth Pb so as to be engaged with the spiral groove Bc, and the pickup is positioned as the lead screw B is turned and operated so as to be moved rectlinearly along the lead screw B. At this time, when the lead screw B is manufactured, a metal rod Ba is prepared, and a resin Bb in which the spiral groove Bc is extended and formed is outsert-molded. The cutting operation and the polishing operation of the metal rod are not required, and the coefficient of friction of respective parts on the surface of the lead screw is kept nearly constant in any parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead screw for moving an optical pickup for recording / reproducing information to / from a recording medium to a predetermined position in an optical disk drive device or a magneto-optical disk drive device.

[0002]

2. Description of the Related Art Conventionally, an optical disk drive device has driven various disk-shaped recording media such as an optical disk and a magneto-optical disk by a spindle motor to rotate and scan the recording surface of the recording medium with an optical pickup in the radial direction. This is a device for recording / reproducing data.

A conventional turntable of a disk drive will be described with reference to the drawings. FIG. 3 is a plan view of the optical pickup drive mechanism of the first conventional example, and FIG. 4 is an axial sectional view of the same lead screw. In the figure, α is an optical pickup drive mechanism, A is a lead screw, P is an optical pickup,
Reference numeral 1 is a drive motor, and 2 is a drive gear.

The optical pickup drive mechanism α shown in FIG.
A drive motor 1, a drive gear 2 connected to the drive shaft of the drive motor 1, and a lead screw A which is connected to the drive gear 2 and has a surface on which a spiral groove 2 is threaded around a constant axial direction.
And the spiral groove Ac of the lead screw A meshes with the feed dog Pb of the optical pickup Pa, and the optical pickup P moves linearly while being positioned on the lead screw A as the lead screw A rotates. It consists of and.

As a procedure for producing the lead screw A, first, a spiral groove Ac is threaded on the surface of the metal rod Aa by cutting. Next, the surface of the metal rod Aa in which the spiral groove Ac was cut was processed by polishing.

[0006]

However, the lead screw A of the conventional example has the following drawbacks. First, in the cutting process and the polishing process of the metal rod, the friction coefficient of each part of the surface of the lead screw A varies due to the surface roughness of the cutting process or the polishing process, and the driving load of the drive motor 1 changes. As a result, there is a drawback that the feeding operation of the optical pickup cannot be performed at high speed and with high accuracy.

Secondly, there is a drawback that the manufacturing cost is increased because the cutting process and the surface polishing process of the metal rod which are relatively troublesome are required.

Here, an object of the present invention is to provide a lead screw for an optical disk drive which can drive an optical pickup at high speed with high accuracy and can be manufactured at low cost.

[0009]

In order to solve the above-mentioned problems, the present invention adopts the following novel concrete solving means. That is, a feature of the present invention is a lead screw of an optical disk drive device, which is composed of a metal rod and a resin in which a spiral groove is extendedly formed on the surface of the metal rod by outsert molding.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of an optical pickup driving mechanism of this embodiment, and FIG. 2 is an axial sectional view of the same lead screw. In the figure, β is an optical pickup drive mechanism, B is a lead screw, P is an optical pickup, 101 is a drive motor, and 102 is a drive gear.

The optical pickup driving mechanism β shown in FIG.
A drive motor 101, a drive gear 102 connected to a drive shaft of the drive motor 101, a lead screw B connected to the drive gear 102 and having a spiral groove Bc extending on the surface around the surface in a constant axial direction, and the lead. The spiral groove Bc of the screw B and the feed dog Pb of the optical pickup Pa mesh with each other, and the optical pickup P is linearly moved while being positioned on the lead screw B as the lead screw B rotates. ing.

The lead screw B is produced by preparing a metal rod Aa and outsert-molding the resin Bb having the spiral groove Bc extendingly formed therein.

[0013]

As described above, by adopting the lead screw of the present invention, firstly, there is no need for cutting processing and polishing processing of the metal rod, and it is possible to reduce the surface roughness of the cutting processing and polishing processing. The friction coefficient of each part of the surface of the lead screw is maintained substantially constant everywhere, and there is an advantage that the driving load of the drive motor does not fluctuate and the high-speed and high-precision feeding operation of the optical pickup can be performed.

Secondly, there is an advantage that the manufacturing cost is reduced because the cutting process and the surface polishing process of the metal rod which are relatively troublesome are unnecessary.

[Brief description of drawings]

FIG. 1 is a plan view of an optical pickup driving mechanism according to an embodiment of the present invention.

FIG. 2 is an axial sectional view of the same lead screw.

FIG. 3 is a plan view of a conventional optical pickup driving mechanism.

FIG. 4 is an axial sectional view of the same lead screw.

[Explanation of symbols]

 α, β Optical pickup drive mechanism A, B Lead screw P Optical pickup 1,101 Drive motor 2,102 Drive gear

Claims (1)

[Claims] 1. A lead screw for an optical disk drive device, comprising a metal rod and a resin in which a spiral groove is extendedly formed on the surface of the metal rod by outsert molding.