JPH08167258A - Mobile object supporting mechanism - Google Patents

Abstract

PURPOSE: To prevent the vibration of a mobile object from occuring during the movement. CONSTITUTION: A 1st guide shaft 12 and a 2nd guide shaft 13 are arranged on the main body of an information recording/reproducing device so as to be respectively parallel and uneven, and an optical head 11 is supported by these 1st guide 12 and 2nd guide shaft 13 so as freely to perform the linear reciprocating motion. Voice coil motors 20 are arranged at both ends of the optical head 11, and a working point of driving force of these voice coil motors 20 is positioned near the center of gravity of the optical head 11. The center of gravity of the optical head 11 is positioned near the center W on a line connecting axial centers of the 1st guide shaft 12 and 2nd guide shaft 13 to each other. The moment by the inertial force of the optical head 11 does not occur on the line connecting the axial centers of the 1st guide shaft 12 and 2nd guide shaft 13 to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body supporting mechanism used for an information recording / reproducing apparatus for recording / reproducing information on / from a recording medium and for supporting a moving body such as an optical head so as to be linearly movable. .

[0002]

2. Description of the Related Art In recent years, an optical information recording / reproducing apparatus for optically recording / reproducing information on / from a recording medium has been widely used.
Recording media such as compact discs, magneto-optical discs, and optical cards are used in this type of information recording / reproducing apparatus. The information recording / reproducing apparatus is provided with an optical head for scanning the information recording medium at a high speed. The optical head is supported by guide shafts parallel to each other so as to be linearly movable and driven by a voice coil motor or the like. It has become.

For example, as shown in the front sectional view of FIG. 4 and the plan view of FIG. 5, the optical head 1 is located in the track direction A of the optical card C above the optical card C held on a mounting table (not shown). It is movably arranged. Both ends of the optical head 1 are supported by a first guide shaft 2 and a second guide shaft 3 which are fixed in parallel to the main body of an information recording / reproducing apparatus (not shown). Between the optical head 1 and the first guide shaft 2, there are interposed bearing pairs 4a and 4b which symmetrically contact the first guide shaft 2 from diagonally above and diagonally below, respectively.
Between the guide shafts 3, the bearings 5a and 5b are in contact with the second guide shaft 3 obliquely from above, and the bearings 5 are in contact with the second guide shaft 3 from obliquely below.
and c are interposed. The bearing pairs 4a and 4b are provided at two places, and the bearings 5a and 5b are preloaded by the leaf spring 6. A voice coil motor 7 is arranged on both ends of the optical head 1, and a voice coil 8 of the voice coil motor 7 is fixed to the optical head 1.

As described above, in the information recording / reproducing apparatus in which the optical head 1 is supported, the optical head 1 includes the voice coil motor 7
Is driven in the direction A, and the optical card C placed on the mounting table is driven in the direction B, so that information is transferred to the optical card C.
Will be recorded and played back.

[0005]

However, in the above-mentioned conventional example, the center of gravity of the optical head 1 and the point of action of the voice coil motor 7 are located at the respective center axes of the first guide shaft 2 and the second guide shaft 3. Since it is separated from the connecting line, when the optical head 1 is accelerated or decelerated, the inertial force of the optical head 1 causes the space between the first guide shaft 2 and the second guide shaft 3 to be connected to each other. A moment is generated, and the optical head 1 vibrates greatly in the automatic focusing direction and the automatic tracking direction, which impairs the reliability of the information recording / reproducing apparatus.

An object of the present invention is to solve the above-mentioned problems and to provide a moving body supporting mechanism capable of improving the reliability of the information recording / reproducing apparatus by reducing the moment generated in the moving body. is there.

[0007]

In order to achieve the above object, a moving body supporting mechanism according to the present invention includes a moving body driven by a voice coil motor, a first guiding shaft and a second guiding shaft which are parallel to each other. In a moving body supporting mechanism that supports linear movement by the guide shafts, the first guide shaft and the second guide shaft are fixed in different steps, and the first guide shaft and the second guide shaft are fixed.
At least one of the center of gravity of the moving body and the operating point of the voice coil motor is located near the center of the line connecting the axis centers of the guide shafts.

[0008]

In the moving body supporting mechanism having the above structure, the first
The guide shaft and the second guide shaft are arranged in different steps, and the center of gravity of the moving body and the action of the voice coil motor are provided in the vicinity of the center on the line connecting the shaft centers of the first guide shaft and the second guide shaft. Since at least one of the points is positioned, the moment due to the inertial force of the moving body is reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a front sectional view of the first embodiment,
FIG. 2 is a plan view showing that the optical head 11 has the first guide shaft 12
Also, linear reciprocating motion is freely supported in the direction Y by the second guide shaft 13. The first guide shaft 12 and the second guide shaft 13 are fixed to a main body of an information recording / reproducing apparatus (not shown), being parallel to each other and having an angle θ.

Between the optical head 11 and the first guide shaft 12, there are interposed bearing pairs 14 and 15 which come into contact with the first guide shaft 12 obliquely from above and below, respectively. Between the optical head 11 and the second guide shaft 13, there are interposed bearings 16 and 17 that come into contact with the second guide shaft 13 from diagonally above and bearings 18 that come into contact with the second guide shaft 13 from diagonally below. The bearing pairs 14 and 15 are provided at two locations near the side edge of the optical head 11, and the bearings 16 and 17 are provided to a leaf spring 19 fixed to the optical head 11 to be preloaded.

Voice coils 21 of a voice coil motor 20 are fixed to both ends of the optical head 11. A center yoke 22 is arranged inside the voice coil 21,
A back yoke 24, to which a permanent magnet 23 is fixed inside, is arranged outside the voice coil 21.

Here, the voice coil motor 20 is arranged so that its driving force acts in the vicinity of the center of gravity of the optical head 11. The point of action of the voice coil motor 20 and the center of gravity of the optical head 11 are located near the center W on the line connecting the respective axes of the first guide shaft 12 and the second guide shaft 13.

With such a structure, the optical head 11 is driven by the voice coil motor 20 by the driving force of the first guide shaft 12.
And is driven in the direction Y along the second guide shaft 13. At this time, the optical head 11 is biased by the leaf spring 19 and
Rattling between the guide shaft 12 and the second guide shaft 13 is prevented.

The point of action of the voice coil motor 20 and the center of gravity of the optical head 11 are located near the center W on the line connecting the respective axes of the first guide shaft 12 and the second guide shaft 13. Therefore, even if the driving force of the voice coil motor 20 changes and the optical head 11 is accelerated or decelerated, the moment due to the inertial force of the optical head 11 does not occur, and the moment is extremely small.

Therefore, the vibration of the optical head 11 in the automatic focusing direction and the automatic tracking direction can be prevented, and the reliability of the information recording / reproducing apparatus can be improved.

FIG. 3 shows a second embodiment. In the first embodiment, the bearings interposed between the first guide shaft 12 and the second guide shaft 13 are slide bearings 25 and 26, respectively. .

As described above, there is no problem even if the slide bearings 25 and 26 are used without using a ball bearing as the bearing.

[0018]

As described above, in the moving body support mechanism according to the present invention, the first guide shaft and the second guide shaft are arranged in different steps, and the first guide shaft and the second guide shaft are arranged. At least one of the center of gravity of the moving body and the action point of the voice coil motor is located near the center of the line connecting the axes of the moving body to reduce the moment due to the inertial force of the moving body. Therefore, the reliability of the information recording / reproducing apparatus can be improved.

[Brief description of drawings]

FIG. 1 is a front sectional view of an example.

FIG. 2 is a plan view.

FIG. 4 is a front sectional view of a conventional example.

FIG. 5 is a plan view of a conventional example.

[Explanation of symbols]

 11 optical head 12 first guide shaft 13 second guide shaft 16, 17, 25, 26 bearing 19 leaf spring 20 voice coil motor 21 boil coil

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[Procedure amendment]

[Submission date] April 20, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a front sectional view of an example.

FIG. 2 is a plan view.

FIG. 3 is a front sectional view of another embodiment.

FIG. 4 is a front sectional view of a conventional example.

FIG. 5 is a plan view of a conventional example.

[Explanation of reference numerals] 11 optical head 12 first guide shaft 13 second guide shaft 16, 17, 25, 26 bearing 19 leaf spring 20 voice coil motor 21 boil coil

Claims (1)

[Claims] 1. A moving body support mechanism for linearly movably supporting a moving body driven by a voice coil motor by means of a first guide shaft and a second guide shaft which are parallel to each other. The shaft and the second guide shaft are fixed in different steps, and the center of gravity of the moving body and the action of the voice coil motor are provided in the vicinity of the center on the line connecting the shaft centers of the first guide shaft and the second guide shaft. A movable body support mechanism, characterized in that at least one of the points is positioned.